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Mine rescue training must begin with the basic knowledge of self contained breathing apparatus(SCBA) and the primary apparatus that you will be required to wear. This manual is to familiarize yourself to the apparatus, don the apparatus correctly, wear the apparatus in smoke or confined space, and to react properlt in case of failure in any part the SCBA.

II. Development of SCBA

The history of the development of self-contained breathing apparatus goes quite far back in time, though in the early days most of the attention was given to designing a unit to protect firemen from smoke inhalation.

One such design for firemen dates back to about 1825 when the "smoke filter" was used. It consisted of a leather hood and a hose that was strapped to one of the wearer's leg. It did not contain its own supply of oxygen. Rather, it was designed so that when the wearer inhaled from inside the hood, air would be drawn up through the hose.

The idea behind this design was that the best air during a fire is closest to the floor. The hose and hood was intended to provide this better air to the firemen as they worked in smoke.

Soon after, equipment was designed to provide the firemen with good safe air to breathe for short periods of time. One such design was the "supplied air suit" which was filled with fresh air to breathe.

Another design for firefighters was a bag-like unit filled with fresh air and carried on one's back, much like some of today's units.

Underwater divers also used some of the first self contained breathing apparatus developed.

Then, in 1853, self-contained breathing apparatus was introduced for use in the mines by a Professor Schwann of Belgium. In that year, Schwann entered a self-contained breathing apparatus in a competition of the Belgian Academy of Science, and exhibited it at an industrial fair in Belgium.

In 1880, the original Fleuss apparatus was introduced in England, and in 1903 the original Draeger apparatus was developed in Germany.

In the United States, breathing apparatus were introduced in 1907 when five Draeger units were purchased by the Boston and Montana Mining Company in Butte, Montana.

Records show that also in 1907, apparatus were first used to fight fires and explore ahead of fresh air in the mines:

In October or November of 1907, Draeger apparatus were used by a crew of men during the fighting and sealing of a mine fire at the Minnie Healy Mine of the Boston and Montana Mining and Smeiting Company in Butte, Montana.
On December 6, two Draeger apparatus were used to explore ahead of fresh air after an explosion in the Monongah Mine of the Consolidated Coal Company in Monongah. West Virginia.
On December 19, apparatus were used after an explosion in the Darr Mine of the Pittsburgh Coal Company in Jacobs Creek, Pennsylvania.

In 1910, the Bureau of Mines was established. The Bureau began equipping mine rescue railroad cars and stations with apparatus and began training miners in the use and care of the breathing apparatus. Thus, the equipment necessary for rescue work and the trained teams to use it gradually became more available to the mines.

At first, all the apparatus used in this country were imported from Europe. Then in 1918, the Gibbs apparatus was designed and manufacture. This was followed by the Paul in 1920 and the McCaa in 1927. These early American-made apparatus were designed for 2-hour use.

The development of self-contained breathing apparatus has continued to progress through the years. A number of different manufacturers are now producing apparatus that are approved to be used for periods of 2, 3, and 4 hours at a time. Among these apparatus commonly used for mine rescue work are the Draeger BG 174, the Aerolox, and the Scott Rescue-Pak.

III. Types of SCBA

a. Open and Closed Circuit SCBA- Self-contained breathing apparatus can be divided into two main categories: open circuit systems and closed circuit systems. The basic difference between the two systems is this: An open circuit system releases all of your exhaled air (carbon dioxide) to the outside atmosphere through a valve in the facepiece, and supplies you with fresh air to breathe. A closed circuit system does not release the exhaled air. Rather, it recirculates the air through the apparatus and purifies the air, taking out the carbon dioxide and adding fresh oxygen to the air. You are then supplied with the air that has been oxygen enriched.

b. Primary and Auxiliary SCBA- In mine rescue work, apparatus are classified as being either "primary" or "auxiliary" apparatus depending on how much air or oxygen they can supply to you when you wear them. Primary apparatus are apparatus that have a minimum of 2 hours' service time. Auxiliary apparatus are units which provide, by law, 30 to 60 minutes' service time.

Primary apparatus are the standard apparatus that mine rescue teams use. Part 49 of Title 30 of the Code of Federal Regulations (30 CFR) specifies that rescue teams must be provided with self-contained breathing apparatus that have at least a 2-hour service time and are approved under Federal guidelines.

Auxiliary apparatus are only acceptable for a mine rescue team member to use so long as the team member has ready access to fresh air and has at least one rescue team equipped with an approved self-contained breathing apparatus of 2-hours or longer rating in reserve at the fresh air base.

Auxiliary apparatus may either be open or closed circuit systems. Primary apparatus, on the other hand, are designed as closed circuit systems.

c. Apparatus Approval- In order for any self-contained breathing apparatus to be used in mine rescue work, the apparatus must first be approved by the Federal movement.

Back in 1918, the Bureau of Mines began to test and approve apparatus under Schedule 13 which established the standards for approval.

Today, the testing of the apparatus is handled by the National Institute for Occupational Safety and Health (NIOSH). The apparatus approval is granted jointly by NIOSH and the Mine Safety and Health Administration (MSHA).

IV. History of mine rescue

a. Helmet Crews- In 1910, however, the U.S. Bureau of Mines was formed, and with it came the organization, training, and ''team" element that mine rescue so badly needed.

The Bureau established a network of specially outfitted railroad cars and placed them at strategic locations throughout the mining areas of the United States. Each car served as a base of operations for a group of individuals trained and equipped specifically for mine rescue work.

Because their breathing gear's full head covering resembled a deep sea diver's helmet, the groups became known as "helmet crews." The crews were trained to respond quickly and professionally to disasters in their own districts, much as modern teams do.

The new helmet crews were called on to lend a hand at several major disasters, and they were responsible for saving the lives of scores of trapped miners. Although the crew's access to breathing gear and other equipment was a great help to them, their success could be attributed to more than that.

For the first time, the rescuers had the training and organization they needed to turn an uncoordinated, often even chaotic, rescue attempt into a well coordinated efficient group effort. The birth of the early helmet crews clearly marked the beginning of modern mine rescue teams.

b. The 1940's- In the 1940's, World War II spurred increasing demand for mined products, so more miners were put to work. At the same time, the mines were becoming more highly mechanized. These factors combined to produce more hazards, and the result was more chance for disaster.

In terms of sheer numbers, the disaster statistics of the 40's came nowhere near matching those of earlier years, but they were nonetheless sobering. In 1940, for example, the Bartley No. 1 coal mine in West Virginia claimed 91 lives. In 1942. 56 died in the Christopher No. 3 coal mine disaster also in West Virginia. And a disaster at the Centralia No. 5 coal mine in Illinois claimed 111 lives in 1947.

These tragedies pointed to the need for preventing disasters by reducing the hazards that led to them. There were big changes afoot. Even though mining was a hazardous occupation, there were ways to make it safer.

On the state and Federal levels, this meant establishing and enforcing laws aimed at making the mines safer places in which to work. Mining companies also joined in the effort to reduce mining hazards by developing safety programs and improving conditions within the mines. To some extent, the changes worked. The number of disasters decreased, as did the number of those who died in them.

Today, great emphasis is still placed on establishing and enforcing mine health and safety regulations. This continues to significantly reduce mining hazards. Modern technological advances and increased mechanization have also made it possible for fewer miners to remove ever-increasing amounts of materials from beneath the earth's surface. This reduction in the number of man-hours required to do work has also reduced the chance for disaster.

c. Recent Disasters- Although these changes have helped reduce the incidence of disaster in the mines, they have not totally eliminated the problem. Disaster still haunts the mining industry. This becomes all too evident as you call to mind some of the disasters that have taken place in recent years.

Witness, for example, the tragedy that took place at the Sunshine Mine in Kellogg, Idaho when 91 miners died from fire and carbon monoxide poisoning in 1972. In 1968, 78 miners died in an explosion al the Farmington No. 9 mine in West Virginia. In that same year, 26 miners died in a disaster inside the Belle Isle Salt Mine in Louisiana. In 1980, an explosion claimed 5 lives at the Ferrel No. 17 coal mine in southern West Virginia. And, in 1981, a methane explosion in the Dutch Creek No. 1 coal mine near Redstone, Colorado killed 15 miners.

d. Mine rescue today- The mine rescue teams today's miners depend on are a far cry from their earlier counterparts. Rescues are no longer disorganized, haphazard affairs taken on by whoever happens to be in the area at the time of the disaster. Today's rescues are highly organized efforts carried out by a group of individuals working together as a team.

Recent developments in mine rescue emphasize two very important areas: training the teams, and improving the equipment they use.

For example, the new Federal requirements for mine rescue, which we'll talk about later on, set minimum standards for setting up, training, and equipping mine rescue teams. The law stresses that each member of the team must have practical training, and it sets guidelines for equipment maintenance and inspection. This helps to ensure that well-trained, properly equipped teams will be ready to work quickly and efficiently during an actual emergency.

Today's teams also have modern technology to thank for the increasingly sophisticated array of equipment they use to supplement their efforts. Early apparatus crews could count on their scabs to provide only one or two hours of breathing protection. Today's teams have much longer duration apparatus, plus many other devices that their predecessors, armed primarily with shovels, picks, and hatchets, probably never even dreamed of.

Today's team, for example, use modern gas detection and communication equipment. They also have at their command the latest technique and devices for sealing mines and fighting fires.

The computer age has also provided mine rescue with seismic locators, geophones, and other devices used to pinpoint trapped miners. These are all a part of MSHA's

Mine Emergency Operations (MEO), along with two National Mine Rescue Teams-one for coal mines and one for metal/nonmetal mines.

MSHA MEO also possesses the opability to drill boreholes down from the surface to reach miners who, in an earlier time would have been given up for dead. Once a borehole is drilled with what's known as a "survival drill," rescuers can lower cameras, lights, and microphones into the mine to help locate the miners, determine their situation, and lend support and assistance while an escape route is drilled. Once that is complete, the trapped miners can be safely hauled to the surface in specially designed "escape capsules." Rescue teams in some areas (such as Pennsylvania and Utah) also have access to another advanced form of supplementary mine rescue equipment-the mobile mine rescue van.

Designed for use during prolonged rescue efforts, these vans are equipped to serve as a base of operations for one or more teams throughout a rescue. The vans are outfitted with standard mine rescue gear such as breathing aphanites, recharging facilities, hand tools, and first aid supplies.

Some of the vehicle can boast the additional distinction of being virtual "moving laboratories," equipped with computers and other devices sophisticated enough to perform delicate tests like on-site gas analysis-a time consuming task previously performed only in distant laboratories.

V. Mine rescue and the law

a. Before Part 49- Until recently, 311 underground mines were not required to have access to mine rescue teams. Many of the teams now in existence were set up voluntarily -often in reaction to the tragedy of a major disaster. Other mines often followed suit, realizing that even though they had not experienced a disaster, it paid to be ready for one.

Many state departments of mines set up teams of their own so that they too would be ready to lend a hand if a disaster should occur. MSHA also trained and outfitted its own teams to ensure they would be ready to respond at a moment's notice to a disaster anywhere in the United States.

b. Part 49- It wasn't until recently, however, that the U.S. Congress passed laws making it mandatory for every mine in the country to have access to mine rescue teams. These regulations are contained in Part 49 of Title 30 of the Code of Federal Regulations (30) "Part 49", as we'll refer to it here, will have far-reaching consequences for mine rescue. For one thing. by making it mandatory for every mine to have rescue teams available, it will greatly increase the number of teams throughout the country.

Part 49 also specifies how many members each team should have, what equipment they should have on hand, and how the equipment is to be stored and maintained. The law also contains requirements for the notification plan to be used during an emergency.

Part 49 also specifies what physical standards and other qualifications you must meet to be eligible for team membership, and it sets some minimum standards for the amount and type of training you receive. According to law, if you're a new mine rescue team member, you must have least 20 hours of instruction on how to use, care for, and maintain the breathing apparatus.

Once you've completed this initial training, the law requires that you have at least 40 hours of additional training, every year as long as you're on the team. This is known as "advanced refresher training. As part of this advanced refresher training, the law requires that you have at least one underground session every six months. The law also specifies that you practice under oxygen for at least two hours every two months during your refresher training.

Besides "reviewing" your basic apparatus skills, your 40-hour advanced/refresher course will introduce you to advanced mine rescue skills, keep you abreast of changes, and give you a chance to do some practical, problem-solving work.

c. Eligibility- As we mentioned earlier, Part 49 also designates what standards make you eligible for team membership. For instance, the law says that in order to be on a team you must have worked in an underground mine for at least one year during the past years. You also qualify if you're employed on the surface but regularly work underground.

The law also specifies what physical standards you must meet in order to become a team member.

d. Mine Rescue Station and Equipment- Another part of the law requires that a mine rescue station be established "to provide a centralized storage location for mine rescue equipment." The rescue station is where you'll store and maintain equipment so it will be ready to use immediately during an emergency.

The law also specifies what equipment must be available at the mine rescue station. For instance, according to law, the station must be outfitted with at least twelve self- contained breathing apparatus, equipment necessary to test them, and enough carbon dioxide absorbent chemicals and oxygen to supply six hours of breathing protection for each team member.

The law also requires that the rescue station be provided with at least twelve permissible cap lamps, facilities to recharge them, two gas detectors for each type of gas found in the mine, and two oxygen indicators or flame safety lamps. According to law, there must also be an approved mine rescue communications system at the rescue station, and you must be provided with enough spare parts and other tools to maintain both the communications system and the breathing apparatus. The law also tells how your apparatus and other equipment should be maintained. It specifies how often equipment should be checked, by whom, and how Iong records of these tests must be kept on file. With reference to this, the law says:

"Mine rescue apparatus and equipment shall be maintained in a manner which will assure readiness for immediate use. A person trained in the use and care of breathing apparatus shall inspect and test the apparatus at intervals not exceeding 30 days. A record of inspections and tests shall be maintnined at the mine rescue station for a period of one year."

To receive NIOSH and MSHA approval, selfcontained breathing apparatus must meet specific requirements as to design and construction, and must operate satisfactorily during a specified series of actual wearing tests. The exact requirements for approval are outlined in Title 30, of the Code of Federal Regulations (30CFR), Part 1 ].

Certain apparatus approved formerly under Schedule 13 by the Bureau of Mines have been "conditionally approved" under 30 CFR and can still be used if manufactured and purchased before June 30, 1975, and if the apparatus has been properly maintained.

The McCaa apparatus is an example of an apparatus approved under Schedule 13 and still acceptable for mine rescue work.

e. Approval Labels- AlI approved apparatus are required by law to display an approval label on the unit. This label must bear the MSHA label and the sea1 of NIOSH, an approval number, and the name of the apparatus's manufacturer.

In addition to this, the label tells:

l. The type of apparatus (compressed oxygen, liquid oxygen, and so forth);

2. The approved service time of the apparatus (for instance, 2 or 3 hours);

3. The part numbers for component parts approved to be used with the apparatus (such as the facepiece part number or the breathing bag part number);

4. The limitations of the apparatus (such as the temperature range for use of the apparatus); and

5. Any special precautions that should be taken while using the apparatus. An apparatus approved under Schedule 13 will not have a current NIOSHl/MSHA approval label on it. However, the apparatus should carry a Bureau of Mines approval label, bearing the seal of the Bureau and listing information similar to that on the current NIOSH/MSHA approval labels.

All approvai labels should be read carefully so that the apparatus can be used in an approved manner. Also, if you should ever be in a situation where you are using an apparatus which is new to you (perhaps another team's equipment), the label will give you some basic information to help familiarize you with the apparatus.

VI. Wearing the apparatus

When you enter a mine as a mine rescue team, you may find yourself in smoke or poisonous gases, or not enoueh oxygen to keep you alive. That is why you wear an apparatus in mine rescue work. The apparatus will prorect your lungs from smoke and poisonous gases, and provide safe air for you to breathe.

There are, however, some conditions under which the apparatus will not entirely protect you:

1. Self-contained breathing apparatus will not protect you from toxic amounts of poisonous gases, dusts, or vapors that may injure your skin or be absorbed through your skin into your system. For example, fairly high concentrations of ammonia will injure your skin and hydrogen cyanide can be absorbed through your skin.

2. Your apparatus will not protect you if it is worn extensively in petroleum vapors. These vapors will permeate and deteriorate the rubber parts of the apparatus.

3. In air which is much above normal atmospheric pressure(14.7 pounds per square inch), it can be dangerous to wear an apparatus that supplies you with pure or nearly pure oxygen. Special precautions and procedures from the apparatus's manufacturer which allow the safe use of breathing apparatus under high atmospheric pressure should be followed.

a. Limitations of Wearing an Apparatus- Wearing any apparatus has its limitations. That is, there are things it cannot do and special factors you should take into consideration whcn you wear it.

In general, seeing. speaking, moving, working, and breathing are all a little different when you are wearing the apparatus. Understanding these differences and learning to cope with them can have a significant arfect on how well you do your job.

Apparatus designed by various manufacturers are all going to be a bit different. You will be practicing wearing and working with your apparatus so that you can get used to the feel of it and how it works.

For now, we will talk generally about what it's like to wear an apparatus and what the general limitations are.

b. Time Limit, Work Rate, and Breathing Rate- Any self-contained breathing apparatus that you use will limit the time you'll have in which to work underground. Your apparatus wiil be approved for a specified amount of time per wearing called the "service time."

The service time is established assuming that you work at a moderate rate. If you work extremely hard, you will be breathing faster and you will be consuming your oxygen or air at a faster rate. Also, nervousness or excitement can cause you to breath faster; and use more oxygen. In addition, the roughness of the terain you must travel and the heat and humidity of the area you will be in can affect your breathing rate and consequently, the service time. You should try to avoid breathing too quickly while wearing the apparatus. Short, shallow breathing or panting causes you to get an insufficient amount of oxygen and you may begin to feel faint. So if you find yourself breathing quickly, try to control your breathing and slow it down.

Also, you will probably experience some resistance to breathing while wearing the apparatus' facepiece. This is is caused by the air pressure in the facepiece. With practice and familiarity with the apparatus, you should be able to compensate for this resistance.

c. Weight and Size of Apparatus- The requirements for apparatus approval specify that an apparatus can weigh up to 40 pounds. This extra weight you will be wearying will affect your endurance, your rate of work. and your maneuverability. Therefore you will have to practice working with the apparatus on so that you can get used to moving and working with the extra weight and bulk.

One thing to remember while wearing the apparatus:All vour movements should be slow and deliberate.

d. Seeing- The requirements for apparatus approval specify that facepieces be designed and constructed to provide adequate vision. Still, when you wear the facepiece, you will find yourself turning your head and body more often than usual to see things around you.

Remember again: All movements while wearing the apparatus should be slow and deliberate.

Also, the heat and moisture produced within some of the apparatus can cause the facepiece to fog, making it difficult for you to see. Yet there are special "anti-fog" solutions that can be applied to the facepiece lens to help prevent it from fogging up on you.

e. Speaking- It is going to be more difficult to communicate while wearing the facepiece because your voice will be distorted. All the facepieces have a speaking diaphragm to transmit your voice to the outside of the facepiece but they tend to muffle your voice. You may find yourself having to speak a little louder and slower than usual in order to be understood. Also, you should try to talk as little as possible while wearing the apparatus. This means to cut our all unnecessary "chatter" so that only important information is communicated.

f. Facepiece Seal- When you wear the facepiece, it is extremely important to have a good tight seal around your face. This is known as the face-to-facepiece seal, or simply as the facepiece seal.

A good seal will prevent smoke and poisonous gases from leaking into the facepiece and infiltrating your air supply. It will also prevent any inadvertent leak of oxygen or air from inside the facepiece to the outside atmosphere.

So it is very importanr to tighten your facepiece snugly to your face and test it to make sure there aren't any leaks. Such things as very prominent cheekbones or deep scars could prevent a good seal. Other conditions that prevent a good facepiece seal are: (1) eyeglasses. and (2) beards and bushy sideburns, which are not recommended to be worn with any breathing apparatus.

Eyeglasses can prevent a good face-to-facepiece seal and should not be worn with many types of facepieces. Sometimes, however, eyeglasses will fit within the facepiece without disturbing the facepiece seal. Some facepieces even allow for the insertion of corrective lenses directly into the facepiece.

Also, wearing contact lenses with the facepiece on is considered very hazardous even though they don't prevent a good facepiece seal. There is evidence that contact lenses may become lodged above the eye due to pressure in the facepiece, so they should not be worn.

VII. The Drager BG-174 A

a. Introduction- The Draeger BG 174-A (or 1 74) is a self-contained,closed-circuit breathing apparatus that you carry on back. For a limited time, it supplies you with oxygen and removes carbon dioxide from the air you breathe.

The Draeger breathing apparatus recycles and replenishes the air in a continuous cycle within the apparatus, completely independent of the air around it.

The BG 174-A weighs about 30 pounds, and its working are protected by a carrying frame and metal cover. If you encounter conditions such as low roof or an obstructed pathway during rescue and recovery operations, you can remove the Draeger BG 174-A from your back and push it ahead of you or pull it behind you.

The Draeger apparatus is also equipped with automatic and manually-operated safety devices and other features, including pressure gauges to let you know how much oxygen you have.

Once the oxygen cylinder is opened, the unit functions by itself, so aside from checking the pressure gauge now and then, you can concentrate on your work.

b. Where You Wear it- The fact that the Draeger apparatus is independent of surrounding air makes it particularly well-suited for mine rescue and recovery work after fires and explosions, where you may encounter smoke, toxic or poisonous gases, fumes, or other conditions that make the air around you unfit to breathe.

The apparatus will not offer protection against poisonous gases absorbed through your skin such as hydrocyanic acid.

Because the BG 174-A can provide you with up to 4 hours of breathing protection. the apparatus is especially good for underground work or in other situations where it may be hard to determine exactly how much time you will need in order to complete your work.

c. How it Works- Basically, the BG 174-A breathing apparatus works like this: When you inhale, oxygen from the oxygen bottle flows through the breathing bag ,and travels up the inhalation tube to you. When you breathe out; the exhaled air passes into a regenerative canister where chemicals remove carbon dioxide, a by-product of the breathing process. Then it's passed along to the breathing bag in the middle of the unit where it's mixed with free oxygen and the whole process begins again. The oxygen you use up when you breathe is replaced from an oxygen cylinder at the rate of I.5 liters per minute. This is known as "constant flow" metering. If you use up oxygen at a faster rate, a lung demand valve built into the apparatus responds by letting more oxygen into the system.

d. Oxygen Cylinder- Once the cover is removed. you can easily see the unit's oxygen cylinder. which is fitted horizontally to the bottom of the frame.

The BG 174-A's cylinder is made or strong alloyed steel. It has a capacity of 2 liters, which is roughly equivalent to 2 quarts. At full pressure the cylinder can contain up to 440 liters of compressed oxygen.

The cylinder must be tested every 5 years to see that it remains in good condition.

Just opposite the connection that joins the cylinder to the unit is the cylinder valve which is used to open and close the cylinder. This valve has a special "slip clutch" design which helps keep you from opening or closing it accidentally. To open the cylinder valve, pull out on it and with two fingers, gently turn it counterclockwise until it's all the way open, then turn it back about a half turn. Turning it back half a turn leaves some "play" in the valve so that when you're wearing the apparatus you can reach back and assure yourself that the valve is open.

When you close the valve, again pull it out and with two fingers only. Turn it clockwise until the valve is closed.

The "two-finger" method is recommended because twisting the valve too hard can strip or otherwise damage the threads on the valve seat's spindle.

On the top of your oxygen cylinder is a safety device known as the pressure burst cap.

When the pressure within the cylinder reaches 4450 PSI, the cap will "burst," allowing oxygen to escape through holes in it. This keeps the bottle from rupturing with great force. Heat can cause the cylinder to approach the 4450 PSI "danger limit."

At 2000 PSI, it takes approximately 700' F to make the oxygen within the cylinder expand to 4450 PSI. causing the cap to burst. With a full. four-hour cylinder - 3135 PSI-it takes approximately 300o F to do the same thing .

e. Oxygen Control Group- On the right side of the unit's carrying frame are a number of parts which together make up the oxygen control group. These are the parts that control (or regulate) the oxygen supply as it comes from the cylinder.

The oxygen control group is connected to the oxygen cylinder by a threaded, finger-tight connection, and to the breathing system by way of the preflush/dosage line.

Parts included in the oxygen control group are: the pressure reducer, the dosage metering orifice, the preflush unit, the pressure gauge shutoff valve, and the bypass valve.

f. Pressure Reducer- The pressure reducer is located in the center of the oxygen control group.

The adjustment nut for the pressure reducer is located inside the sealed blue knob-like housing you'll see in the oxygen control group. As its name indicates, this part reduces the pressure of oxygen coming from your cylinder to a more manageable 57 PSI.

g. Dosage Metering Orifice- This oxygen then flows through the dosage metering orifice, a drilled orifice (hole) which meters it to deliver a "constant flow" of about 1.4 to 1.7 liters per minute to the breathing bag. This enough oxygen to sustain you while you're working at a moderate rate. By contrast, while you're sitting in this room, you use up, about eight-tenths (.8) liters per minute.

h. Preflush Unit- Within the housing with a black rubber cover are parts designed to flush the breathing bag with 6 to 7 liters of pure oxygen immediately after the cylinder is opened. The parts within this housing are known as the preflushing unit.

Automatically prefushing the breathing bag serves two purposes: It gets rid of any residual air that might have accumulated in the bag, and it makes the apparatus immediately ready for use in an emergency.

i. Pressure Gauge Shutoff Valve- The parts of the oxygen control group that we'll be talking about next-the pressure gauge shutoff valve and the manual bypass valve-are very important ones. Hopefully, you'll never have to use them. These are "back up" safety devices designed to be used in an emergency. The pressure gauge shutoff valve is the metal lever located between the pressure reducer and the preflush unit. You should close this valve only if you suspect your pressure gauge or pressure gauge line is leaking. (This is usually indicated by a sharp, quick drop in your chest gauge reading or the premature sounding of the warning whistle.)

To activate the pressure gauge shutoff valve, lift the lever approximately 30 to 45 degrees from the horizontal to the stopping point. Lifting the lever shuts off oxygen from your pressure gauge line and warning whistle. It does not affect the constant dosage or the medium-pressure oxygen going to your lung demand valve. Once you've lifted the lever, keep an eye on your chest gauge so you can tell if there's a leak in the gauge or gauge line. If there is a leak, oxygen trapped in the line will escape, making the pressure gauge reading fall quickly. and when the pressure reaches 20 to 25 percent of full cylinder pressure, your warning whistle will sound for 20 to 60 seconds.

These two factors-complete loss of gauge line pressure and the brief sounding of the warning whistle-prove that there is a leak, the pressure gauge line is severed, or the gauge is malfunctioning, so leave the shutoff lever in the "up" position.

However, if your pressure gauge reading does not drop and gas trapped in the line keeps the gauge "frozen" at the pressure you read when you first lifted the shutoff lever, you'll know there is no leak in the pressure gauge line. If that's the case, be sure and put the shutoff lever back down in its original position.

This is important for two reasons:

(1) If you don't push the lever back down, your chest gauge will continue to indicate how much pressure you had when you lifted the shutoff lever rather than what's actually in the cylinder.

(2) If your pressure gauge shutoff lever is in the "up" position your warning whistle is isolated. so it cannot sound to let you know when your oxygen is low.

j. Bypass Valve- The second of the two safety features located within the oxygen control group is a black recessed button surrounded by a red rim-the manual bypass.

Like the pressure gauge shutoff valve, the manual bypass is for emergency use only.

It is called a "bypass" valve because pushing it sends oxygen directly from the cylinder to you, hence "bypassing" the parts of the apparatus that limit or control its pressure. Use this bypass valve only if your oxygen control malfunctions and you're not getting the required 1.5 liters of oxygen per minute. To activate the bypass valve, you need only press it for an instant and then release it. The valve is self-closing.

Because it bypasses elements within the system that control oxygen supply, this valve can deliver up to 50 liters of oxygen per minute to the breathing bag. That's far more than you need so use it sparingly.

You should also keep in mind that since the oxygen is coming directly to you from the cylinder, you'll use up what's in your cylinder much faster. That means you'll have far less time under oxygen. Never use the bypass valve to "freshen" or "cool" the oxygen in the breathing bag. That's simply a waste of oxygen.

Remember to use the manual bypass only when it is absolutely necessary-and when you do, use it sparingly.

k. Pressure Gauges- A pressure gauge is an instrument which measures the amount/pressure of oxygen in your cylinder. The BG 174-A has two of them-a chest gauge and a cylinder gauge. They are marked in increments of 200 PSI and are luminous so you can see them in the dark, or in other conditions that limit visibility.

These two gauges, though they both give the oxygen pressure reading, work independently of each other.

1. Chest Gauge- The chest pressure gauge operates only when the oxygen valve is open. It measures the oxygen pressure going into the apparatus from the cylinder. This gauge is located at the end of the high-pressure line extending from the oxygen control assembly and warning whistle.

The chest gauge is the one you'll refer to when you're actually wearing your Draeger apparatus. It is fastened to the right side of the harness by a rubber strap so it's always within easy reach. When not in use, the chest gauge is protected by a metal cover.

After checking the pressure, the gauge should always be put back into its cover. This holds the gauge and protects it from external damage.

Leading from the unit to the chest gauge is a rubber coated pressure gauge line. Inside the tube's rubber coating is a closely wound spiral high-tension line which is relieved of tension by a bronze core. Remember that if this tube develops a leak, you can lift the pressure gauge shutoff lever to keep oxygen from flowing into it.

2. Cylinder Gauge- The cylinder pressure gauge is attached to the top of the oxygen cylinder. It gives a constant reading of the pressure, whether the cylinder is in storage or in the apparatus. This is the gauge you'll refer to when you fill your cylinder or add a new one. When the unit is in use, the cylinder gauge is not visible because it is under the unit's cover.

l. Warning Whistle- Connected to the pressure gauge line assembly above the oxygen control group is a whistle called the warning whistle. It is designed to warn you when you have only 20 to 25 percent of the original charged pressure left in your cylinder.

It will also alert you to a leak in the high-pressure line leading to the chest gauge. When the pressure reaches the point where the whistle sounds, the leak can be stopped by lifting the pressure gauge shutoff lever.

When the warning whistle sounds, it blows for about 20 to 60 seconds and uses about 3 liters of oxygen.

When you hear this whistle, you'll know you have approximately 90 liters of oxygen remaining or about 45 to 60 minutes worth of oxygen.

The whistle will sound at about 700 PSI on a 4-hour apparatus, and at 600 PSI on a 3-hour apparatus.

m. Breathing Bag- The breathing bag is located at the center of the unit, protected on all sides by the carrying frame. It is made of a synthetic 3-ply rubber fabric and has a volume of 5 to 7 liters.

The breathing bag has two "sockets" on it. One of these is a threaded socket which connects to the lung demand assembly, and the other elbow socket connects to the regenerative canister. By unscrewing these sockets and the preflush/dosage line, you can remove the breathing bag for cleaning and disinfecting.

n. Regenerative Canister- The metal unit at the top of the apparatus is called the regenerative canister. The special chemicals inside the regenerative canister absorb the carbon dioxide from the air that is exhaled by the wearer. The oxygen in the exhaled air is not affected by the chemicals. It passes through the canister and goes back into the breathing bag where it can be breathed again.

There are two types of canisters you can use with the Draeger apparatus:

1. Refillable training canister.

2. Factory-packed. disposable canister (sometimes referred to as an alkali canister).

The basic difference between the two is that the factory- packed. disposable canister is the only one approved for actual rescue work.

Both canisters have arrows on them The match up to the arrows on the canister holder at the top of the apparatus.

1. Refillable Training Canister- The refillable training canister is approved for training purposes only and has a maximum period of 4 hours use. It is made of stainless steel and can be used over and over again as long as the absorbent chemicals are freshly packed for each use.

Inside the canister is a set of baffles designed to expose more surface area of the chemicals to the exhaled air. The canister must be completely filled each time it is used in order to get good results. You will learn the proper procedure for filling the canister later on in the lecture.

The chemicals used to fill the canister have a shelf life of approximately 2 years from the date of manufacture which is printed on the packaging label. For easy reference, the expiration date for the chemical is also printed on the label.

2. Factory Packed Rescue Canister- The factory packed cannister is similar to the refillable. However, the chemical is higher in concentration to remove virtually all the carbon dioxide from the breathing circuit, and has breathing channels or baffles in which the exhaled air has to travel to be properly cleaned.

It has a expiation date on the label, and string seals or tape seals to insure that the unit has not been used before.

o. Diaphragm- These parts depend for their operation on a very important part of the lung demand assembly-the diaphragm. This is how it works:

This diaphragm moves in or out in response to pressure created by the breathing bag. When the breathing bag has too much oxygen in it, it becomes overinflated and so produces a forward pushing pressure or "positive pressure" against the diaphragm.

On the other hand, when the bag has less than the normal amount of oxygen in it, it becomes deflated, pulling the diaphragm in toward it. this pulling motion is known as "negative pressure."

p. Pressure Relief Valve- The pressure relief valve is the part of the lung demand assembly that keeps oxygen from building up in the breathing bag if yyou use less than the unit provides. For example, if you're resting, you probably won't consume as much as 1.4 to I.7 liters per minute of oxygen.

The excess oxygen will then fill the breathing bag to the point where it becomes overinflated. The overinflated bag creates positive pressure which pushes against the diaphragm. causing it to move outward against a spring.

As the diaphragm moves outward, it moves away from the sealing bolt, revealing an opening in the diaphragm that normally remains closed. The excess air flows through this opening, escaping to the outside atmosphere thorough a nonreturn valve.

q. Lung Demand Valve- The lung demand valve is the part of the lung demand assembly that automatically lets more oxygen into the circuit if you require more than what's flowing into the breathing bag.

If you are working hard, for example, the amount of oxygen you need may be greater than the 1.4 to 1.7 liters per minute your unit normally supplies. When this happens, the breathing bag deflates with each breath you take until it no longer supplies you with enough oxygen. This is where the lung demand valve comes in.

As the base deflates, negative pressure pulls on the diaphragm. This forces the plunger in the diaphragm to move inward against the valve's stickpin-type lever. The lever in turn opens the valve, allowing oxygen (at 57 PSI) to now directly from the pressure reducer to the lung demand assembly by way of the medium-pressure oxygen

line. This oxygen flows into the circuit at a rate of 80 to 120 LPM.

r. Inhalation and Exhalation Valves In a closed-circuit breathing apparatus, keep in mind that it is very important that the breathing air flows only in one direction. If it didn't, you'd risk breathing in exhaled air filled with carbon dioxide, or fresh oxygen might not get to you. In the Draeger apparatus, the inhalation and exhalation valves keep the air flowing in one direction.

During inhalation the air is drawn out of the breathing bag through the lung demand assembly. The air then passes through the inhalation valve near the bottom left side of the lung demand assembly. When the air is exhaled by the wearer, it passes through the exhalation valve located on the top of the lung demand assembly.

Remember, these are one-way valves designed to control the direction of air flow in the breathing system.

s. Breathing Hoses- The breathing hoses used with the Panorama Nova face-piece are made of durable, corrugated rubber. They are very flexible and offer little resistance to inhaled and exhaled air, enabling you to breathe almost as freely as in open air.

The hoses consist of an inhalation hose and an exhalation hose. The inhalation hose has a saliva trap attached to it.

The trap is on the inhalation hose because it must be located on the lowest part of the apparatus when it is worn so that the moisture will settle there. The trap features a chain connection between the trap and its cap, so that the cap cannot be misplaced when it is removed.

The hoses, like the facepiece, have a single coupling assembly (for attachment to the facepiece) with a divider to channel the breathing air. There is also a small dam inside to prevent excess saliva from going into the exhalation hose.

At the other-end of the hoses are two threaded connections for attachment to the apparatus. The inhalation hose (with the saliva trap) connects to the inhalation hose connection at the lower portion of the lung demand assembly.

The exhalation hose connects to the exhalation hose connection near the top of the lung demand assembly.

t. Facepiece- The Panorama Nova is the facepiece used with the BG 174-A. It has a single "panorama" type lens which offers 90 percent peripheral vision, allowing you to see most of what you normally see. It permits unobstructed vision with both eyes, which is very important in judging distances.

The mask has a double-sealing edge for protection against the infiltration of smoke and gases. The Nova facepiece also has a nosecup inside the mask designed to help channel the inhaled and exhaled air to and from the wearer.

This nosecup acts as the third sealing edge to protect you from smoke and gases.

The Nova facepiece has a five-stamp head harness, which adjusts to provide a good facepiece seal, and a neck strap which you can put around your neck to support the mask when you are not wearing it. The neck strap can be shortened from its regular length so you can carry the facepiece close to your chest when you are not under oxygen.

It is shortened by attaching the button which is located on the strap, to the small buttonhole on the center head strap.

At the lower part of the facepiece is a single coupling assembly where the breathing hoses are attached. You will notice when you look closely that facepiece connection, that it has divider or ridge built into it. This divider helps to separate the inhaled air from the exhaled air as it passes between the hoses and the wearer.

u. Cover- The cover of the Draeger self-contained breathing apparatus acts as a protective shell for its internal parts. It is made of a lightweight yet rugged metal that will withstand heavy wear and tear.

The cover is specially designed to be slim so that it will fit into tight spots. Sled-like ridges on the cover make it easy to slide the apparatus ahead of you or pull it behind you. Most Drager units in use have covers made of an aluminum alloy. Newer models have covers made of stainless steel.

The aluminum alloy cover has a stripe of high-visibility orange paint and two strips of reflective tape down the center which make it easy to spot the wearer in darkness, fog, smoke, or other conditions that limit visibility. The stainless steel cover has two red reflectors on the lower part of the cover near the fasteners.

On the top right center of the cover is the approval label. It is here that you will and what the approved service time is for the apparatus, the approval number, and the minimum use temperature.

In order to get at the units internal parts, you must first remove the cover. to do this, push in on the step fasteners on the lower part of the cover.

When the fasteners release, pull upward and outward on the cover until the tab on top slips out of the slot.

To close it, simply put the top tab into its slot and push the bottom of the cover down over the fasteners until you hear it "snap" into place.

v. Wearing Harness- The wearing harness consists of two adjustable shoulder straps with double slide buckles and a waist belt.

The shoulder straps have plastic rings on the ends that, when pulled down, adjust the straps for proper fit. The double slide buckles are designed for quick release.

The right shoulder strap is equipped with a tension relieve strap. There is a springhook on this strap which clips to the breathing hoses to relieve some of the hoses' weight from your facepiece.

0x01 graphic

VIII. The Drager BG-174 a, RZ testing procedures

a. Exhalation Valve Test- First, zero-adjust the tester by turning the block adjustment knob in the lower left-hand corner of the tester. After this initial adjustment, do not readjust this setting for the rest of the testing.

Remove the cover from the tester's hose connection and screw in the breathing hose adapter, followed by the breathing hoses. This connection should be tight enough to prevent leakage.

To test the exhalation valve: Cap off the exhalation hose and connect the inhalation hose (the one with the saliva trap) to the exhalation valve assembly on the apparatus.

Set the tester in negative pressure pumping and start to work the bellows by pumping with very gentle strokes (you should meet resistance at once). Watch the breathing bag. It should not begin to deflate after 5 seconds, indicating the exhalation valve is working properly: it only allows the wearer's exhaled air to pass into the apparatus-not back out of the apparatus.

b. Inhalation Valve Test- Now to test the inhalation valve: Remove the hose from the exhalation valve, and connect it to the inhalation valve, making sure to position the hose so that the saliva trap is in a vertical position before tightening the connection. This will ensure that the trap is in the proper position when you put on the apparatus.

Switch the selector knob to positive pressure pumping and gently pump. Again watch the breathing bag. It should not begin to inflate after 5 seconds, indicating the inhalation valve is working properly; it only allows the wearer to inhale air from the breathing bag, and not exhale it back into the bag.

c. Positive Pressure Leak Test- Now you are ready to test for air leaking out of the apparatus.

First, sent the relief valve vent (in the lung demand assembly) with the rubber plug provided in the tool kit. Then plug the opening in the warning whistle with the cover, also included in the tool kit.

Now, the tester should already be set on positive pressure pumping. so pump up the

breathing bag until the meter needle reads +100 mm H2O (+10 mbar).

Then switch the tester to leak test, and bleed the needle down to +70 mm H2O (+7 mbar).

Start the stopwatch and observe the needle for 60 seconds. The needle should not drop more than 10 mm H20 (1 mbar).

d. Negative Pressure Leak Test- Now, to check for air leaking into the apparatus, including through the relief valve: Remove the rubber plug from the relief valve vent only. Don't remove the whistle cover.

Switch the tester to negative pressure pumping and pump the bellows until the meter reads -100 mm H20 (-10 mbar).

Then switch the tester to leak test and bleed the needle up to -70 mm H20 (-7 mbar).

Start the stopwatch and observe the needle for 60 seconds. After 60 seconds, the needle should not rise more than 10 mm H20 (1 mbar).

e. Preflush /Pressure Gauge Equalization Test- First, remove the cover from the warning whistle.

Then set the tester on negative pressure pumping and open the oxygen cylinder valve by placing two fingers on the knob, pulling it out and rotating it counterclockwise. Open the valve fully, then turn it back one-half turn, the method you should always use when you turn on the apparatus.

The breathing bag should completely inflate due to the preflushing action, and there should sound a short chirp of the warning whistle.

When the preflushing is complete, observe the chest pressure gauge to ensure that it reads within 10 percent of the reading on the oxygen cylinder gauge.

f. Relief Valve Test- You can now check the opening pressure of the relief valve To do this test, open cylinder valve (with tester set on negative pressure pumping and leak test).

The flow of oxygen from constant dosage will cause relief valve to open, with opening pressure indicated on the tester gauge. The valve should open between +10 and +40

H2O(+ 1 and +4 mbar).

g. Lung Demand Valve/Breathing Bag Volume Test- Now that the bag is full, you will be pumping the air out of the bag to figure out: (1) how many liters the bag holds, and (2) how much negative pressure is required before the demand valve kicks in. You can figure out both by pumping the air out of the bag, counting the strokes, and listening.

h. Bypass/Constant Dosage Test- Now that the breathing bag is deflated, you can check to see if the manual bypass valve works to fill the bag in 10 seconds or less. Then you'll be checking to see how much oxygen is metered into the bag when the apparatus is functioning automatically.

Set the tester on the "red" dosage test (0.5 to 2 LPM).

Again put the plug in the vent of the pressure relief valve.

Press and hold the red bypass valve and listen for the flow of oxygen into the breathing bag as the bag fills up.

Release the bypass button when the needle reads 1.7 LPM on the outside red scale. The needle should then settle somewhere. between 1.4 and 1.7 LPM, indicating that the dosage device is allowing approximately 1.5 LPM of oxygen to constantly flow into the breathing bag.

i. Whistle Activation Test- First, remove the plug from the relief valve vent.

What you are going to do now is check to see that the warning whistle sounds when it is supposed to sound.

Remember, the whistle is designed to alert the wearer when the oxygen in the cylinder is down to 20 to 25 percent of the original cylinder pressure.

In testing the warning device, you should first close the oxygen cylinder valve by placing two fingers on the knob, pulling it out, and rotating it clockwise until you meet resistance. Do not overtighten the valve. Then check the pressure on the chest pressure gauge. It should move towards zero; and the whistle should sound when the needle reads 20 to 25 percent of the full cylinder pressure.

j. Whistle Duration/Pressure Gauge Shutoff Test- Now that you've tested the whistle to determine when it sounds, you'll want to determine how long it sounds. Remember it should sound for 20 to 60 seconds.

At the same time, you will be testing the pressure gauge shutoff valve to see that it closes properly.

Before you begin this test, switch the tester to negative pressure pumping.

To get the whistle to sound, lift the pressure gauge shutoff lever, open the oxygen cylinder valve (again with two fingers) and start the stopwatch. The whistle should sound for 20 to 60 seconds.

Now check the chest pressure gauge. It should read zero, indicating that the shutoff lever properly closes the line leading to the gauge.

When you're finished with the test, make sure to return the shutoff lever to its original position.

k. High and Medium Pressure Leak Test- Now you're finished using the tester and are ready for the final test: testing the high and medium-pressure lines for leaks if the tester has indicated that a leak exists.

With the cylinder valve still open, coat the high- and medium-pressure lines and connections with a soap lather or a leak detector solution, and look for bubbling of the solution. Where there are bubbles. there is a leak.

There is also another way of testing for high-pressure leaks: Turn on the apparatus and plug the preflush/dosage line with a special plug (R1/4"). After the preflush is complete, shut off the cylinder valve and tap on the test gauge with your finger.

After 5 minutes, open the cylinder valve again and observe the test gauge for any noticeable movement of the needle. If the needle jumps up, this would indicate that oxygen leaked out during the 5-minute period.

That concludes the testing. You can now close the cylinder valve, unless you are going directly into training or rescue operations.

Section 2

Mine Gases

Introduction
Basics of gas detection

Gas detection
Gas detection requirements
Portable gas detectors
Air sampling and chemical analysis

Basic gas principles

Description
Diffusion of gases
Atmospheric pressure
Temperature
Specific gravity
Explosive range
Solubility

Health hazards

toxic gases
asphyxiating gases

Measurements of gases

TLV
Ceiling limit
IDLH
PPM

Mine gases and their components

Air
Oxygen
Methane
Heavy Hydrocarbons
Acetylene
Hydrogen
Nitrogen
Carbon Dioxide
Carbon Monoxide
Hydrogen Sulfide
Nitrogen Dioxide
Sulfur Dioxide
Smoke
Mine Damps

I. Introduction

Under normal conditions, many gases are present in the mine. The mine's ventilation system is designed to bring in fresh air to disperse and remove harmful gases and to supply oxygen.

But during a disaster, the situation may be quite different. Fires and explosions may release dangerous gases into the atmosphere. And a disrupted ventilation system could result in an oxygen-deficient atmosphere and/or a buildup of toxic or explosive gases.

II. Basics of Gas Detection

a. Gas Detection- Gas detection is an important part of any rescue or recovery operation. Your team will make frequent tests for gases as it advances inby the fresh air base. For your own safety, you'll want to know what harmful gases are present, how much oxygen is in the atmosphere, and whether or not gas levels are within the explosive range.

Knowing what gases are present and in what concentrations provides you with important clues as to what has happened in the mine. Test results can also give you an idea about existing conditions. For example, if you get carbon monoxide (CO) readings, that indicates there's probably a fire. The amount of carbon monoxide indicates something about the extent of that fire.

b. Gas Detector Requirements- Each mine rescue station is required by law to have gas detectors appropriate for detecting each type of gas that may be encountered in the mine, and two oxygen detectors.

c. Portable Gas Detectors- The type of gas detection equipment most often used by mine rescue teams is the portable gas detector. Portable gas detectors include such devices as methane monitors, carbon monoxide (CO) detectors, and the multi-gas detectors used in conjunction with various tubes. The team uses these devices to test the mine air repeatedly as it advances inby the fresh air base.

d. Air Sampling and Chemical Analysis- Another way to test for gases is to collect air samples, special syringes, evacuated bottles, (bottles from which air has been removed), or gas or liquid displacement containers. These samples are then sent to a laboratory for chemical analysis. Chemical analysis is also sometimes performed at the mine site with portable equipment.

Chemical analysis is generally a more time-consuming process than testing with a portable device, but its advantage is accuracy. A chemical analysis tells exactly what gases the sample contains, and in precisely what amounts.

A complete chemical analysis can also reveal the presence of gases that portable detectors are not designed to detect.

Air samples aren't taken as often as portable detector readings, but they are still an important part of rescue and recovery operations. For example, you may be required take air samples from ventilation shafts and return airways

This method is often used to get information about existing conditions prior to sending teams underground.

Air samples taken from behind sealed areas of the mine are analyzed to determine when it's safe to begin recovery work.

III. Basic Gas Principles

In order to test for gases and to understand what the test readings mean, you should first know a little about the characteristics and properties of gases. After we've discussed these general principles, we'll talk about specific gases you might encounter during rescue and recovery work.

a. Description- To help you understand what a gas is, let's compare it with a liquid and a solid. A solid has a definite shape and volume. A liquid has a definite volume, but changes shape according to the shape of its container.

However, a gas is a substance with neither a definite shape nor volume. It expands or contracts to fill the area in which it's contained.

b. Diffusion of Gases- The volume of a gas changes in response to any change in atmospheric pressure or temperature. For example:

An increase in pressure causes a gas to contract.
A decrease in pressure causes a gas to expand.
An increase in temperature causes a gas to expand.
A decrease in temperature causes a gas to contract.

The ventilating air currents in the mine also affect the gas's rate of diffusion. The rate of diffusion is greatly increased by higher velocities of air currents or by turbulence in the air.

Knowing the effects of air current, temperature, and pressure on a gas will help you determine its rate of diffusion. The rate of diffusion is how quickly the gas will be quickly mix or blend with one or more other gases and ho it can be dispersed.

c. Atmospheric Pressure and Its Effects on Rate of Diffusion- Pressure exerted on a gas is usually atmospheric pressure. Atmospheric pressure is measured on a barometer. A rise in the barometric reading indicates an increase in pressure. A drop in barometric reading indicates a decrease in pressure. The atmospheric pressure varies within a mine, just as it does on the surface.

Atmospheric pressure affects the diffusion rate of a gas. For example, if the barometer rises, indicating increased pressure, gas responds by contracting.

A gas that 9 s squeezed into a smaller area like this is more concentrated, so it diffuses more slowly. As you might guess, it's much easier for concentrations of explosive gases to build up when the barometric pressure is high. And it is harder to disperse the gases by means of the mine's ventilation system.

On the other hand, when barometric pressure falls, the pressure on the gas is reduced. The gas responds by expanding. Once the gas expands, it is less concentrated, so it diffuses more quickly.

d. Temperature and Its Effects on Rate of Diffusion- Under normal conditions, the temperature in a mine does not vary greatly, but fires and explosions will produce temperature variations. This is why it's important for you to know what happens to gases when temperatures change.

High temperatures (or heat) cause gases to expand, so they diffuse more quickly. Consequently, heat from a fire in the mine will cause oases to expand and be dispersed more easily.

Lower temperatures work the opposite way: Gases respond to cold by contracting and by diffusing more slowly.

e. Specific Gravity or Relative Weight- Specific gravity is the weight of a gas compared to an equal volume of normal air under the same temperature and pressure. (This is also referred to as "relative weight.")

The specific gravity of normal air is 1.0. The weight of air acts as a reference point from which we measure the relative weight of other gases. For example, a gas that is heavier than air has a specific gravity higher than 1.0. A gas that is lighter than air will have a specific gravity less than 1.0.

If you know the specific gravity of a gas, you will know where it will be located in the mine and where you should test for it.

Gases issuing into still air without mixing tend to stratify according to the gas's specific gravity. Light gases or mixtures tend to stratify against the roof and heavy gases or mixtures tend to stratify along the floor.

Methane, for example, has a specific gravity of 0.5545. This is lighter than normal air. Knowing this, you can predict that methane will rise and collect in greater concentrations near the top or roof of a mine. This is why you test for methane near the top.

If the weight of a gas you're testing for is heavier than normal air, you'll know to test for it near the bottom of the mine or in low places. That's because heavier gases tend to fall, so you can expect to find them in greater concentrations in low areas.

Besides helping you determine where to test for a gas, specific gravity also indicates how quickly the gas will diffuse and how easily it can be dispersed by ventilation.

In stir air, the ordinary process of diffusion is a very slow process. However, under usual mine conditions, ventilating air currents and convection currents produced by temperature differences cause a rapid mechanical mixing of gases with air. And once the gases are mixed they will not separate or stratify again.

Light gases, such as methane or hydrogen, diffuse rapidly and are fairly easy to disperse. Heavier gases such as carbon dioxide don't diffuse rapidly, so they're more difficult to disperse. It's much easier to remove a concentration of a light gas like methane by ventilation than it is to remove the same concentration of a heavier gas like carbon dioxide. Specific gravity is not the only factor that determines how quickly a gas will diffuse or disperse. Temperature and pressure also affect it.

Remember that an increase in temperature makes a gas diffuse more rapidly. A decrease in temperature slows down the rate of diffusion.

Atmospheric pressure works just the opposite: An increase in pressure slows down the rate of diffusion. A decrease in pressure speeds it up.

f. Explosive Range and Flammability- A gas that will bum is said to be "flammable." Any flammable gas can explode under certain conditions. In order for a flammable gas to explode, there must be enough of the gas in the air, enough oxygen, and a source of ignition. The range of concentrations within which a gas will explode are known as its "explosive range." Figures representing the higher and lower limits of the explosive range are expressed in percentages.

The amount of oxygen that must be present for an explosion to occur is also expressed as a percentage. When the necessary oxygen concentration approaches that found in normal air, the level is expressed simply as "normal air."

The explosive range of methane, for example, is 5 to 15 percent in the presence of at least 12.1 percent oxygen.

g. Solubility- Solubility is the ability of a gas to be dissolved in water. Some gases found in mines are soluble and can be released from water. Sulfur dioxide and hydrogen sulfide, for example, are water-soluble gases. Both may be released from water.

Solubility is an important factor to consider during recovery operations. When a mine is sealed off for any length of time, water can collect in it. This water may have occurred naturally, or it may have been introduced during firefighting.

Whatever the case, pools of water can release water-soluble gases into the air when they are stirred up. Pumping water from such pools, or wading through them, can release large amounts of soluble gases- which would not otherwise be found in the mine atmosphere.

h. Color /Odor/Taste- Color, odor, and taste are physical properties that can help you identify a gas, especially during barefaced exploration. Hydrogen sulfide, for example, has a distinctive "rotten egg" odor. Some gases may taste bitter or acid; others sweet. The odor of blasting powder fumes, together with a reddish-brown color, indicates there are oxides of nitrogen present.

Of course, you can't rely on only your senses to positively identify a gas. Only detectors and chemical analysis can do that. And many hazardous gases, such as methane, have no odor, color, or taste. But keep these properties in mind as we discuss each gas you may encounter in the mine. One or more of these properties may be your first clue that a particular gas is present.

IV. Health Hazards

a. Toxic Gases- Some gases found in mines are toxic (poisonous). This can refer either to what happens when you breathe the gas, or what happens when the gas comes into contact with exposed areas of your body.

The degree to which a toxic gas will affect you depends on three factors:

how concentrated the gas is,
how toxic (poisonous) the gas is, and
how long you're exposed to the gas.

Some toxic gases are harmful to inhale. A self-contained breathing apparatus (SCBA) will protect you from such gases, as long as your face-to-facepiece seal is tight. Other toxic gases harm the skin, or can be absorbed by the skin. As you might guess, an SCBA won't protect you from such gases. If you wear your SCBA in petroleum-based fumes for prolonged or successive periods, the fumes can eventually permeate its rubber parts so that the apparatus no longer provides you with adequate protection. Your team may be forced to leave an area where such gases are detected.

b. Asphyxiating Gases- "Asphyxiate" means to suffocate or choke. Asphyxiating gases cause suffocation. They do this by displacing oxygen in the air, thus producing an oxygen-deficient atmosphere. Since your self-contained breathing apparatus supplies you with oxygen, it will protect you against asphyxiating gases.

V. Measurement of Gases

a. Threshold Limit Value (TLV)- The amount of a gas exposure for an 8 hour day for 5 days a week without any harmful effects.

b. Ceiling Limit- The amount of gas at no time a person can be exposed to.

c. Immediately dangerous to life or health (IDLH)- The maximum concentration of a gas, in case of SCBA failure, one could escape without any irreversible health effects.

d. Parts Per Million (PPM)- The most accurate measurement of a contaminant in the atmosphere.

PERCENT PPM

1.0........................................10,000

.1.........................................1,000

.01..........................................100

.001..........................................10

.0001..........................................1

VI. Mine Gases & Their Components

a. Air

Chemical Formula: None

Specific Gravity: 1.000

Source: Atmosphere

Characteristics: No color, odor, or taste

Pure dry air at sea level contains the following:

Oxygen .......................... 20.94 %

Nitrogen ........................ 78.09 %

Argon ........................... 0.94%

Carbon Dioxide .................. 0.03%

b. Oxygen

Chemical Formula: O2

Specific Gravity: 1.105

Oxygen will not burn or explode

Source: Atmosphere

Characteristics: No color, odor or taste

Note: When another gas is introduced into the atmosphere of artificial environment, such as a mine, tunnel or man holes, oxygen is usually displaced causing asphyxiation.

Oxygen present Effect on Body

21% Breathing Easiest

19.5% Minimum required by law

17% Breathing faster & deeper

16.25% Minimum required by law

15% Dizziness, buzzing noise, rapid pulse, headache, blurred vision

9% Unconsciousness

6% Breathing stops, cardiac arrest

c. Methane

Chemical Formula: CH4

Specific gravity: 0.555

Needs 12.5% O2 to ignite

Explosive Range: 5-15%

Ignition Temperature: 1100o-1300o F

Source: Carbon products decaying in anoxic environment

Characteristics: No color, odor or taste

d. Heavy Hydrocarbons (LEL)

Ethane Propane Butane

C2H6 C3H8 C4H10

1.05 1.56 2.01

3.0-12.5% 2.12-9.35% 1.86-8.41%

All have a "gassy" odor

e. Acetylene

Chemical Formula: C2H2

Specific Gravity: 0.9107

Explosive Range: 2.4-83%

Ignition Temperature: 581oF

Source: Methane heated in a low oxygen atmosphere, Calcium carbide mixed with water

f. Hydrogen

Chemical Formula: H2

Specific Gravity: 0.0695

Needs 5% oxygen to ignite

Explosive Range: 4.1-74%

Ignition temperature: 1030o - 1130oF

Source: Water on super hot fires, battery charging

g. Nitrogen

Chemical formula: N2

Specific Gravity: 0.967

Ceiling Limit: 810,000 ppm

Source: Atmosphere, released from coal seam

Characteristics: No color, odor, or taste

h. Carbon Dioxide

Chemical Formula: CO2

Specific Gravity: 1.529

Ceiling Limit: 1.5%

IDLH: 50,000 ppm

Source: Product of complete combustion, slow oxidation of carbon products

Characteristics: No color or odor, acidic taste above 10%

I. Carbon Monoxide

Chemical Formula: CO

Specific Gravity: 0.967

Needs 6% O2 to ignite

Ignition Temperature: 1100oF

Explosive Range: 12.5-74%

TLV: 50 ppm

Ceiling Limit: 200 ppm

IDLH: 1500 ppm

Source: Incomplete combustion, diesels, gasoline engines

Characteristics: No color, odor, or taste

Effect on the body: 300 times more attracted to hemoglobin than oxygen, forms carboxyhemoglobin which prevents oxidation of cells

j. Hydrogen Sulfide

Chemical Formula: H2S

Specific Gravity: 1.191

Ignition Temperature: 700oF

TLV: 10 ppm

Ceiling limit: 15 ppm

IDLH: 300 ppm

Source: Sulfur dissolving in water in a poorly ventilated area

Characteristics: Colorless, sweet taste, rotten egg smell

Effect on the body: Paralysis of respiratory system

k. Nitrogen Dioxide

Chemical Formula: NO2

Specific Gravity: 1.589

TLV: 1 ppm

Ceiling Limit: 3 ppm

IDLH: 50 ppm

Source: Explosives after-product, diesel exhaust

Characteristics: Burnt powder odor, reddish brown in high concentrations

Effect on the body: Forms nitric acid in lungs causing pulmonary edema

l. Sulfur Dioxide

Chemical Formula: SO2

Specific Gravity: 2.264

Source: Burning of sulfide ores, diesel exhaust, and gob fires

TLV: 5 ppm

Ceiling Limit: 10 ppm

IDLH: 100 ppm

Characteristics: Heavy sulfur odor

Effect on the body: Same as nitrogen dioxide

m. Smoke

Tiny particles of solid and liquid matter suspended in air as a result of combustion

Diesel Particulate Matter

By-products of burning belts

Carbon materials

Usually noxious and toxic gases are present

Can be carcinogen (cancer causing)

n. Mine Damps

The word damp is a derivative of the German word "damf" which means vapor. It was used by the immigrant German miners in the anthracite fields to describe a certain atmosphere condition.

Black damp: Carbon dioxide, nitrogen, and low oxygen.

White damp: Carbon monoxide

Fire damp: Methane

Stink damp: Hydrogen Sulfide

After damp: By-products of a fire or explosion.

Section 3

Surface Organization

Introduction

Notification of a Mine Emergency

Callout procedure
Travel to the emergency
Arrival at Emergency site

Notification Plan

Establishing a Chain of Command

Making surface arrangements

Suggested facilities and arrangements

Command center
Waiting area for teams
Bench area for apparatus
Security
Information center
Waiting area for family and friends
News room for media
Food and sleeping quarters
Laboratory
Medical facilities
Temporary morgue

Suggested personnel and their duties

Mine superintendent
Mine Clerk
Chief electrician
Chief mechanic
Outside foreman

Checkman

Safety Director
Chief engineer
Supply clerk
Lampman
Mine Foreman
Other company personnel

I. Introduction

When an emergency occurs at a mine, the first few hours after the emergency are the most critical and will determine the successfulness mine rescue and recovery operations in saving miners and mine property. How well organized and prepared a mine rescue team is, is critical to any mine rescue and recovery attempt.

Teamwork is essential not only between the mine rescue teams themselves, but also among those on the surface: company administrators, mine personnel, and federal and state officials who comprise an entire rescue network designed to direct and support the tire operation, particularly the rescue teams, during a mine disaster.

Cause of these factors, a chain-of-command must be in place and an emergency notification plan established to designate what necessary personnel must be contacted during a mine emergency.

The time the mine rescue team arrives on-site, rescue and recovery operations will already be underway on the surface. Several officials and mine personnel will have been called to the mine to assume their ties as part of the chain-of-command.

This training manual on surface organization is designed to familiarize the rescue team members on how to organize and manage a rescue and recovery operation, and to understand the role each team plays in relation to the overall organization.

II. Notification of a mine emergency

a. Callout procedure- When an operator is under agreement with the commonwealth, the operator will notify the Bureau of Deep Mine Safety of a related mining emergency.

The bureau then calls each individual mine rescue team member under the covered agreement. The team member should notify his/her employer that he/she is participating in an emergency.

b. Travel to emergency site- Although an emergency is occurring in the mining industry, at no times shall the team member speed or violate Motor Vehicle Codes while enroute to the emergency.

c. Arrival at emergency site- Upon arrival at the scene, the team member shall follow the affected company's policy concerning checking in or reporting to a security station.

Once on company property, attempt to locate the Mine Rescue Vehicle to check in with the state instructors, or if the truck has not yet arrived, check in with the mine office.

III. Notification Plan

All metal and non metal, and surface and underground coal mines are required by law to post a Mine Rescue Notification Plan which instructs what mine rescue team members will be needed to assist in the rescue and recovery operation. This mine Rescue Notification Plan may be part of the Mine Emergency Notification Plan.

Each mine should have an Emergency Notification Plan for notifying necessary personnel when there is an emergency at the mine. This plan lists the various supervisors, administrators, and government officials who must be notified of the mine emergency.

Mine rescue team members are to familiarize themselves with the mine's emergency notification plan which will include the following persons or agencies, their names, addresses, and home and office phone numbers. Those suggested for immediate notification of a mine emergency include:

Mine Superintendent
Mine Foreman
Safety Director
General Mine Manager
General Mine Superintendent
District Inspector (state and federal)
Chief, state department of mines
District MSHA office
District union office
Law enforcement agencies
Medical personnel, ambulances, and other emergency vehicles
Hospital to be alerted

The above list should be tailored to meet individual mine job titles. The mine's emergency organization is a plan of action, designed to restore order at the mine site and supervise emergency efforts. The mine's notification plan could also include other support personnel who would provide services at the mine site. Such persons who may be needed could include: security personnel, police officers, supply clerks, clergy, telephone operators, and coroner.

IV. Establishing a Chain-of-Command

Because many persons will be doing many different jobs during rescue and recovery operations, it is important to establish a clear chain-of-command in order that surface arrangements can be handled smoothly and rescue and recovery work is well-coordinated.

Located at the top of the list of the chain-of-command is the mine superintendent who may delegate the responsibility of other jobs to other reliable company employees. Employees assigned these responsibilities must know in advance exactly what their duties and responsibilities are, who they are to report to, and who in turn, is to report to them. These duties and tasks may be divided.

V. Making Surface Arrangements

a. Suggested Facilities and Arrangements-Surface arrangements cover a wide range of activities and require the coordinated efforts of many persons.

Surface arrangements include such tasks as establishing a command center where all of the decisions are made, providing an adequate information center for releasing information to the public, and for obtaining the necessary supplies and equipment.

1. Command Center- The command center is the most important surface facility and will be the hub of the mine rescue operation. Those in charge will be stationed at the command center to plan and direct the rescue and recovery operation.

The command center will house communications equipment connected to the underground phones and to other surface phone lines. It will contain mine maps to follow the progress of the teams, and to mark findings and plan rescue strategy.

2. Waiting Area for Teams- Another area that is needed is the waiting area for the incoming rescue teams so they have a central location to prepare for rescue operations.

As mine rescue teams arrive at the mine site, they are to check in and be assigned to a team area. If team members carry Mine Rescue Team identification cards, they should present their cards when checking in at the mine site.

The Safety Director, or whoever is in charge of teams, should prepare a rotation schedule for deploying all of the rescue teams who are called to the mine site, and designate which team is to be the exploration team, backup team, and standby team. The rotation schedule is to be posted in the waiting area, and lists each team's status during the rescue or recovery operation.

3. Bench Area for Apparatus- A bench area, where water is available, should be set aside as an apparatus room where the apparatus can be cleaned, tested, and prepared for the benchmen or by the team members themselves. If convenient, the Mine Rescue Station can be used as a bench area for the apparatus.

4. Security- Establishing good security at the mine is essential in order to keep the roads open for mine or emergency personnel, and to ensure that curious bystanders do not hinder rescue efforts or get injured while on mine property. All roads and paths leading to the mine should be secured and guarded by assigned company personnel or police officers.

Incoming traffic on the roads leading to the mine property should be regulated by authorized personnel to keep unnecessary vehicles off the roads and keep these roads open for essential personnel, needed supplies, and emergency vehicles.

State and federal officials will arrive on-site to advise and observe. Federal officials may take charge of the operation if they decide it is necessary, but usually they consult and advise company personnel on the best way to perform rescue and recovery duties.

The rescue team is part of the chain-of-command linkage. The team captain directs and supervises the rescue team, and also deals with the Safety Director or another designated official who is responsible for the rescue teams.

5. Information Center- An area with available space should be established on the surface as an information center. The information center's director will be there to authorize and issue, and have control of the accuracy of the information being released to the public.

The information center's director may be a company official, or could be a federal or state official who is authorized and qualified to answer questions from miners' families or friends, or from the news media. The information center should contain two separate rooms, one to be used as a waiting area for families, and another separate room for the news media.

6. Waiting Area for Families and Friends- The family waiting room should be away from any rescue activity and away from the newsroom. The information center's director should try to periodically inform family members of rescue and recovery operations, and be authorized and qualified to answer questions from miners' families or friends.

7. Newsroom for the Media- The newsroom is the only area where the news media should be given any information. News reporters should be restricted to this room to prevent them from interviewing miners' families or rescue teams, or from attempting to film family members or rescue workers, and from wandering about mine property.

Copies of all news releases should be given to the news media and reporters to prevent any confusion or misconstrued information from being released as facts. Additionally, a copy of each news release bearing the date and time of issuance, is to be kept on file for future reference and as company record.

8. Food and Sleeping Quarters- Often it is necessary to feed and house mine personnel during a mine emergency. Arrangements may have to be made for a caterer or nearby restaurant to bring in food. Sleeping quarters can be arranged at a nearby motel, or if none are available, sleeping quarters will be set up at the mine.

9. Laboratory- It will be necessary to test samples of the mine air during the rescue and recovery operation. A laboratory with suitable air analysis equipment should be set up at the mine to quickly obtain the results of the samples taken from the mine atmosphere. If it is not possible to set up a laboratory on-site, mine rescue vans with mobile laboratories can be called in to do quick air analyses. As a last resort, air samples can be sent off-site to a commercial laboratory.

10. Medical Facilities- Some medical services and facilities have to be available. If no one is trapped underground, a simple first aid station for rescue and recovery personnel who may get injured may be sufficient. However, in a disaster where several miners are trapped underground, or where injuries are substantial after an explosion, roof fall, or fire, it may be necessary to staff a temporary hospital. Stand-by ambulances, emergency medical technicians (EMTs) may be required also.

11. Temporary Morgue- In critical situations where bodies are being recovered from the mine, a temporary morgue will be necessary.

b. Suggested Personnel and Their Duties- Many people will be required to perform various rescue tasks, and some duties may seem more important than others since some assignments will range from ordering necessary supplies and seeing that they go where they are supposed to, while others will include actual rescue procedures. It is essential, however, that each rescue team staff member be able to perform his or her described duties correctly and quickly in order for the rescue and recovery operation to run efficiently.

Listed below are personnel who may be involved in the surface organization during a mine emergency, along with their duties. This is a suggested plan for dividing emergency tasks among personnel, but the actual assignments will vary from mine to mine, and depend on available personnel.

1. Mine Superintendent-The mine superintendent is in charge of the entire mine emergency operation. The mine superintendent is responsible for establishing the command center and overseeing all aspects of the rescue and recovery operation. The mine superintendent delegates the responsibility for various aspects of the operation as necessary according to a prearranged plan. If the mine superintendent for some reason is unavailable, someone designated by a prearranged plan should take charge of the operation.

It is suggested that the superintendent establish an advisory committee comprised of company and federal representatives and state and union representatives to serve and advise during each shift at the command center.

This committee, along with the mine superintendent, could act as a briefing and debriefing committee to inform teams entering the mine and gather information from teams exiting the mine.

The superintendent should designate an official to serve as the fresh air base coordinator for each shift, plus an advisory committee to serve and advise the coordinator during each shift at the command center. The superintendent should designate someone to direct the information center and issue news releases.

The superintendent should delegate personnel to:

Notify the families of any trapped miners. Notification should be done in person, if possible;

Notify the families of any miners or other personnel authorized to stay at the mine site as emergency operations personnel:

Monitor the underground phone circuit continuously whether or not it appears to be operational; and

Obtain gas samples from the main returns.

2. Mine Clerk- The mine clerk is usually designated to be responsible for all necessary communication coming into and out of the command center.

Duties of the mine clerk are:

Notify all persons listed on the notification plan and inform them of the emergency; Attend the telephone at the command center; and Assign people for errand duty.

3. Chief Electrician-The duties of the chief electrician are to:

Pull and immediately lock out all electric switches controlling the electricity to the mine, when authorized by the person in charge; Provide the materials for extra telephone communications as needed; and Arrange for any needed assistants.

4. Chief Mechanic or Mechanical Foreman-The duties of the chief mechanic are to:

Check explosion doors (for exhausting fan) or weak wall (for blowing fan) for damage. Make sure explosion doors are closed or the weak wall is repaired;

Check fan. Instruct an electrician or machinist to make tan repairs if necessary;

Monitor the operation of the fan and the atmosphere in and around the fan house if the fan is exhausting. With an exhausting fan, proper precautions should be taken to avoid asphyxiation or an explosion in the fan house; and

Alter ventilation only when ordered to do so by the person in charge

5. Outside Foreman- The duties of the outside foreman are to:

a. Arrange for guards and state or local police to:

Rope off and guard all mine openings; Guard all roads and paths leading to the mine;

b. Designate a person as a checkman to monitor people entering and leaving the mine. The checkman should:

Attend the assigned station within the roped off area;

Allow no one to go underground except persons authorized by officials in charge; Examine each person (entering the mine) for matches and smoking materials, making no exceptions; Check off each person by name and number, and record the time that they enter and leave the mine;

c. Set up an eating area and make sure that ample food and beverages are available for the rescue teams and other personnel; and

d. Set up medical facilities (first aid room, triage center, emergency hospital), restrooms, arrange for sleeping quarters, and a temporary morgue, if necessary.

6. Safety Director- The safety director is usually responsible for the mine rescue teams. The safety director's duties are to:

Assemble mine rescue teams and first aid crews; Provide facilities and equipment for testing, cleaning, and recharging the breathing apparatus;

Assign personnel to issue, record, and return mine rescue equipment;

Consult with the superintendent regarding plans for the rescue and recovery operation; and Establish a rotation schedule for the rescue teams.

The rotation schedule should be designed to show the clear order of team usage with backup teams always available. Adequate time must be allotted to permit teams to rest, clean, test, and repair the apparatus. It is recommended that there be three rescue teams ready and available at the mine before any rescue operation begins.

0x01 graphic

7. Chief Engineer- The duties of the chief engineer are to:

a Supply the command center with copies of maps showing the regular flow of air and the location of the ventilation controls, doors, pumps, substations, machinery, and the electrical system with the control switch locations;

Alert adjoining mines if they are connected underground with the affected mine;

Obtain maps of adjoining mines, if needed; and Make arrangements to furnish drilling rig equipment if needed.

8. Supply Clerk- The supply clerk is responsible for obtaining and distributing all of the equipment and supplies used for the emergency operation. The duties

of the supply clerk are to:

Prepare an inventory of the existing equipment and supplies;

Contact other mines and suppliers to obtain other needed supplies and equipment; Provide the following items for immediate use: nails, brattice cloth, hatchets, axes, saws, picks, boards, telephones, wires, any needed gas-testing equipment, sledge hammers, slate bars, shovels, suitable roof supports, lifting jacks, stretchers, batteries, and first aid cabinets; Provide the following items for authorized personnel: coveralls, safety shoes, gloves, caps, flashlights, safety glasses, and lamp belts; and Keep a record of all equipment issued and returned.

9. Lampman- The lampman is responsible for issuing all cap lamps, self-rescuers, check numbers or tags. The duties of the lampman are to:

Check that each person receiving a lamp is approved by the superintendent;

Record the equipment issued and returned; Give a check number to each person going underground; Record the name and number of each person going underground in a book.

10. Mine Foreman- The duties of the mine foreman are to:

Organize underground operations for each shift in cooperation with the person in charge, federal inspectors, and state inspectors (if involved), and union representatives, and Provide suitable transportation for people and supplies, as needed

11. Other Company Personnel- The duties of the other company personnel are to:

Assemble organizations according to the prearranged plan, and stand by until ordered to assist or leave.

Section 4

Mine Exploration

Barefaced exploration

The fresh air base

Establishing
Coordinator
Advancing

Apparatus teams

Team's role
Equipment

Team members equipment
What the law requires
Other

Briefing

Going underground

captain's responsibilities
getting under oxygen
team check
communications
team signals
communications with fresh air base

I. Introduction - "Exploration" is the term we use to describe the process of assessing conditions underground and locating miners (or clues to their whereabouts) during a rescue or recovery operation.

Exploration is a broad topic. We'll be talking about preparations for explorations, team briefings and debriefings, standard procedures for advancing inside the mine, and the equipment you'll be using during exploration.

II. Examination of mine openings- Before anyone goes underground, it's important to examine the mine openings to determine the safest route for entering the mine. Tests should be made for the presence of gases, and someone should make ventilation checks.

Whenever possible, it's best to enter the mine by way of the safest intake airway.

In a shaft mine, check the cage to make sure it's operating properly. To test an automatic elevator, run it up and down the shaft manually several times.

Tests should also be made for the presence of gases, smoke, or water in the shaft.

If a mine has had an explosion, the cage, signaling devices, and head-frame may be damaged. You may have to use a mucking bucket or other improvised means to make your descent provided all 5 team members will fit. However, a cage should be made available as soon as possible.

III. Barefaced exploration- In some disaster situations, conditions may make it possible to conduct an initial exploration without self-contained breathing apparatus. This is known as "barefaced" exploration.

Often, barefaced exploration is conducted with apparatus on team members, "ready" to function. This allows the team to quickly put on their facepieces and get under oxygen if conditions make it necessary.

Barefaced exploration should be conducted only when the ventilation system is operating properly and frequent gas tests indicate that there is sufficient oxygen and no buildup of carbon monoxide or other dangerous gases.

A backup crew with apparatus should be stationed outside the area, ready to go in immediately to rescue the others if necessary.

The purpose of such exploration is to quickly establish the extent of damage and to progress to the point where apparatus teams can continue the exploration.

Locomotives can be used during barefaced exploration as long as there is no smoke and no evidence of explosive gases. Usually, two locomotives are used in case one breaks down.

During barefaced exploration, the crew uses the mine's communication system to report their progress and findings to the surface. This lets the backup team know where the barefaced team is located and whether it's necessary to go in after them.

Barefaced exploration should stop at any point where disruptions in ventilation are found, or when gas tests indicate the presence of any carbon monoxide or other noxious gases, elevated readings of explosive gases, or an oxygen deficiency. A barefaced crew should also stop exploration when they encounter smoke or damage.

A fresh air base is usually established at the point where conditions no longer permit barefaced exploration. Because . the area has already been explored, rescue team members and backup personnel are then free to travel to and from the fresh air base without apparatus. Teams equipped with apparatus and under oxygen continue exploration from the fresh air base.

IV. The fresh air base- The fresh air base is the base of operations from which rescue and recovery work advances into irrespirable atmospheres. This is where apparatus crews begin their exploration of the affected area.

The fresh air base also functions as a base of communications for the operation linking the team, the command center, and all support personnel.

a. Establishing a Fresh Air Base- Often, the operation's initial fresh air base will be established somewhere underground. But in some mines, especially shaft mines, it may be necessary to establish the initial fresh air base on the surface. And sometimes the fresh air base will remain on the surface throughout the entire operation.

Whether you put it underground or on the surface, the fresh air base should be located as close as possible to the affected area of the mine, but situated where it's assured a supply of good air.

Underground, existing refuge chambers are sometimes used as fresh air bases. Or, a fresh air base can be set up in a drift, entry (for single-level, room-and-pillar mines), or crosscut close to the affected area. In these cases, an air lock must be built to isolate the fresh air base from the unexplored area beyond it. The air lock allows teams to enter and exit the unexplored area without contaminating the air in the fresh air base.

Here are some specific factors to take into consideration when you select a site for a fresh air base:

1. Be sure the fresh air base is located where it's assured positive ventilation and fresh air.

2. If the fresh air base is underground, it should be located where it's assured a fresh air travelway to the surface. This travelway will be used to safely move people and supplies to and from the fresh air base. If possible, there should also be transportation available.

3. The site should be situated where it can be linked to the command center by means of a communication system.

4. There should also be a communication system to link the team and the fresh air base.

These four are probably the most important factors that help determine where to establish a fresh air base, but there are also some other elements to take into consideration. For example, the area should be free of oil and grease.

Also, the fresh air base should be large enough to accommodate all the people who will be using it and allow enough space for them to work efficiently.

It is often recommended that all possible electrical conductors (track, pipe, wires, etc.) be severed so that the affected area beyond the fresh air base is isolated from any possible stray or direct current.

The fresh air base is normally outfitted with supplies and other equipment to be used during the operation. For example, a typical fresh air base will probably be equipped with gas testing devices, equipment for detecting oxygen deficiency, and perhaps firefighting equipment.

There may also be first aid supplies and oxygen therapy equipment at the fresh air base, as well as tools and replacement parts for self-contained breathing apparatus. And, there should be a map of the affected area at the fresh air base.

If possible, the fresh air base should be supplied with benches, canvas, or brattice cloth for the backup team to set their apparatus on.

b. The Fresh Air Base Coordinator- Stationed at the fresh air base, there will be a person who is responsible for establishing and maintaining orderly operations. This is the "fresh air base coordinator."

There will also probably be an advisory committee at the fresh air base to help the coordinator. This committee is usually composed of Federal and state officials, and union representatives, if involved.

And, sometimes "runners" are stationed at the fresh air base to carry messages from the fresh air base to the command center in the event of a communication breakdown. The runners may also be responsible for other chores, such as taking gas samples to the surface or monitoring the communication system cable.

The main responsibilities of the fresh air base coordinator are:

1. Maintaining communications with the working rescue team and the command center;

2. Following the team's progress on the mine map and marking findings on the map as the team reports them; and

3. Coordinating and overseeing the activities of all personnel who are at the fresh air base, including the advisory committee.

Fulfilling these three basic responsibilities involves performing a number of duties. The coordinator carries out many of these duties. Some of the tasks may be delegated to other individuals, but it's the coordinator's responsibility to see that they're carried out.

Let's take a look at the fresh air base coordinator's responsibilities during a typical operation.

An incoming coordinator who is replacing another coordinator should get all necessary information from the outgoing coordinator to ensure that the changeover goes smoothly.

It's also the incoming coordinator's duty to check communications between the fresh air base and the command center to make sure the system is operating properly. The coordinator also usually reports his or her arrival at the fresh air base, and logs the arrival time.

In addition to this, the coordinator's duties typically include checking the name or number of the team going into the affected area to work, checking the condition of the backup team, and checking and logging equipment and materials. The coordinator should also make sure there is a map of the affected area at the fresh air base.

A fresh air base coordinator is normally responsible for logging the times that all personnel enter and leave the fresh air base, and for logging the time and nature of all telephone calls.

As work progresses, the fresh air base coordinator monitors communications from the working team, relays instructions from the command center to the team, and provides information to the backup team based on reports received.

It's also usually the coordinator's responsibility to make sure someone is stationed at the fresh air base to monitor the team's communication cable if this type of communication system is being used. This person should help to unroll the cable as the team advances and roll it back up as the team retreats.

The coordinator should also make sure the requirements for a fresh air base are constantly maintained. It is typically the coordinator's responsibility to make sure that no unauthorized personnel are permitted to go forward of the fresh air base.

As you can see, the fresh air base coordinator plays a key role in ensuring that the entire operation runs smoothly and efficiently. The coordinator maintains crucial communication links with the command center and the working rescue team. In addition, the coordinator is responsible for just about everything that goes on at the fresh air base.

Because the coordinator's job is such an important one, it is absolutely essential that everyone at the fresh air base respect the coordinator's authority and do whatever they can do to help out. In order to make the fresh air base coordinator's job a little easier, it's also essential that only those people necessary to the operation be permitted at the fresh air base.

c. Advancing the Fresh Air Base- In single level mines using the room-and-pillar system, the fresh air base is usually advanced closer to the affected area of the mine as soon as areas forward of the base are explored and reventilated. This assures that the apparatus crews will begin their explorations as close as possible to the affected area of the mine.

To advance the fresh air base, the team will have to build a new air-lock at the site of the new fresh air base, and put up any additional temporary bulkheads in parallel entries that are needed to seal off the area at that point so that fresh air can be advanced.

Also, the team will have to repair any damaged ventilation controls in the area between the old fresh air base and the new one. However, be sure to make the necessary adjustments for directing air to an exhaust airway. This ensures that the area can be properly flushed out and ventilated.

Next, return to the old fresh air base and remove or open that air lock and any bulkheads in parallel entries. This permits air to enter and flush out the area up to the new fresh air base.

Before everyone is moved up to the new fresh air base, the area between the old and the new base should be explored by a team. Using appropriate gas testing devices, the team should check all dead ends, intersections, and high places in the area to make sure it's adequately ventilated.

Once the entire area is explored, all appropriate checks have been made, and the area is declared safe, the team and other fresh air base personnel can move up to the new fresh air base.

V. Apparatus teams- Once the fresh air base is established, apparatus teams will begin to explore the affected area.

This exploration may require only one or two trips, or it may continue through many team rotations. How many oh trips will be needed to complete the exploration (and how long it will take) will depend on the extent of the area involved and the conditions within the affected area.

a. Team's Role in Exploration- During exploration, the rescue team travels in potentially hazardous atmospheres.

As the team progresses through the mine, team members make gas tests and assess conditions. The team also searches for clues as to where survivors may be located, and locates fires. All these findings are mapped and reported to the fresh air base as the team proceeds.

As you explore, keep in mind that your first priority is team safety. The rescue of survivors comes second. Your third priority is the recovery of the mine.

During exploration, teams will work according to a rotation schedule.

One team, for example, will be scheduled to work. A second team will be stationed at the fresh air base as the "backup team," and a third team, known as the "standby," will be ready and waiting on the surface. Other teams may be scheduled to rest.

Because rescue work is strenuous and demanding, it's important for team members to be well rested. It's also recommended that you don't eat within one hour of the time you'll be wearing your apparatus, and you shouldn't drink alcoholic beverages for at least 12 to 18 hours before you get under oxygen.

Lack of sleep, a recent meal, or alcoholic beverages can cause you to be sluggish and impair your judgment and reflexes. It's also a good idea to limit intake of stimulants, such as coffee, colas, etc., because these substances increase heart and respiration rates.

b. Equipment-Equipment for exploration work falls into two categories: the equipment each team member has, and the equipment the team uses.

1. Team Members Equipment- Rescue team members use some of the same basic equipment that any underground miner uses. For example, each member will be outfitted with a hard hat, a cap lamp, steel-toed shoes or boots, and a metal I.D. tag.

For rescue work, you will also wear a metal ring on your mine belt so you can hook onto a link-line, and it is common practice for everyone to wear a watch. Of course each team member will also wear a self-contained breathing apparatus.

2. Team Equipment-What the Law Requires- Some of the equipment your team will use for exploration is required by law. For example, remember that the law requires your rescue station to be equipped with two gas detectors for each type of gas you may encounter and two oxygen indicators.

According to law, the team must also have a portable or sound-powered communication system. The system's wire or cable must be at least 1,000 feet long, and it must be strong enough to be used as a manual communications system.

3. Other Equipment- Beyond what is required by law, the other equipment your team will use depends on the situation.

For example, if you are rescuing survivors, the team will, probably carry a stretcher or stokes basket, and an extra-approved breathing apparatus for the rescued person. But if your task is to build ventilation controls, the team will probably carry tools and other construction equipment.

Some of the material you need to build ventilation controls may already be underground, so you will simply pick up what the team needs as you progress through the mine. This also applies to other team tasks that require the use of materials already inside the mine. The team simply picks up what it needs as it advances.

As you can see, the equipment your team uses beyond what the law requires is determined by what type of work you'll be doing. Here are some examples of equipment a typical mine rescue team might use:

1. gas detectors (or multi-gas detector)

2. oxygen indicators

3. communication equipment

4. thermal imaging cameras or heat sensing devices

5. link-line- This is a line or rope, usually equipped with rings, that is used to hook team members together in smoke.

6. Map-board and marker- (The map-board may be fitted with a plexiglass cover to protect the map from water damage in wet mines.)

7. scaling bar

8. walking stick- The captain can use a walking stick to probe water depth or to avoid obstructions in heavy smoke.

9. stokes basket or stretcher

10. first aid kit

11. fire extinguisher

12. tools - This usually includes: hammer, nails, axe, shovel, brattice cloth, and possibly a saw, and a wrench to open water line valves.

13. blankets (if missing miners are involved)

14. an extra approved breathing apparatus (if missing miners are involved)

15. carpenter's apron The captain may use an apron to carry a notebook, pen, and chalk. Other team members may use one for carrying nails, hand tools, and so forth.

VI. Briefing- Before your team goes underground, you will attend a briefing session. This usually takes place at the command center and is conducted by a briefing officer and a briefing committee.

The briefing committee is generally composed of company and Federal officials and, where applicable, state and union representatives.

At the briefing, you should be told as much as possible about what has happened in the mine and what conditions currently exist.

In addition, the briefing officer will give the captain the team's assignment. This assignment specifies what areas your team will explore and what you will be looking for.

The briefing officer will also issue your team an up-to-date mine map and give you a time limit within which You should be able to complete your work and return to the fresh air base.

During the briefing, the briefing officer will try to give you whatever information is available. However, it is your responsibility as team members to be sure you have all the information you need to do your work. Before you begin exploration, you should have the answers to the following questions:

1. Is the evacuation complete? Are any miners missing? If so, how many and what are their possible locations?

2. What is known about the cause of the disaster?

3. Is your team the first one to explore? (In multi4evel mines, the team would also want to know if there are any other teams working on other levels.)

4. Have the shaft and hoist been checked and, if so, what condition are they in?

5. Have state and Federal officials been notified?

6. Are guards stationed at all mine entrances?

7. Is the ventilation system operating? Is it an intake or exhaust system? Are attendants posted at the surface ventilation controls? Have air samples been taken? If so, what are the results?

8. Will there be a backup team standing by at the fresh air base, and reserve teams on the surface?

9. What are the team's objectives and what is their time limit?

10. What conditions are known to exist underground? (Ground conditions, water, gas, etc.)

11. Is the mine's communication system operating? Is it being monitored?

12. Is power to the affected area on or off

13. Is there diesel or battery-powered equipment or a charging station in the affected area?

14. What type of equipment is in the area? Where is it located?

15. Where are compressed air and/or water lines located? Are they in operation? Are valves known to be open or closed?

16. What type of firefighting equipment is located underground? Where is it?

17. What tools and supplies are available underground? Where are they?

18. Are there storage areas for oil or oxygen, acetylene tanks, or explosives in the area to be explored?

VII. Going underground

a. Captain's Responsibilities- Before your team proceeds to the fresh air base, it is the captain's responsibility to make sure the team, its equipment, and its apparatus are ready to go. In this capacity, the captain should:

1. Check each team member to make sure he or she is physically fit to wear the apparatus and to perform rescue work.

2. Make sure that each team member's apparatus has been properly prepared and tested.

3. Make sure the team has all necessary tools and equipment (including the captain's own supplies: notebook, pencil, chalk, and so on).

Once your team arrives at the fresh air base, it's the captain's responsibility to make the final preparations and arrangements before the team proceeds beyond the fresh air base. The captain should:

1. Make sure the team members understand the briefing instructions and what their individual jobs will be.

2. Make sure the gas-testing equipment, the communication equipment, signaling equipment, and stokes basket or stretcher have been checked by the designated people.

3. Establish with the fresh air base coordinator what communications will be used.

4. Synchronize watches with the fresh air base coordinator.

5. (If not the first team to explore) Get up-to-date information from the last team (or from the coordinator) about how far the last team advanced and what they found.

6. Make sure your team's mapman gets an updated map from the last team's mapman or from the fresh air base coordinator.

b. Getting Under Oxygen- Once all of these preparations and last-minute checks have been made, you're ready to put on your apparatus and get under oxygen.

Once the team is under oxygen, the captain checks each team member and breathing apparatus. The co-captain performs the same checks on the team captain.

When the checks are completed, the captain notifies the fresh air base coordinator that the team is ready to proceed, and asks permission to set out.

Before the team leaves the fresh air base to begin the exploration, the captain should be sure to take note of the time of departure. Some teams jot down the time on their map for later reference.

Every exploration is different. Each one is an unknown situation, so each presents its own problems.

Although it's difficult to tell exactly what you'll be doing during any exploration, there are some accepted procedures for carrying out basic exploration work. These procedures have developed over the years as mine rescue teams gained experience. They should be thought of as "guidelines" rather than "rules" because they are fairly flexible.

Let's take a look now at some of the standard techniques and procedures you'll use during exploration.

c. Team Check- One standard procedure you'll use during an exploration is the "team check." There are three reasons for the team check:

1. To make sure each team member is fit and ready to continue,

2. To make sure each team member's apparatus is functioning property, and

3. To give the team a chance to rest.

Usually, the captain conducts the team checks by simply halting the team briefly, asking each team member how he or she feels, and checking each apparatus.

It's recommended that these team checks be conducted every 15 to 20 minutes.

It is also recommended that you make your first stop for a team check as soon as possible after leaving the fresh air base. There is a good reason for stopping close to the fresh air base: If a team member is feeling unfit to travel or an apparatus is malfunctioning, the journey back to the fresh air base is relatively quick and easy at this point.

For teams using a compressed oxygen breathing apparatus, the captain usually notes each team member's gauge reading at each rest stop, and reports the lowest reading to the fresh air base. The lowest reading may then be used as a reference point to determine when the team should return to the fresh air base.

Keep in mind that in addition to checking each team member and apparatus, these stops allow the team a chance to rest. If your team is searching for survivors, you'll probably want to advance quickly, but rest stops are still important. Be sure to allow time for them.

How long you stop for each check will be determined by the conditions you encounter and the work you are doing.

Rest stops are also, important(perhaps more so) on the return trip. The team will usually be more tired once they've completed their work. Don't forget to allow time for team checks as you travel back to the fresh air base.

d. Communications- As you travel beyond the fresh air base, communication plays an increasingly important role in your exploratory work. It is extremely important that teams develop an effective method of communicating among themselves and with the fresh air base.

e. Team Signals- In case of communication failure, the team should use the standard life line signals. It is advisable that if communications fail, the team should immediately return to the fresh air base to determine the problem. The signals most commonly used are:

One pulls: Stop

Two pulls: Advance inby

Three pulls: Retreat outby

Four pulls: Distress or emergency

f. Communication with the Fresh Air Base- As the team advances, it's important to stay in close contact with the fresh air base to report your team's progress and to receive further instructions.

To communicate with the fresh air base, you will generally use either sound or battery-powered communication equipment. Usually one team member wears the equipment, and is responsible for sending information to the fresh air base and relaying instructions from the fresh air base to the team.

Existing underground phones, if operational, may also be used to communicate with the fresh air base.

Section 5

Mine Ventilation

Table of Contents

Introduction
Mine ventilation

airflow
mine fans

Ventilation maps

purpose
map symbols

Types of ventilation controls

stoppings

permanent stoppings
temporary stoppings

check curtains or runs
line braftice
auxiliary fans & tubing
overcasts & undercasts
mine doors
regulators
box checks and regulators

Assessing ventilation

reporting conditions
measuring flow

anemometer
smoke tubes

building ventilation controls

temporary stoppings
permanent stoppings
air locks

I. Introduction

Mine rescue teams have to know the basics of mine ventilation, and secondly, teams have to know how to build mine ventilation controls. Why? During a mine emergency, after an explosion, fire, flood, or whatever the emergency situation is, rescue teams are needed to enter the mine and assess the damage to the ventilation system and reestablish mine ventilation if necessary.

The initial responsibility the rescue team is to report the status of the ventilation system to the command center as the team advances. It is quite possible that the mine ventilation system was damaged or controls were altered during the emergency. Accurate information on the condition of the ventilation has to be given to the command center.

Note: Never alter the mine ventilation without specific, direct orders from the command center.

Mine Ventilation

The command center must rely on information supplied by the rescue team. If ventilation controls have been changed or damaged, the command center can then direct the rescue team on how to reestablish ventilation in the mine.

Team members should know the following:

What is the purpose of mine ventilation?

What are the various ventilation controls?

What purpose do ventilation controls serve?

How do ventilation controls affect mine exploration and rescue?

What are the various symbols used to record ventilation controls and airflow on a ventilation map?

a. Airflow- Every underground coal mine contains harmful gases, dust, fumes, and smoke. Adequate oxygen must be provided throughout the mine for miners to be able to breathe underground. The basic principle of ventilation is controlling or moving (coursing) air currents.

When a mine is ventilated, air from the surface enters the mine at the main intake shaft(s) and is directed or coursed through the mine by a system of ventilation controls. These controls force the air to move in certain directions and at certain velocities to safely ventilate all mine sections.

All return air from the working sections is then rechanneled to the main return and eventually leaves the mine. In order to get airflow, there has to be a difference in air pressure between the intake and the return airways. Air moves from a high-pressure area to a low-pressure area. In order to accomplish that kind of air movement, mine fans are used.

b. Mine Fans- Mine fans create a difference in air pressure (pressure differential) by changing the air pressure at specified points in the mine. The greater the pressure difference the fan creates, the faster is the flow of air. Using a fan to create the pressure differential is known as mechanical ventilation.

Mine fans create the atmospheric pressure differential within the mine by either blowing air into the mine or exhausting the air from the mine. The exhaust fan pulls stale air out of the return, and by pulling out that air, causes a pressure differential, which then pulls fresh air into the mine.

Blower fans are typically used in mines having little overburden. Many of these mines have surface fractures. By using a blower fan, it allows air to leak through those fractures and away from the mine rather than returning air to the mine. Small mines can use one fan for ventilation, but large mines with vast underground workings use several main fans, with each fan used to ventilate specific sections.

When rescue teams are working in a mine with several main fans, teams must be familiar with each ventilation plan for the separately ventilated areas of the mine.

Note: In an emergency situation, to ensure the rescue team's safety while underground after the fresh air base is established and exploration Is underway, the main fan (or fans) must be monitored or guarded by an authorized individual to make sure the fan operates continuously or to notify the command center if the ventilation system breaks down.

If the mine fan quits while the team is underground, hazardous conditions can ensue without all rescue team members knowing it, and can further endanger trapped miners. If hazardous conditions ensue from the fan being down, rescue teams will be recalled from the mine.

Additionally, having the fan monitored or guarded ensures that no one alters the operation of the mine fan and changes the ventilation controls without direct orders from the command center.

Ill. Ventilation Maps

a. Purpose- All mine rescue team members, particularly the team's mapman, should know how to read a mine map showing mine ventilation. The mapman is responsible for marking down information on the map to assess ventilation during exploration. The team mapper should attach a legend of the map symbols used by a particular mine at the bottom of the map or mapboard, as well as the scale to which the map is drawn since these maps can differ from mine to mine.

Rescue teams will be given up-to-date mine ventilation maps after the team's briefing, and before going underground. Teams should study the map to familiarize themselves with the layout of the area to be explored, and to know what to expect. If previous teams have already explored some areas, the map will indicate what was found and done on prior explorations. Teams will need to know the map symbols as well.

B. Map Symbols- Mine rescue teams need to know map symbols in order to understand the ventilation controls and how they affect the movement of air in the mine. Some of the symbols commonly used on mine maps are:

Devices for Controlling Ventilation

Permanent Stopping	Temporary stopping	Permanent Stopping w/door
Overcast or Undercast	Airlock	Line Curtain/Brattice Cloth
Line Curtain/Brattice Cloth	Regulator	Direction of Intake Air
Direction of Return Air

IV. Types of Ventilation Controls

Ventilation controls are needed and used underground to properly distribute the air to all mine sections. The ventilation controls can do so by controlling the direction of the airflow as well as the amount of air that travels through the mine.

Each working section must be ventilated with a separate supply of fresh air. Ventilation controls are used to split off fresh air from the main intake and direct it to each section since each working section must be ventilated with its own separate supply of fresh, uncontaminated air.

The various ventilation controls work collectively to direct or "course" the movement of the air through the main intakes to the working section and move out through the returns without Short-circuiting. Short-circuiting occurs when air from the intake goes directly into the return without moving up and ventilating the working face areas inside the mine.

Listed below are the ventilation controls commonly encountered by rescue teams with a brief description of the effects each of these devices has on exploration and rescue.

a. Stoppings- Stoppings are used to close off the crosscuts in order to prevent the air in one entry from moving into the return air of the adjacent entry. Stoppings are either permanent or temporary.

1. Permanent Stoppings are built of concrete blocks or other noncombustible material. They are used in areas of the mine where ventilation is well established. Permanent stoppings are tightly sealed against the mine roof, floor, or ribs to prevent any air leakage.

Sometimes permanent stoppings are designed with a man-door or drop-door in them to allow miners to pass through one crosscut entry to another. These man-doors are not designed for ventilation controls, but if a man-door is propped open, it can affect the airflow and may cause intake air to short-circuit into the return.

2. Temporary Stoppings are used in actively working sections of the mine where ventilation is changed as needed, to direct the airflow until a permanent stopping, which is stronger and more airtight, can be erected.

Temporary stoppings are usually built of canvas, brattice cloth, or plastic. Occasionally they are constructed of wood or metal.

The mine rescue team may have to construct temporary stoppings to advance ventilation during exploration or recovery work. There are specially designed temporary stoppings for use in mine rescue work which are installed quickly and easily, and are very effective.

One of the special temporary stoppings in mine rescue work is an inflatable, rubberized stopping. Another type is a self-sealing stopping commonly referred to as a "parachute stopping." Additionally, urethane foam, which is available in pressurized containers, can be used to seal the edges of temporary stoppings to make them more airtight.

b. Check Curtains or Run-Through Checks- Check curtains (run-through checks) are curtains made of brattice cloth, canvas, or plastic which are hung across a passageway but open to let miners or their machinery go through. Check curtains deflect intake air into the working area. They fasten only at the top and are designed in three styles:

1) a one-piece curtain attached at the top and loose at the sides and bottom;

2) a curtain with a long vertical slit down the center which is attached at the top and sides; and

3) a curtain which has three overlapping flaps of material.

Check curtains are designed to close automatically after someone passes through them, and then they close to direct the air to the working area.

If check curtains get pulled down or do not fully close, air will short circuit and will not reach the working face.

Note: If rescue teams find check curtains that are pulled down or do not close fully, teams are to leave the curtains as they are and report the situation to the command center. Changes in ventilation can only be made by the command center. The command center will then decide on what to do concerning ventilation.

c. Line Brattice- Line brattice is brattice cloth or plastic used to course air from the last open crosscut to the working face. Line brattice is extended as the mining progresses to keep the air flowing to the face.

Brattice is hung from the roof to the floor extending from the end of the check curtain to within 10feet of the working face. It can be hung from a rough lumber frame, from timber posts, or from special fasteners. It can also be secured to the roof with spads.

Note: Line brattice is particularly useful for rescue teams to use to sweep out or ventilate a room area of the mine or when it is necessary to split an air current as teams advance ventilation.

d. Auxiliary Fans and Tubing- In large mines using continuous mining machines to cut great quantities of coal, large amounts of dust result. Auxiliary ventilation systems are often used to control and direct airflow to or from the face in those mines or where a line brattice does not provide adequate ventilation. These auxiliary systems consist of an auxiliary fan and tubing.

Auxiliary fans blow or exhaust air. The tubing, often suspended from timbers or roof bolts (if approved), carries the air to or away from the working face. Tubing is rigid for exhaust systems, or collapsible for blowing systems.

The auxiliary ventilation system allows the continuous miner to operate without being obstructed by line brattice usually required to ventilate the working face. The tubing can be moved easily to t he working face, making it convenient to extend ventilation to the face as mining advances.

e. Overcasts and Undercasts- Intake and return air often cross paths at intersections within the mine. Because of this, overcasts and undercasts are built to allow the two air currents to cross one another separately, without the intake air short circuiting into the return.

Overcasts are like enclosed bridges built above the normal mine roof level. Undercasts are like tunnels built below the normal mine floor. However, undercasts are seldomly used unless unstable roof is present since they fill with water or debris which would slow down the air current.

Overcasts are frequently used and are built with concrete block walls sealed against the ribs and floor, with some kind of airtight roof made of prestressed concrete, railroad ties, or steel beams. Frequently this kind of overcast is used to allow air to cross over a conveyor belt without mixing the split of air which ventilates the belt.

Sometimes overcasts are made of pipes going from one stopping to another, across an intake airway, allowing the return air to pass over the intake air.

f. Mine Doors- Mine doors are used to control ventilation in heavy-traffic areas such as haulageways. Doors are hung in pairs usually, to form an airlock which prevents a change in ventilation if one of the doors is opened. The doors are designed to direct the air flow from the haulage entry into another entry. Mine doors can also be used to isolate separate splits of air.

They can be opened one at a time to allow equipment and personnel to pass through without disturbing ventilation. These doors should always be opened and closed one at a time to maintain the airlock.

Mine doors can be manual or automatic. If the mine doors are manual, they are hung in such a way that the ventilation air pressure will close them if they are left open accidentally. Miners or other personnel should always close the manual doors after passing through. Other doors can be closed automatically.

Note: Rescue teams should be aware that if the normal flow of air is reversed within the mine, the ventilating air pressure will no longer keep the mine doors closed.

g. Regulators- Regulators are used in the mine to control and adjust the volume or quantity of airflow within the mine, in order to ensure proper distribution. Regulators are ventilation devices used to regulate airflow to meet the individual needs of each air split.

The types of mine regulators are listed below:

1) Section regulators are used in returns and are often sliding doors or windows built into the permanent stoppings near the mouth of a section. Opening or closing this door or window adjusts the air flow to a section. If one of these regulator doors has to be opened to allow miners to pass through, it must always be closed in the same position it was found.

2) Regulators can be made from knocking out a few blocks from a permanent stopping. The airflow can be adjusted by removing or replacing the blocks.

3) A check curtain can be used as a regulator when one corner is taken down. The corner opening lowers the air's resistance and lets more air flow.

Airflow can be adjusted by lowering the corner and making a larger opening, or by tacking it back up to make a smaller opening.

4) A check curtain can make another kind of regulator when it is hung so it does not reach the mine floor. Doing this lowers the air's resistance and allows more airflow. This kind of regulator is adjustable also.

5) A pipe overcast can serve as a regulator.

h. Box Checks and Regulators- Conveyor belts are usually in or near intake air passages. Because they are, if a belt were to catch on fire, smoke and carbon monoxide would mix with the intake air. It is for that reason that federal law requires that all underground belts be isolated from the main intake and return air. (Title 30, Code of Federal Regulations, Section: 75.326.) Also, conveyor belts must have their own split of air. That is accomplished by using box checks and belt regulators.

Box checks are temporary or permanent stoppings built at each end of the belt to limit the intake air flowing over the belt. The box checks are built with openings in them to permit the belt to pass through. They are designed to let a little air flow through them into the isolated belt entry which ventilates the belt with its own split of air.

After the belt is ventilated, the air is drawn through a belt regulator into the return airway. The belt regulator regulates the quantity of air flowing along the belt.

V. Assessing Ventilation

a. Reporting Ventilation Conditions- As the team advances through the mine during exploration, all ventilation controls should be checked, particularly those in the affected part of the mine. The position of the regulator doors should be noted on the map by the mapman, and then reported to the command center.

Command center officials must have accurate information from the mine rescue team concerning ventilation controls. Team members have to report up-to-date information to the command center in order for the officials to assess the situation correctly.

Team members should note the type of damage and the extent of damage. If a stopping or other type of structure is blown out from explosives, note the direction in which it appears to have blown. If the stoppings were not destroyed, indicate how the blocks moved.

The most positive indicator of the origin of an explosion is the direction in which the blocks moved in or from the stoppings across entries near intersections.

The movement of blocks from stoppings in crosscuts seldom indicates the origin of an explosion.

Note: Teams should never alter ventilation without direct orders from the command center. The command center considers several factors before it makes any change in ventilation. The command center has to evaluate how alterations will affect ventilation into an unexplored area. If teams must alter ventilation, do not alter the ventilation into unexplored areas.

The wrong alteration in the ventilation could cause changes in the fresh air base, pushing toxic gases or smoke into areas where miners are trapped, and force explosive gases back over fires or hotspots, and cause an explosion, or redirect or feed a fire.

Team members must know how to:

1. Recognize damaged or destroyed ventilation controls;

2. Determine the direction and velocity of ventilation air by using an anemometer or smoke tube; and

3. Measure the cross-sectional area of a mine entry and calculate the volume of air by using the area and velocity.

b. Measuring Flow-

1. Anemometer- Rescue teams will be asked to determine the direction and velocity of airflow in certain mine sections. The quantity of airflow can be calculated from the velocity. Being able to determine the direction and velocity of air flow enables the team to check the ventilation system and whether it is fully functioning or working only in a specific area.

By comparing readings reported by the rescue team with readings recorded from normal operation conditions, the command center can then assess the overall condition of the ventilation system. These readings should be reported to the fresh air base as soon as they are taken.

Anemometers and smoke tubes are the most commonly used instruments for measuring air direction and velocity. The anemometer is used for measuring normal-to-high velocities, while the smoke tube is used to measure slowly moving air and its velocity.

The anemometer is a small device like a windmill or propeller attached to a digital counter that records the revolutions caused by the moving air currant. It is used to measure air velocities of 120 to 10,000 feet per minute. It is used to measure and record the number of revolutions for a set period of time: usually 1 minute.

There are two types of anemometers:

1) A medium-velocity or regular anemometer to measure velocities from 120 to 2,000 feet per minute, and

2) A high-velocity anemometer to measure velocities from 2,000 to 10,000 feet per minute.

How does an anemometer calculate this information? The anemometer measures linear feet of travel and requires a time factor, usually 1 minute, to determine velocity in feet per minute. The area of the airway (where the reading is taken) is computed in square feet. The area is then multiplied by the velocity to obtain the quantity of the air current in cubic feet per minute.

How can rescue teams take these measurements? A standard method to measure the velocity of an airway is to transverse the airway to get an average measurement of the average velocity in the airway. The usual procedure is described below:

1. Stand placing your back against one rib and hold the anemometer in a vertical position out at arm's length, positioning the anemometer for the air current to enter the back of it (that is the side without the dials). Keep the free arm against the body.

2. Turn on the anemometer and slowly walk to the opposite rib at a pace to get a 1-minute reading, keeping the anemometer out in front to decrease as much air resistance as possible. The anemometer should be raised and lowered slowly while walking to the opposite rib to get an average velocity of air measured.

3. At the end of 1 minute, shut off the anemometer and read the dials. Correct that reading by using the manufacturer's table of corrections for the various velocity readings. The teams should read the manufacturer's instructions for the correct information on how to operate and read the anemometer.

4. Determine the cross-sectional area of the entry by multiplying the width times the height.

5. Report the velocity and area measurements to the command center. The command center will calculate the quantity of the airflow in cubic feet per minute:

Quantity (cubic feet) = Area (square feet) x Velocity (feet per minute)

Velocity is always measured in feet per minute for mine applications.

Occasionally the high velocities encountered are those flowing in ducts or tubing where measurements by an anemometer are difficult to obtain. For these kinds of measurements, the most practical instrument to use is the pitot tube. The pitot tube can be inserted through a small hole in the duct or tubing. The pitot tube has a-U-tube water gauge or some other differential pressure gauge for determining the velocity pressure inside the tubing.

2. Smoke Tube- The smoke tube is another type of device to measure airflow and is used to show the direction and velocity of slowly moving air (slower than 120feet per minute). It is usually used when airflow is too slow for an anemometer to calculate.

The smoke tube is a device which emits a cloud of smoke which floats with the air current showing the direction and velocity of the air. It consists of an aspirator bulb and a glass tube containing a smoke generating reagent.

To operate the smoke tube, break off both ends of the glass tube and then squeeze the aspirator bulb to force air into the tube. A white cloud of smoke will come out of the tube and travel with the air current. This smoke cloud shows the direction the air is moving (when it cannot be determined otherwise).

Note: If teams are not wearing breathing protection while working with the smoke tube, they should avoid being in contact with the smoke since It is very irritating and can cause choking.

There are two methods to measure air velocity with a smoke tube:

1. Take the reading in the center of the airway. This reading is not an accurate measurement but an approximate and high reading because the center of the airway has the fastest moving air.

2. Determine the air velocity at quarter points. Quarter points are points at approximately the center of each quadrant if the airway were divided into `lour "equal" parts. This method is done to determine the average velocity in the airway since it varies at different parts of the airway. The procedure for taking readings at quarter points within the airway is described below:

a) Mark off a distance in a relatively straight and uniform way. Usually 25 feet is all right for this measurement if the smoke cloud holds together and is visible.

b) Station one person with the smoke tube at the upwind point of the measured distance, and station another person at the downwind point with a stopwatch.

c) Release a smoke cloud at each quarter point within the airway. The person with the stopwatch must time each cloud from the moment it is released until it reaches the downwind point. Each measurement is taken separately for each smoke cloud released: the first, second, and so forth.

Note: Smoke-tube readings have to be converted to feet per minute.

For example, 25 feet is the measured distance and it averages 23 seconds for the smoke cloud to reach the downwind point. Determine the decimal equivalent of 23 seconds to find out what fraction of a minute it is:

Quantity = Area (200 ft [for example]) x 65.7 Quantity of airflow = 13,140 ft3/Min

Each velocity measurement in a quadrant should be taken several times to get an accurate average. Discard abnormally high and low measurements, and keep the remainder. A correction will have to be made to the averaged figure because the air travel at the quarter points will average about 10 percent high.

(Note: To make this correction for the 10 percent high reading, either multiply the averaged figure by 0.10 and subtract that number from the averaged figure, or multiply the averaged figure by 0.@.)

If the smoke tube is going to be used repeatedly, keep it tightly stopped with a rubber cap or plug since the reagent is very corrosive and can clog the tube openings.

VI. Building Ventilation Controls

Mine rescue and recovery work often requires building or rebuilding ventilation controls to reestablish ventilation within the mine. The rescue teams have to know how to build ventilation controls properly, including:

Temporary and permanent stoppings; Air locks; and Line brattices.

Some team members are skilled at building ventilation controls while other members are inexperienced. Whatever the case, it will take time to get used to whatever control is being worked on. It is very difficult to work in smoke while trying to work quickly in order to reach survivors as fast as possible.

Note: Teams must never make any alterations or do any construction without the approval of the command center.

a. Temporary Stoppings- To install a temporary stopping in a crosscut, the stopping has to be erected approximately 4 to 6 feet into the crosscut to allow enough room for a permanent stopping to be built later.

The ideal site for a temporary stopping is one where there is sound roof and ribs, with the floor free of debris in order to give a good seal around

the stopping. Test the roof and bar down any loose material from the roof.

The stopping is constructed by setting posts at each rib and in between if necessary, depending on the width of the crosscut. Nail boards across the top and bottom of the posts for attaching the brattice or plastic. Loose coal can be shoveled onto the excess cloth at the bottom of the stopping to seal the bottom of the stopping.

These stoppings are used to replace stoppings in crosscuts which were blown out or damaged. Temporary stoppings can be constructed quickly to advance ventilation to trapped miners.

If an explosion occurred, teams may encounter a great deal of debris, damage to stoppings, and hazardous roof and rib conditions. Therefore, teams may find it necessary to improvise and control ventilation as much as possible.

Where stoppings in crosscuts are destroyed or damaged or filled with debris, or have large pieces of equipment or contain mine cars, they can be sealed to advance ventilation.

Where this occurs, teams can hang brattice or plastic from the roof and cut and fit the brattice to fit around the piece of equipment or obstruction, and shovel loose material onto the excess brattice at the bottom and-onto the equipment to effect as tight a seal as possible.

Note: Non-sparking tools, nails, or spads must be used in mine atmospheres above 1 percent methane to reduce the chance of a spark causing an ignition. Non-sparking shovels must be used in and around temporary stoppings in such atmospheres.

Pogo sticks (spring-loaded expandable metal rods similar to a pole lamp) can be used instead of posts to erect temporary stoppings quickly since pogo sticks don't need to be cut and fitted. They can be used along with posts in wide crosscuts to reduce the number of posts which would normally be needed.

Rescue teams, through teamwork and practice with the proper materials, can erect adequate temporary stoppings quickly and efficiently.

b. Permanent Stoppings- Permanent stoppings are usually not constructed until ventilation is restored to the mine, but they should be built as soon as possible to replace any temporary stoppings. Usually these permanent stoppings are constructed outby the fresh air base and can be built by barefaced work crews instead of by the mine rescue teams.

However, there are times when the mine rescue team will be required to build a permanent stopping while under oxygen, such as to seal a fire area. This topic will be discussed in detail in the manual entitled: "Fires, Firefighting, and Explosions."

c. Air Locks- An air lock consists of two stoppings with flaps or doors constructed close together to create a space where team members can pass from one mine atmosphere to another without mixing the atmospheres.

To maintain the air lock, one door of the air lock must be kept closed when the other door is open.

In mine rescue work, the air locks are normally put up to establish a fresh air base enabling teams to move inby into questionable air without contaminating the fresh air base.

Air locks are used too, when a team has to break open a stopping or door when conditions on the other side of that stopping are unknown.

Note: Air locks are required prior to opening any barricade or door in irrespirable atmospheres where survivors may be located. If survivors have barricaded themselves in fresh air, the team could contaminate the air when breaking through the barricade. The air lock will prevent any changes in ventilation.

When erecting an air lock, teams should build the two stoppings as close together as possible while allowing enough room for the team and their equipment to fit in between.

d. Line Brattice- Mine rescue teams may find it necessary to use line brattice to sweep noxious or explosive gases from a face area or to split an air current as they advance ventilation.

Line brattice is constructed by installing posts and nailing boards along the roof and floor for attaching the brattice. Brattice can also be attached to the roof with spads or held up with pogo sticks, if they are available. Spads will hold up the brattice better if they are driven through with soda-bottle caps which act as washers.

If the brattice only needs to hang for a short time, the team can holdup the brattice, extending it to the area to be ventilated. In this instance, the team members should hold up their individual section close to the roof.

Section 6

Fires, Firefighting & Explosions

Introduction
Fires

Fire triangle
Classification of fires

Firefighting equipment

Dry chemical extinguishers

1. General information

2. How to use hand held extinguishers

PASS
Types of fire extinguishers

Using hand held extinguishers on an obstacle fire
How to use wheeled extinguishers

Rock dust
Water

Disadvantages
Waterlines

Nozzles
Hoseline
Nozzle streams

Fire cars
Fire cars/low expansion foam
Applying water to fires

d. High expansion foam

Description

Types of foam

Foam generators

Description
How to use

Fire fighting

Before going underground
Locating fires/assessing conditions

1) Tricket's Ratio

Direct fire fighting

General procedures
Hazards

a) Electric

Gases
Heat, smoke, and steam

Indirect firefighting

Sealing underground

Planning
Temporary seals

Types

Considerations of temporary seals

Air sampling tubes
Ventilation
Exploration
Isolation

Permanent seals

Types
Construction

Air sampling tubes

Taking air samples
Sealing the surface

Entire mine
Remote sealing
Foaming the area

Foaming the area
Flooding the mine

Explosions

Causes and effects
Going underground
Exploration

I. Introduction

Firefighting is probably the most frequent duty rescue teams perform. Fires in underground mines are especially hazardous because they produce smoke, toxic gases and heat, pose explosion hazards, and create oxygen-deficient atmospheres. Fires, firefighting, and explosions, and how they affect mine rescue teams will be explained in this manual.

II. Fires

Most mine fires result from a chemical reaction between a fuel and the oxygen in the air. Materials such as wood, coal, methane, gas, oil, grease, and many plastics burn when ignited in the presence of air. In each instance, three key elements are required at the same time for a fire to occur: fuel, oxygen, and heat (which is usually provided by the ignition source).

a. Fire Triangle- The "fire triangle" must have the three elements necessary for fire. On each point of the triangle is one of the necessary elements for fire: fuel, oxygen, or heat. These three elements must be present at the same time in order for fire to occur. Any time one of these elements is removed, the fire goes out. Equally important, if one of the elements is missing from the fire triangle, the fire will not start. Therefore, in order to extinguish a fire, it is necessary to remove one element of the point of the triangle.

Removing one of these elements from the fire triangle is the basis of all firefighting.

There are various methods for fighting a fire:

Fighting a fire with water removes the heat;

Smothering a fire with a noncombustible material, like rock dust, removes the oxygen;

Loading out hot materials from the fire area removes the fuel.

Another way to extinguish a fire is by stopping the chemical reaction between the fuel and the oxygen, which is the principle by which dry chemical extinguishers operate. The function of dry chemical extinguishers is to chemically inhibit the oxidation of the fuel which stops the f ire.

Note: The method to be used to fight a fire is determined by the materials which are burning and the conditions in the fire area. Therefore, a large part of the job for the mine rescue team is to explore the mine and assess the condition of the fire in order for the command center to know how to fight the fire.

b. Classification of Fires- Mine rescue teams must know the types of fires they are fighting in order to know how to extinguish them. The National Fire Protection Association lists four classes of fires: A, B, C, and D.

Class A Class A fires involve ordinary combustible materials such as wood, coal, paper, plastics, and cloth. They are best extinguished by cooling them with water, or by blanketing them with certain dry chemicals.

Class A fires leave Ashes.

Class B Class B fires involve flammable or combustible liquids like gasoline, diesel fuels, kerosene, or grease, as examples. These fires can occur when flammable liquids leak out of mechanical equipment or are spilled. The best way to extinguish Class B fires is to exclude air or use special chemicals that affect burning reactions.

Class B fires involve contents which Boil.

Class C Class C fires are electrical fires which typically involve electric motors, trolley wires, battery equipment, battery charging stations, transformers, and circuit breakers. They are best extinguished by nonconducting agents such as carbon dioxide and certain dry chemicals.

If power has been cut off to the burning equipment, the fire can then be treated as either a Class A or Class B fire.

Class C fires involve Current.

Class D Class D fires involve combustible metals such as magnesium, titanium, zirconium, sodium, and potassium. Special techniques and extinguishers were developed to extinguish these fires. Normal extinguishers should not be used on Class D fires since they may make them worse. However, the possibility of Class D fires occurring in coal mines is extremely rare.

Ill. Firefighting Equipment

Rescue teams must be able to identify the various types of firefighting equipment available. Mines have several different types of equipment for firefighting which include:

· Dry chemical extinguishers.

· Rock dust.

· Water.

· Foam.

a. Dry Chemical Extinguishers

1. General Information- Dry chemical extinguishers put out fires by stopping the chemical reaction between the fuel and oxygen (which produces the flame). These dry chemical agents work to inactivate the intermediate products of the flame reaction which reduces the combustion rate (rate of heat evolution) and extinguishes the fire.

Basically there are two sizes of dry chemical extinguishers:

1) Hand-held extinguishers which weigh between 2 and 55 lbs, and

2) Larger wheeled extinguishers, which weigh from 75 to 350 lbs. These extinguishers consist of a large nitrogen cylinder, a dry chemical chamber, and a hose with an operating valve at the nozzle.

Mine rescue teams usually use the multi-purpose dry chemical extinguishers which contain monoammonium phosphate because they are effective on Class A, B, or C fires. Monoammonium extinguishers eliminate the team's having to use separate extinguishers for each class of underground fire encountered.

2. How to Use Hand-Held Extinguishers- Note: Rescue team members must check the label on the side of the extinguisher before attempting to extinguish any fire. Using the wrong type of extinguisher can spread the fire instead of putting it out.

a. When extinguishing a fire "PASS"

P Pull the pin

A Aim low

S Squeeze the handle

S Sweep from side to side

b. Types of fire extinguishers

Monammonium phosphate

Rated for ABC fires, interrupts the basic chemistry of fire.

Not recommended for D fires. (Red body & pressure gauge)

CO2

Rated for BC fires, will only extinguish surface area, heated core may reignite. (Red body & horn, no gauge)

Halon

Rated for BC fires, used mainly in electronics, dangerous because Halon displaces oxygen. (Red body and gauge)

Pressurized Water

Rated for A fires only, usually a baking soda charge. (Stainless steel body)

The label lists information regarding the distance from which the extinguisher is effective. Most dry chemical extinguishers are effective from 5 to 8 feet from the f ire while larger units have ranges from 5 to 20 feet from the fire.

To operate a hand-held extinguisher: grasp it firmly and approach the fire from the intake side. Hold the nozzle down at a 45-degree angle. Stay low to avoid any roll back from the flames but try to get within 6 to 8 feet of the fire before turning on the extinguisher.

To effectively and quickly extinguish the fire, direct the stream of dry chemical to about 6 inches ahead of the flame edge.

Begin far enough away to let the discharge stream fan out. Use a side-to-side sweeping motion to cover the fire with the dry chemical. Each sweep of the chemical should be slightly wider than the near edge of the fire.

While putting out the closest fire, advance slowly toward it, forcing it back. Always be alert for re-ignition of the fire even if it looks extinguished.

The discharge time of hand-held extinguishers varies from 8 to 60 seconds, depending on the size and type of the fire extinguisher. A 30-pound extinguisher usually lasts from 18 to 25 seconds. Always have control of the extinguisher or other team members could be exposed to the dry chemical stream.

3. Using Hand-Held Extinguishers on an Obstacle Fire- If an obstacle fire occurs with flaming equipment at the center, two people using hand-held extinguishers should try to put it out instead of only one person attempting to do so. It is often impossible for one person to put out this type of fire.

The two firefighters should approach the fire together from the intake airside, holding the extinguisher nozzle down at a 45-degree angle. Both streams of dry chemical should be directed to 6 inches ahead of the flame edge.

The two fire fighters should split up and slowly advance around each side of the obstacle while trying to keep up with each other as much as possible. Each person should cover two-thirds of the f ire area, and use a side-to-side sweeping motion with the extinguisher's stream.

When the fire appears to be extinguished, both fire fighters should remain on alert for awhile in case the fire restarts.

4. How to Use Wheeled Extinguishers- To operate the wheeled extinguisher, open the valve on the nitrogen first. Opening the valve forces the dry chemical through the hose to the nozzle. The person operating the wheeled extinguisher can then control the discharge from the hose by adjusting the nozzle operating valve.

This method for approaching the fire and putting it out is the same as the method used with the hand-held extinguisher: use a sweeping motion and direct the dry-chemical stream to about 6 inches ahead of the flame edge.

b. Rock Dust- Rock dust is a fire-extinguishing material which is readily available in most areas of the mine. Rock dust is used to smother fires by eliminating the oxygen from the fire triangle. Rock dust can be used on Class A, B, and C fires.

Rock dust is best used to fight a fire by shoveling it onto the fire or by throwing it on the fire by hand.

Note: Although rock-dusting machines are usually available in the mines, they should not be used when a fire is involved because the machines generate air to disperse the rock dust. The dispersed air from these machines can move over the fire area fanning the fire and increasing its intensity.

c. Water- Water can be used to extinguish Class A fires. Water acts to cool the

fire, removing heat from the fire triangle.

In most mines, the water which is needed to fight underground fires

can be obtained from two sources: waterlines and fire cars.

1. Disadvantages of water

Water should not be used to control a B or C fire.

Inadequate pressure or too high pressure

The volume of water can be restricted to the length of water lines and hoses (frictional loss- 1/2 lbs. for every ten feet of 1 1/2 inch hose).

The fire nozzle can clog to non-filtered materials in the lines.

Hydrogen can be produced by applying water to super hot fires.

2. Waterlines- In highly productive working sections of the mine (mining over 300 tons per shift) that do not have portable firefighting equipment, waterlines are required.

Therefore, to fight a Class A fire, where a waterline is available in the mine, hook up the fire hose to the waterline.

a. Nozzles

Many mines use fixed nozzles that limit the amount of water to be used
Volume not pressure will put out the fire
Nozzles in the mine today may not handle the high water pressure and may blow out

b. Hoselines

Any hoseline under 2 inch diameter will have frictional loss
Hoselines must a bursting pressure at least 4 times the mine's outlet pressure
Multiple walled hoses should only be used
Proper deployment and storage of hoseline will determine if firefighting efforts are successful

c. Types of nozzle streams

3. Fire Cars- Fire cars (or water or chemical cars) are available in some mines. These cars may be mounted on tires or flanged wheels, and they can be pushed or pulled to the fire area.

The components of a fire car can vary. Some fire cars have a water tank, a pump, or a hose. Others contain a great selection of firefighting equipment such as water, large chemical extinguishers, hand tools, brattice cloth, and rock dust.

4. Fire Cars with Low-Expansion Foam- Some fire cars contain a foam agent which can be hooked onto the water hose along with a special foam nozzle to produce a low expansion foam. The foam works to extinguish the fire by smothering and cooling it simultaneously.

Low-expansion foam is very wet and very heavy and can only be used by a fire fighter who is close enough to the fire to force the foam directly on it. Low-expansion foam does not move down the entry like high expansion foam does.

5. Techniques for Applying Water to Fires- The best way to fight a fire with water is to aim the water stream directly at the burning material.

Use a side-to-side sweeping motion to wet the entire burning surface. Where possible, break apart and soak any deep-seated fires and stand by to extinguish any remaining embers.

There are several different types of water nozzles available for the hose. Some nozzles produce a solid stream of water, some produce a fog spray, while others are adjustable like a garden hose.

Solid-stream nozzles are the best ones to use if it is necessary to project water a long distance to the fire.

d. High-Expansion Foam

1. Description- High-expansion foam is mainly used to contain and control fire by eliminating two points of the fire triangle: oxygen and heat. The great volume of the foam also smothers and cools the fire at the same time.

High-expansion foam is used only in fighting Class A or Class B fires. Since the foam is light and resilient, it can travel a long distance to a fire without breaking down (unlike low expansion foam which is used directly on the fire).

Therefore, this foam is very effective and is used to control stubborn localized fires which cannot be approached at a close range when there is too much heat or smoke, or when the fire is spreading rapidly.

Firefighters can be 500 feet from the fire and in some cases, up to 1500 feet away from the fire when using high-expansion foam.

High-expansion foam is normally used to control a fire. When conditions permit, then fire fighters can be sent in to fight the fire more directly.

a. Types of foam

Protein

Animal protein from entrails or blood (Class A & B fires)
Burn back protection, not film forming, adheres well to roof

Fluoroprotein

Animal protein with fluorinated surfactants (Class A & B fires)
Burn back protection, film forming

Aqueous Film Forming Foam (AFFF)

Synthetic (Class A & B fires)
Burn back protection, film forming

Alcohol Type Concentrates (ATC)

Used mainly in alcohol based liquids (Class A & B fires)
Burn back protection, film forming

High Expansion Foam

Special detergent concentrate, expands 1000 times its own volume (Class A fires)

No burn back protection, not film forming

Note: It is recommended that teams do not travel through foam-filled areas because hearing is impaired, vision is blocked, and breathing is difficult. There is the added hazard of slipping and falling in the foam. Some manufacturers recommend that personnel do not wear self-contained breathing apparatus, gas masks, or other breathing apparatus into the foam.

In cases where teams must travel through foam, team members must use a link-line to ensure team members do not get lost in the foam. The team should travel along the track or rib where the best footing is likely to be.

Consequently, before entering a foam-filled area, teams should clear away as much foam as possible. One of the best ways to do that is to use a solid stream of water to knock down the foam and clear the area.

2. Foam Generators

a. Description- Foam generators are portable and come in a variety of sizes which have different foam-producing capabilities. The smaller models can be hand-carried by two people or wheeled into position. Other larger models can be mounted on rubber tires or can be transported on a track-mounted mine car.

There are water-driven models of foam generators or diesel- or electric-powered models. The water-driven models produce foam from a water-detergent mixture which is pushed by the water pressure through nylon netting or screen. As in other models, a blower fan produces the bubbles and pushes them out of the generator.

b. How to Use- There are different methods to use foam to fight a fire as described below.

1) The foam generator is positioned outby the fire and the plastic tubing is attached to the foam outlet. The plastic tubing is designed to unroll as the foam passes through it leading the foam directly to the fire area.

2) Create a confined area where foam can be pumped onto the fire to completely fill or plug the fire area. Build a stopping with an opening in it for the foam generator to fit into the opening outby the fire.

Set up the foam generator at the stopping opening and brace it or fasten it down if possible. After it is set up, the generator can be started and foam can then fill the area. Sometimes plastic tubing is attached to the foam generator to direct the foam to the fire area.

In some situations, a team can use the generator in stages, moving it closer to the fire as the fire is brought under control. Before traveling through a foam-filed area, knock down the foam with water to clear a safe passage.

IV. Firefighting

a. Before Going Underground- Rescue teams should be aware of two main dangers before going underground:

1) Spreading of the fire and

2) Explosions.

Before going underground, the team should make sure that: 0 The main fan is running;

A guard is monitoring the operation of the fan; and

Tests are being made at main returns for any mine gases.

It is important to monitor the levels of oxygen, carbon monoxide, and any explosive gases.

Ventilation should always be continued through the mine during a fire in order to carry off explosive gases and distillates away from the fire area, and to direct the smoke, heat, and flames away from the team.

Note: Do not make any sudden changes to the mine ventilation. If the main fan is off or destroyed, the command center will have to decide what to do before starting the fan. Remember, everyone should be out of the mine before the fan is started.

Before going underground, the team should know about the following:

1) Know ignition sources such as battery-operated or diesel equipment.

2) Know underground storage areas for explosives, oil and grease, or oxygen or acetylene cylinders in or near the affected area; and

3) Cut off electrical power to the affected area. Arcing from damaged cables can ignite and cause additional fires or explosions. Remember, once the power is cut off, power is lost for any underground auxiliary fan, and to any other electrically powered equipment, such as a pump in the area. Losing the pump can result in major flooding.

While most of the above conditions and information should be available to the team at the briefing, some specific information about what is in or near the affected area, and what equipment was left energized, can only be determined by the exploration teams as they advance.

Note: For safety reasons, before and after firefighting, each team member should have a carboxi-hemoglobin test to determine how much carbon monoxide (CO) is in the bloodstream. A small amount of blood is drawn for this test to detect the presence of CO in the blood. Each team member's on-site CO rate should be compared to the base rate obtained during each person's annual physical examination to determine if dangerous levels of CO are present. If a team member has absorbed too much CO, he or she should not be allowed to reenter the mine until his or her CO level is reduced.

b. Locating Fires and Assessing Conditions- The two main objectives of mine exploration work during a mine fire are:

Locating the fire, and

Assessing the conditions in and near the fire area.

Once the conditions are known and reported to the command center, the officials there can then decide how the fire should be fought.

The command center has to be given the basic information about the fire: where it is, what is burning, how large it is, and what conditions are near the fire area.

Before the team enters the mine, there may be some information available about the location of the fire. Miners who were working in the area may have reported seeing smoke or flames before evacuating the mine. Their reports would help the team pinpoint the fire and its magnitude.

Detecting carbon monoxide or smoke coming from the main fan or main return are obvious indications that a fire exists.

Having a laboratory analysis of air samples taken from the main fan or return give an accurate analysis of the gases which are present and can indicate what is burning. The amount of carbon monoxide found in the samples can indicate the magnitude of the fire.

Certain information is only obtainable from the rescue teams during mine exploration. The teams can pin point an unlocated fire and assess its magnitude by reporting where and how dense the smoke is, and by feeling the stoppings and doors for heat.

If a team encounters a small fire during exploration, it can be extinguished by hand-held fire extinguishers, rock dust, or with water from a nearby waterline. But dealing with large fires requires more equipment and careful planning.

The team is to gather as much information about the conditions in and around the fire area as possible and report it to the command center in order to keep officials up-to-date on conditions.

During mine exploration during a fire the team should:

Take gas readings in the returns near the fire area to check if the atmosphere is potentially explosive;

Check the ventilation controls and report their condition since it is likely that some damage will occur to the controls during a mine fire; and

Test the roof and the ribs in the fire area because heat from a fire wiII weaken them.

Once the command center has this information it will have sufficient facts about the fire and what is needed to extinguish or control it, and whether to fight it directly or seal the mine.

Use of Tricket's ratio- This formula can be used in certain situation if the gas readings are exact as they can be.

This formula should not be used if the air intake is oxygen deficient.

Tr = CO2 + 0.75 CO - 0.25 H2

0.265 N2 - O2

The gas samples needed for the formula to work are carbon dioxide, carbon monoxide, hydrogen, nitrogen and oxygen.

Once the formula is worked, the answer should tell you if the following is burning:

Tr < 0.4 - Generally indicates no fire because:

Sample gases are residual rather than active fire gases or
Result from oxidation without important heating

Tr = 0.45 - .05 - Methane is burning

Tr = 0.5 - 1.0 - Coal, oil conveyor belting, insulation, or polyurethane foam

Tr = 0.9 - 1.6 Wood

Tr = > 1.7 Error

c. Direct Firefighting

1. General Procedures- To fight a fire directly means that an extinguishing agent is put directly on the fire to put it out. To do so means the firefighters have to get very close to the fire for them to use fire extinguishers, water, rockdust, or foam to put out the fire.

Always approach a fire from the Intake side if possible when fighting the fire directly. This approach ensures the smoke and heat are directed away from the fire fighter.

Use wide angle fog for team safety and steady steam for direct contact with fire.

Should the fire back up against the intake air in search of oxygen, put up a "transverse" brattice from rib to rib but leave an open space at the top. Doing so will cause increased airflow at the roof and slows down. the progress of smoke and flame into the air current.

Take caution in putting up the brattice. The brattice should cover about one-half to two-thirds of the area from the floor to the roof or top. Do not run the brattice too high or it will cut off the airflow over the fire which could result in an explosion.

If heat, smoke, and ventilating current allow, water is the best means of fighting a fire, provided it is not an electrical fire. However, there has to be a sufficient water supply, water pressure, and available lengths of hose to reach the fire.

In situations where the team finds it impossible to approach the fire for direct firefighting, foam or water can be pushed over the fire area to slow down the fire sufficiently. This method allows the team to get closer to the fire to fight it more directly.

2. Hazards- During direct firefighting, there are certain hazards to the team. These hazards include electric shock and electrocution, toxic and asphyxiating gases, oxygen deficiency, explosive gases, heat, smoke, and steam.

a. Electric Shock and Electrocution- Electric shock and electrocution are the primary hazards to fire fighters using water, foam, or other conductive agents to fight a fire. It is for this reason that it is strongly recommended that the power to the fire area be cut off regardless of the type of fire. Cutting off the power not only eliminates the electrical hazards, but also eliminates the possible hazards to any electrical components that could be involved.

b. Toxic and Asphyxiating Gases- There are several toxic and asphyxiating gases which fire fighters should be very cautious of and be certain to wear SCBAs in mine atmospheres where these gases may be present:

Note: If the mine fan stops or slows down, the fire team should leave the fire area. If the fan continues to run slowly or remains stopped, teams and underground personnel should leave the mine entirely before the fan is restarted.

The mine fan should never be stopped or reversed while teams are underground. Doing so forces unburned distillates from the fire to travel back over the fire area, increasing the magnitude of the fire.

If any explosive concentration of gas is detected in the return air of the fire, all teams and any other personnel should leave the mine immediately.

c. Heat, Smoke, and Steam- Heat, smoke, and steam are other hazards underground rescue teams face. These hazards determine how close a team can get to a fire and how long the team can work. Working in these conditions can be extremely uncomfortable.

Smoke limits visibility and causes disorientation. Walking can be dangerous because it is difficult to judge your position in relation to surroundings. This lack of orientation can cause a member to lose his or her sense of balance and fall and get injured.

Working in hot and steamy atmospheres can cause exhaustion and stress the body's system, particularly when working hard.

Heat can weaken the mine roof in the fire area, especially in mines where head coal is left in place. To protect against a weak roof, always test the roof near the fire area frequently and bar-down any loose material.

Remember, during firefighting, smoke and steam are less dense near the mine floor but are more dense at the mine roof. Keep adequate ventilation over the fire area to carry off smoke, heat, and steam away from the team.

As stated earlier, if the fire begins to back up against the flow of the intake air in search of oxygen, put up a transverse brattice from rib to rib, leaving an open space near the roof. Doing so should slow down the progress of the smoke and flame into the intake air current.

d. Indirect Firefighting-

in some instances, fighting a fire directly is ineffective or not possible because of the presence of certain mine hazards such as high temperatures, bad roof, or explosive gases.

Under these circumstances, it may be necessary to fight the fire from a distance, or fight the fire "indirectly," by sealing the fire or by filling the fire area with foam or water.

The indirect methods work by excluding oxygen from the fire. The foam or flood of water also serves to cool the fire.

Sealing Underground

a. Planning- The purpose of sealing a mine fire is to contain the fire to a specific area and to exclude oxygen from the fire and eventually smother it. Sealing can also be done to isolate the fire to allow normal mining operations to resume in other areas of the mine.

Sealing mine fires underground is complex with no set rule of procedures to follow. Many factors have to be considered to determine the methods to be used for the eventual success of the sealing operation.

b. Temporary Seals- There are two types of seals: temporary and permanent. The temporary seals are put up before permanent seals. Temporary seals are erected in order to seal of f a fire as quickly as possible. Usually permanent seals are then constructed outby the temporary seals to seal off the fire more effectively.

Temporary seals are built to be fairly airtight, and are usually constructed of brattice cloth, concrete blocks, or boards.

Permanent seals are built to be much stronger and more airtight than temporary seals. They are notched into the roof, ribs, and floor to make them sturdy to withstand the force of an explosion, should one occur.

Permanent seals are usually built with concrete blocks and strong mortar. They can be made of poured concrete, wood, or plaster, or pack wall of various kinds as well.

Command center officials decide what types of seals are to be erected based on all of the information they receive pertaining to the mine fire.

The command center must consider all dangerous mine conditions when planning to seal a mine fire. The following six factors are of primary concern.

1) The volatility of the coal seam. High-volatile coal seams burn much faster than low- or medium-volatile coal. Sealing a fire that involves high-volatile coal is often necessary because fighting the fire directly is very difficult.

2) The amount of methane liberated by the coal seam. As the amount of methane increases underground, the potential for explosion increases.

3) The location of the fire and the area involved. These two elements determine the number of necessary seals and where they should be placed.

4) The presence of head coal and the composition of roof strata. Mines which have head coal left in them will have a fire spread more rapidly than those that don't. Certain roof strata is greatly weakened by fire and heat, and may be too hazardous for the rescue team to work under.

5) The availability of construction materials and the means of transporting them to the sealing sites. This factor affects the type of temporary or permanent seal to be built. Frequently in emergency situations, temporary seals are built with readily available materials.

6) The building sites for the seals. These sites are determined by the location of the fire, how fast the fire is spreading, the ability to control ventilation in the fire area, the gas conditions present, and the volatility of the burning coal seam.

Fires involving high-volatile coal are often sealed more than 1,000 feet away from the fire. Fires involving low-volatile, non-gassy coal may be sealed relatively close to the fire.

One of the reasons why seals should be erected as far as possible from a high-volatile coal fire (1,000 feet or more) is to allow sufficient time for the mine rescue teams to leave the mine before an explosive mixture of gas is likely to form inby the seals.

The command center decides the approximate location for building the seals, what material to use, and in what order the seals must be built if more than one seal is to be erected.

The mine rescue team chooses the exact site within the designated entry or heading for building each of the seals and is to construct them well.

When choosing an exact site for temporary seals, the site should have:

A good roof, and

Even roof and rib surfaces.

When building a temporary seal, it should always be built far enough into the entry or crosscut to allow enough room and good roof outby it for a permanent seal to be built. If the only site available for sealing has bad roof, it may have to be barred down and supported with posts prior to building the seal.

1. Types of Temporary Seals

a) Brattice Cloth- There are three ways to erect brattice seals:

1) The brattice, canvas, or plastic can be attached to the roof and ribs with spads. The surplus brattice at the bottom is then weighted down with timbers or other available loose material to keep the seal closed.

2) The other two methods require nailing the brattice to a framework of posts and boards that are set in a solid and well-squared location. One style involves cutting and nailing the brattice to the frame work and to the ribs, if possible.

It may be necessary to double or triple the thickness of the materials in order to improve the effectiveness of the seal. To seal the bottom as well as possible, shovel loose coal or other material along the bottom of the seal. Doing so provides a seal which is tight enough for most purposes.

3) If time allows and a tight seal is required, a more substantial brattice cloth seal can be erected. To do so, set posts about 1 foot from each rib, and one or more posts in between. Set the posts firmly on solid ground.

Nail boards across the top, the center, and the bottom of the posts. The boards should extend from rib to rib, and the top and bottom boards should be placed as close to roof and floor as possible.

If the ribs are irregular, short boards extending from the top to the center boards, and from the center to the bottom boards should be nailed along both sides of the frame work. These boards should follow the curvature of the rib.

A piece of brattice cloth, canvas, or plastic should be nailed to the boards. The material should be cut with enough room to cover the opening, allowing for extra material on the sides, top, and bottom. It may be necessary to double or triple the thickness of the material in order to improve the air tightness of the seal.

To close small openings around the edges of the seal, small pieces of boards should be used to push the brattice cloth into all irregularities of the roof, ribs, and floor and nailed into place.

To obtain maximum tightness, it may be necessary to caulk the edges of the seal, and to shovel loose coal or other material against the bottom.

If reasonable care is used, a brattice cloth seal can be constructed which will allow only a slight leakage of air.

b) Concrete Block- Concrete block seals can be erected quickly, especially if they are laid dry. To lay them dry, the blocks should be built up on a solid bottom, one layer at a time. The last layer of blocks should be wedged between the top of the seal and the roof.

Caulk the edges of the seal with cement or other suitable caulking material. Then plaster the seal with cement or another suitable sealing material to make the seal as airtight as possible.

c) Wood- Various kinds of boards can be used to construct wood seals. Usually rough boards of various widths and approximately 1-inch thick are used. If a tighter seal is desired, it is better to use tongue-and-groove boards or shiplap boards.

Nail the boards horizontally on a frame work of ribs and center posts. The posts should be wedged inward and hitched in the bottom. If possible, a shallow hitch should be dug in the roof, ribs, and floor, and the boards should be fitted snugly into the hitch as the seal is erected.

The boards can be overlapped at the center of the seal if they are too long to fit properly. Overlapping them will eliminate having to saw the boards, which saves time.

If using shiplap boards, nail them onto the framework, starting from the top and overlapping each board while working toward the bottom. After the boards are nailed to the framework, caulk the edges of the seal with cement or other suitable caulking substance.

If using rough lumber and sufficient brattice cloth is available, cover the entire surface of the seal with a layer of the cloth. If brattice cloth is not available, plaster over the cracks and holes to make the seal airtight.

2. Considerations While Building Temporary Seals

a) Air-Sampling Tubes- When building temporary seals, include provisions in some of the seals for collecting air samples from within the sealed area. Pipes with valves are used for this purpose. These pipes are usually quarter-inch copper tubing because it is light and flexible.

This air-sampling tube can be placed anywhere in the seal, and should extend at least to the second crosscut inby the seal in order to get a good representative sample of the air which is close to the f ire. Depending on the situation, it could vary from 40 to 100 feet. The tube can be suspended from the roof by tying it to timbers or roof bolts.

The number of seals in which air-sampling tubes should be placed depends on the sealed area, the number of seals, and their positions.

b) Ventilation- When building temporary seals, consider ventilation. Be sure there are no abrupt changes in ventilation over the fire area.

A steady flow of air must continuously move over the fire to carry off explosive gases, distillates, heat, and smoke away from the fire.

The only way to keep the air flowing over the fire area is to leave one intake airway and one return airway unsealed while the other airways are being sealed.

Then as a final step, the last intake and return can be sealed simultaneously. This method enables the ventilation to continue over the fire area until both seals are completed.

Occasionally two teams are used to simultaneously seal the last intake and return. In such circumstances, the teams should be in constant communication between themselves or with a coordinator in order to synchronize the simultaneous construction.

Usually fires are sealed far enough away from the fire in order to keep the heat and pressure in the sealed area from affecting the seals.

In some cases though, the only site available for sealing a fire is close to the fire area where the heat and smoke are very intense in the returns. As a result, the mine rescue teams will not be able to work in the returns for very long.

In this type of situation, the fire can be systematically sealed to protect the team as much as possible from the heat and smoke in the returns.

When the intake seal is finished, the pressure will be reduced in the returns and the brattice curtain can be dropped immediately by the rescue teams, spadded to the ribs and weighted at the bottom-all within a few minutes. The teams then immediately leave the mine.

If, for some reason, the seals do not hold because of the heat and pressure within the sealed area, the fire will have to be resealed further away from the fire.

c) Explosion- If an explosion is likely to occur after the seals have been erected, arrangements should be made to close the last seals after all personnel are out of the mine. This can be done by leaving hinged doors (similar to drop doors) that will close automatically in one or more of the seals; usually it is the last intake seal to be erected.

These doors can be temporarily held open with a counterbalance in the form of a perforated bucket filled with water. The holes in the bucket should be made to allow sufficient time to elapse before the water drains from the bucket. Using this device allows enough time for the personnel in the mine to reach the surface before the door or doors close to complete the seals.

When fires are being sealed in gassy or dusty mines, it is essential to apply a thick coating of rock dust to the ribs, roof, and floor of entries, and to crosscuts for several hundred feet outby the seal, and if possible, inby the seal. In the event of an explosion around the fire, there will be less chance of propagating a coal-dust explosion.

d) Isolation- It is important to isolate the sealed area from the mine in as many ways as possible. All power cables and water or air lines entering the sealed area should be removed or severed from the sealed area. Removing a section of rail from the track and a section from any other conductor leading into the sealed area is advised also.

3. Permanent Seals- A mine cannot be returned to production until the sealed area of the mine has been closed off with permanent seals. After temporary seals are erected, the usual waiting period of 72 hours is recommended before beginning construction on the permanent seals.

a) Types of Permanent Seals- Usually permanent seals are built with solid concrete blocks, although other material may be used. When building seals with

concrete blocks, mortar is used in between them, and the entire front of the seal is plastered over. Urethane foam can be put around the edges to seal any leaks.

Urethane foam is an effective sealant around the perimeter of the seal, but should never be applied more than an inch thick because the potential for spontaneous combustion increases with greater thicknesses.

All permanent seals should be well-hitched in the roof, floor, and ribs to make them as airtight as possible.

The type of permanent seals used for sealing a mine fire depends on:

The type of materials available;

The length of time the materials are to be used; 0 The necessity for complete airtightness; and
The strength required to withstand pressure or crushing. Permanent seals must be very well built to withstand the outward pressure on them, which can be very substantial.

b) Considerations While Building Permanent Seals

1) Isolation- When erecting permanent seals, the area inby the seals is to be isolated from the rest of the mine. All cables, lines, and track which were removed or severed. For the temporary seal must also be removed or severed for the permanent seal.

2) Air-Sampling Tubes- The permanent seals must have provisions for collecting air samples from within the sealed area.

If air-sampling tubes were installed in the temporary seals, it will only be necessary to extend those tubes and valves to the permanent seals if they do not already reach.

4. Taking Air Samples- After the fire area is sealed, it may be necessary to take air samples of the air behind the seal to assess the quality of the air. The best time to do so is when the sealed area is under positive pressure or "breathing

out.

Pressures within and without sealed areas will vary according to temperature and barometric pressure changes. There are three general descriptions for these differences in pressure:

1) "Breathing in", or a negative pressure in the sealed area;

2) "Breathing out," or a positive pressure in the sealed area; and

3) "Neutral," when there is no difference in pressure in the sealed area.

When collecting an air sample, if the sealed area is breathing out, let the pressure evacuate the air from the sealed area for awhile before getting the sample. By doing this, it assures getting a good representative sample of the air that is in the fire area and not getting the air that is right next to the seal.

If the sealed area is breathing in or neutral, use an aspirator bulb or a small pump to evacuate enough air from the sealed area to assure collecting a good representative sample of the air that is in the fire area.

Sometimes though seals are situated so far away from the fire that the air near the seals has a completely different composition from the air near the fire. In these cases, air samples are usually not collected at the seals because they will be inaccurate. Instead, use a 2-inch borehole from the surface to the fire area to obtain air samples.

5. Sealing the Surface

a) Entire Mine- Although it may be possible to seal a fire in a gassy section of a mine without a subsequent explosion during or shortly after sealing operations, undoubtedly the safest method is to seal the mine openings at the surface. On these occasions, any mine opening to the surface is plugged up and sealed as best as possible.

b) Remote Sealing- Another method of sealing a fire from the surface is to pump sealing material down through the boreholes to the fire area. This method is usually used within a mine which was already sealed on the surface, making it possible to establish effective temporary seals in a distant part of a large mine where a fire raged.

By establishing these temporary seals, it may be possible to reestablish ventilation throughout the rest of the mine without disturbing the fire area during the initial recovery of the mine.

Some of the materials which can be pumped through the borehole to seal the fire area are rock wool or fly ash.

6. Foaming the Fire Area- Foam can be used indirectly on a fire in an attempt to bring the fire under control allowing more direct extinguishing methods to be used.

In these instances, the foam generator is setup some distance from the fire. The foam is then pumped down to the fire to smother and cool it.

Sometimes it is necessary to construct a temporary stopping around the foam generator which will create a confined area where the foam can be pumped.

When conditions permit, the foam generator can then be moved closer to the fire, or the team members can move in to fight the fire directly.

7. Flooding the Mine- One additional method for indirect firefighting is to flood the sealed area with water. This method is infrequently used. Rather, it is used as a last resort because flooding the mine makes recovery of the mine very difficult and expensive.

Another application is the use of liquid nitrogen which can be injected through boreholes into the fire area to make the mine atmosphere safe during firefighting activities while permanent seals are being built. Injecting nitrogen in this manner is done to make an inert mine atmosphere to reduce the chance of an explosion and the buildup of methane. It also cools the area.

Nitrogen is often used for spontaneous combustion problems since methane is most explosive from 5 to 15 percent in a 12 percent air mixture. Carbon dioxide can also be used following the same principles and applications as nitrogen.

The company brings in its own technicians, plus union (where applicable), state, and federal experts who jointly decide if nitrogen or carbon dioxide should be used.

V. Explosions

a. Causes and Effects- Explosions are very similar to fires in terms of their cause. Just as there are three elements required to cause a fire (recall the fire triangle), three elements must be present for an explosion to occur. Those elements are:

Fuel,

Oxygen, and

Heat (ignition).

The fuel for an explosion can be an explosive mixture of gas, or a sufficient concentration of coal dust, or a combination of both of them.

Like a fire, an explosion can only occur if all three elements are present at the same time. To avoid an explosion, the three elements of the fire triangle must be kept away from each other.

The most frequent cause of explosions in coal mines is the ignition of methane gas, coal dust, or a combination of the two.

The source of ignition is commonly sparks, an electric arc, an open flame, or the misuse of explosives.

Explosions can cause extensive mine damage. Explosions can blow out roof supports, damage ventilation controls, twist or scatter machinery, and ignite numerous fires. Roof and ribs can be weakened, and fires can be spread.

Once an explosion occurs, there is the chance of more explosions. Further explosions are possible because the ventilation system is damaged from the first explosion. Methane can accumulate and ignite either from existing fires which may have started, or from other sources, such as an arcing or damaged cable.

The coal dust which was stirred up from the first explosion can prompt additional explosions.

Coal dust explosions travel at a speed exceeding 3000 ft. per second

b. Before Going Underground- Before going underground to explore a mine where an explosion has occurred or is suspected to have occurred, the rescue team should make sure that:

The main fan is running;

A guard is monitoring the operation of the fan; and

Tests are being made at the main returns for any mine gases.

Rescue teams should be aware of the same types of hazards they prepare for to explore a mine where an explosion occurred as they do to prepare for a mine where they must fight a fire. These preparations are reviewed below.

1. Keep the main fan running to prevent a build up of explosive gases and assure ventilation at least up to where underground controls were damaged or destroyed by the explosion.

Testing for CO and explosive gases in the returns is essential to perm it teams to withdraw from the mine if a dangerous situation develops.

2. Cut off power to the affected area. Arcing from damaged cables can ignite and cause more explosions or fires. Remember that cutting the power will affect any auxiliary ventilation which will affect the operation of any electrically powered equipment, such as the pump. The command center will have to consider these factors.

3. The team must know of any possible ignition sources underground, including any battery-powered or diesel equipment left running. Any fires which develop are also ignition sources for more explosions.

4. Teams should know of any underground storage areas for explosives, oil and grease, or oxygen or acetylene cylinders.

The teams should be given this information during their briefing, but more specific information can be gathered by the teams as they advance through the mine during exploration.

c. Exploration: Indications of Explosion and Assessing Conditions- Frequently an explosion is suspected to have occurred in a mine, but officials can't know if that is true until the mine exploration team assesses mine conditions firsthand. What may seem like an explosion may turn out to be a major roof fall or a rock burst or a rock bump.

The first indications that an explosion took place may be from reports from miners in nearby sections who felt a sudden movement of air, noticed smoke or dust in the air, or heard the sound of an explosion. A jump in the pressure recording chart for the main fan would be an indication too.

Rescue teams going into a mine to check for an explosion should look for the following evidence:

· The presence of afterdamp and toxic and explosive gases in the main returns.

· Blown out stoppings and roof supports. Examine damaged stop-. pings carefully. The direction in which a stopping has blown indicates the direction of the force of the explosion. If stoppings are not destroyed, note if blocks have moved, especially when stoppings cross entries near intersections. (The movement of blocks from stoppings in crosscuts is seldom significant.)

Overturned equipment.

Evidence of coking and coke streamers and their size. (Coke is produced when coal is burned in the absence of oxygen under extremely high temperatures.)

Roof falls.

Coal dust or soot on rock-dusted surfaces. (Maybe the first evidence of an explosion that occurred inby that point.)

Film of dust on mine rail (for the same reason).

Smoldering fires and scorched material.

The initial role of the rescue team after an explosion is usually to explore and assess conditions. After that is completed, the teams begin to restore ventilation and recover the mine.

In some situations it may be too dangerous for teams to explore and re-ventilate safely. If that is the case, teams are usually instructed to seal the area.

Section 7

Mine Recovery

Table of contents

Introduction
Assessing conditions
Reestablishing Ventilation

Unsealing a fire area

When to unseal
Preconditions
Preparations
Methods

Progressive ventilation
Direct ventilation
Gas buildup

Clearing and rehabilitating the area

Roof and rib control
Pumping water
Clearing roadways and track
Loading out falls and hot debris
Restoring power
Reestablishing communications

I. Introduction

The main objective of recovery work is to return the mine or the affected area of the mine to normal operations after a mine disaster as soon as conditions permit.

Recovery operations can span from a few days work to restore ventilation to a section, to many months of work, to restore ventilation and rehabilitate the entire mine, depending on the amount of recovery work that will be required. Naturally it will take more time to restore ventilation throughout the mine than it would to restore ventilation in one section.

The role of a rescue team member in recovery work varies as the operation progresses and conditions change.

Until ventilation is restored in the affected area, apparatus crews will be needed to assess conditions, rebuild stoppings, clear debris, and stabilize the roof and ribs where necessary.

Once the ventilation is restored and fresh air is advanced, non-apparatus crews can then resume the rehabilitation and cleanup effort.

II. Assessing Conditions

In order to plan a recovery operation, there must be an assessment of underground conditions initially. Then as the work progresses, rescue teams will make updated reports on the conditions and damages they encounter.

Assessing conditions is necessary for the safety of the rescue teams, and it also determines how much rehabilitation work is needed to recover the affected area.

One of the most important areas the rescue team will check is tie ventilation system and what damage it has sustained. All ventilation controls and auxiliary fans and tubing will need to be examined.

As the team explores and restores ventilation to the sections, gas conditions, as well as roof and rib conditions, will need to be checked thoroughly.

Track, waterlines, power lines, and phone lines must be investigated for any evidence of flooding, flood damage, smoldering debris, or hot spots in a fire area.

Ill. Reestablishing Ventilation After a Fire or Explosion

Restoring ventilation and returning fresh air to a mine area damaged by fire or explosion is the main task of the mine rescue teams in a recovery operation. Once this is accomplished, regular work crews can help with the recovery effort.

If the fire area was sealed, it means unsealing the area, assessing the damage, and repairing and rebuilding the ventilation system.

If the area was not sealed, the job of reestablishing the ventilation is considerably easier. It involves merely assessing the damage and making the necessary repairs to restore normal ventilation.

In an area which has been damaged by an explosion, the task is the same as it is after a mine fire: to assess the damages and to repair the ventilation controls. After an explosion, a great deal of construction work is usually needed to restore ventilation to its proper function.

a. Unsealing a Fire Area- Unsealing a fire area requires careful planning. To open the seals prematurely could cause an explosion or reignite the fire.

Usually a detailed plan is prepared by company officials, with the, advice of federal, state, and union representatives (when applicable) for unsealing a fire area.

Although mine rescue teams do not plan the unsealing operation themselves, it is important for the teams to know what the considerations and options are, as well as the potential problems in unsealing the mine.

1. When to Unseal- Determining the exact time to unseal a fire area is based on the laws of physics and chemistry, plus experience and good judgment.

A fairly accurate analysis and interpretation of the gases present in the sealed area is possible through the proper sampling techniques and with the assistance of a chemist experienced in mine recovery.

Gas conditions and other factors must be evaluated when choosing the safest time to unseal a fire area.

The main factors governing the time for unsealing a fire area are:

1) The extent and intensity of the fire at the time of sealing.

2) The characteristics of the burning material and surrounding strata.

3) The tightness of the seals.

4) The effect of the barometric pressure on the enclosed area.

5) The effect of temperature on the enclosed area.

6) The location of the fire area with regard to ventilation.

7) The gas conditions as indicated by analysis of the air samples taken from behind the seals. Usually the gases analyzed include: oxygen, carbon monoxide, carbon dioxide, methane, hydrogen, and nitrogen.

2. Preconditions for Opening a Sealed Fire Area

No attempt should be made to unseal a fire area until:

1) The oxygen content of the air behind the seal is low enough to make an explosion impossible (no matter what the quality of the combustible gases is behind the seal);

2) Carbon monoxide (the gas which indicates combustion) has diminished or disappeared from the air behind the seal; and

3) The area behind the seals has been given enough time to cool so when air is again introduced during the unsealing operation, it will not rekindle the fire.

Achieving these goals may be difficult and may require a great deal of time.

3. Preparations for Opening a Sealed Fire Area

Opening a sealed fire area requires specific preparations:

1) Adjustments in ventilation should be made so that toxic and explosive gases released from the sealed area are directed into the main returns.

2) Someone should monitor the operation of the main fan to ensure it is operating correctly. If the fan slows or malfunctions, the teams working underground should be withdrawn at once. Gas levels at the main returns should be monitored also.

If the fan is electrically driven, precautions should be made to prevent explosive gases from coming in contact with the fan motor or any other electrical equipment used to operate the fan.

3) Make checks to ensure that all electrical power in the sealed area was cut off before the unsealing process is begun. Power in the return airways near the sealed area should be locked out.

4) In bituminous coal mines, all entries and crosscuts leading to and from the sealed area should be heavily rock dusted, and this should be done for a considerable distance outby the seals to be opened.

5) Withdraw all unnecessary personnel from the mine.

4. Methods of Unsealing Fire Areas

There are two basic methods for unsealing a fire area: progressive ventilation and direct ventilation.

Progressive ventilation is the reventilation of a sealed area in successive blocks by means of air locks. Progressive ventilation is the most common method of unsealing a fire area in coal mines. The advantage of progressive ventilation is that gas conditions can be carefully controlled, and the operation can be stopped at any point if conditions become hazardous. The disadvantage of progressive ventilation is that it is a slow process.

Direct ventilation is the reventilation of the entire sealed area done at once. With direct ventilation, recovery is accomplished quicker than it is with progressive ventilation, but gas conditions are less controlled. Before using direct ventilation, there should be conclusive evidence that the fire was extinguished.

Direct ventilation must be used to recover mines that have been sealed on the surface.

a) Recovery by Progressive Ventilation- Progressive ventilation is the usual method of recovery in these situations:

When the sealed area is large;

When the fire is extensive; or

When bodies must be removed.

With progressive ventilation, the sealed area is explored and reventilated in successive blocks by the use of air locks. As long as the conditions remain favorable, the work can continue and the entire area can be recovered.

Rescue teams are reminded that air locks are two stoppings built approximatelylOtol5feetapart. Each stopping should have a door or flap in it permitting teams to enter and exit the sealed area. One opening in the air lock must be kept closed while the other is open to prevent the two atmospheres from mixing.

Note: Air locking operations should never be undertaken until the oxygen content of the air behind the seals has been reduced to at least 2 percent.

During progressive ventilation, a certain amount of air will enter the area behind the seals, which is unavoidable. But as the work continues, oxygen and explosive gas levels must be carefully monitored, and the operation must be stopped if conditions become dangerous.

Recovery done by progressive ventilation is similar to advancing the fresh air base. It is usually a slower operation, however, because of the damage which is normally found in a sealed area.

The first step in progressive ventilation is to build a stopping at one of the seals on the intake side of the fire area to create an air lock.

Air locking operations should always begin on the intake side of the fire.

Once the air lock is completed and conditions allow for entering the sealed area, a team with apparatus can then enter the air lock and break out an opening in the seal.

Teams may have to wait awhile after removing the first few blocks from a seal to permit the pressure to stabilize.

After the seal is opened, an apparatus team, or if necessary, a rotation of teams can enter the sealed area to explore and assess conditions to the point where the next air lock will be built.

The distance between air locks is generally 200 to 500 feet. The distance between them will depend on the conditions encountered as well as the amount of construction work required to prepare an area for reventilation.

During exploration, the teams should note the general conditions, but in particular, teams should take temperature readings and do the necessary tests for oxygen, carbon monoxide, carbon dioxide, and methane. Air samples should be collected when requested, also.

The team should also take measurements for the new air lock which will be built and for any additional stoppings that will be needed in the parallel entries to seal the area.

Additionally, the team will have to prepare the area between the two air locks for reventilation. This job involves repairing ventilation controls and making the necessary changes to direct the air to a return airway.

Before the team leaves the area being prepared for reventilation, a final check must be made for any possible fires.

After the team is out of the area, it can be reventilated. Usually, a seal on the return side is opened first, followed by one of the seals on the intake side.

The return air should be kept below the lowest explosive limit of methane and oxygen. If conditions are good, the rest of the original seals can then be opened.

This process of putting up air locks and working through them to explore and to reventilate an area can be repeated until the entire area is recovered.

As the work progresses, frequent tests should be made to monitor gas conditions and to determine if the gas conditions in the sealed area and at the end returns of the areas are being recovered since the main concern is the possibility of an explosion or the rekindling of the fire.

Once the work progresses close to the core of the fire, it may be decided to load out the heated materials through the air lock before attempting reventilation.

Once all indications show the fire has been extinguished, then the final sealed area can be reventilated. The gases from this area should be removed as quickly as possible.

b) Recovery by Direct Ventilation- The other method for recovering a seed fire area is by direct ventilation.

In direct ventilation, the affected area is recovered and reventilated as a whole rather than by successive blocks. Therefore, recovery is accomplished faster than by progressive ventilation. However, gas conditions are less controlled.

Before using direct ventilation, there must be conclusive evidence that the fire has been extinguished.

The first step, as in progressive ventilation, is to build an air lock at an intake seal. The apparatus crew can then work through the air lock and enter the sealed area.

The apparatus team, or a rotation of teams, have to take temperature readings and test for oxygen, carbon monoxide, carbon dioxide, and methane. They will probably have to collect air samples too.

Once teams complete their tests and observe the area, they are to return to the fresh air base.

If conditions are favorable, then unsealing can start. A seal on the return side should be broken open and the air lock opened to admit air. Then the area can be reventilated.

Any combustible gases in the main return should be kept to the lowest explosive limit, if possible.

Note: When using the direct ventilation method, be certain that all unnecessary personnel are out of the mine before air Is actually directed into the sealed area. The remaining people needed to open the seals should then come out quickly after the seals are opened.

The command center determines when conditions appear safe to return to the mine.

If the sealed area is extensive, it is advisable that the rescue team wear apparatus to reenter. However, the team should check for and sweep out any standing gases from the fire.

When direct ventilation is used to recover mines which were sealed on the surface, the procedure is basically the same except an air lock is not used.

Just as with underground sealing, surface seals, one on the intake and one on the return, should be opened at approximately the same time. When it is decided that it is safe, then the apparatus teams can explore and begin reventilation.

c) Preventing a Buildup of Gases in the Fan House- If the mine is using an exhausting fan, provisions have to be made to prevent the buildup of explosive gases in the fan house.

One technique used is to ventilate the fan house. An auxiliary fan can be set up a short distance from the fan house with tubing extended into the fan house.

Another technique is to control the volume of air being drawn from the mine. This method can be done by using the explosion doors as a regulator.

b. Reventilation After an Explosion- The objective of restoring ventilation after an explosion is to rid the mine of explosive or potentially explosive gas mixtures and restore normal ventilation and normal amounts of oxygen to all mine workings

1. Considerations- There are three areas of concern to rescue team members and they are listed below.

1) The concentrations of explosive mine gases. Are they within, above or below the explosive ranges?

2) The percent of oxygen present in the mine. Is there sufficient oxygen to support life? Is the amount of oxygen low enough to prevent another explosion?

3) Possible sources of ignition. Are they being considered and eliminated? Possible ignition sources are: electrical power, battery-powered equipment, possible fires and hot spots, and sparks from tools and team equipment.

Note: Teams should check the permissibility of whatever they bring into the sealed area and make sure they use non-sparking tools, spads, and shovels.

During reventilation work, an observer should be stationed at the main fan to ensure it is operating correctly and to warn the team in case of any malfunction. Additionally, someone should be at the main returns to monitor the gas levels.

2. Using Progressive Ventilation- Reventilation of the mine after an explosion is usually accomplished by progressive ventilation.

Afresh air base is established and stoppings are built in parallel entries to isolate the affected area. A team wearing apparatus can then enter the affected area through an air lock (the fresh air base) to explore the mine and assess conditions.

This procedure is basically the same as unsealing a fire area by progressive ventilation.

As long as conditions are favorable, teams can enter and build a new air, lock inby the old one, build other needed stoppings in parallel entries, and prepare the area being recovered for reventilation.

Note: The teams should be sure to make the necessary adjustments to direct air from the reventilated area to a return. While exploring and preparing an area for reventilation, teams should be alert for and eliminate any possible sources of ignition.

Once the new air lock is built and gas conditions are checked, normal ventilation can be advanced to that point by taking down the old air lock and opening an airway to the return for air to circulate through the area.

Teams can continue this procedure until the entire area is reventilated.

The conditions the team encounters determines the area reventilated. When damage is slight, a team can reventilate a large area.

If damage is extensive, however, the team may only be able to do two or three blocks at a time, and much work must be done to repair ventilation controls. The reventilation process is slower where travel is hampered, or where roof and rib conditions are hazardous and require timbering and other roof support.

Once the area is reventilated, labor crews working barefaced can normally do any further rehabilitation work needed in that area. This allows the apparatus teams to prepare the next area for reventilation.

3. Dealing with Obstructed Passageways- If entries are obstructed by falls, debris, or equipment, travel through the entries may be difficult during reventilation. In these circumstances, teams should try to bypass those entries and come in behind the obstructions to erect the stoppings.

Sometimes all entries are blocked by falls. Rescue teams have, in some instances, reventilated as close as possible to the area and then used permissible machinery and tools to clear an entry.

While this is being done, line brattice can be used to ventilate the area, in the same manner that a face area would be ventilated during normal production.

Where fails are extensive, access may be gained to the obstructed area by mining through the solid from the closest unobstructed entry.

In the past in these cases, teams have mined to within a few feet of breaking through the solid. At that point an air lock was erected, the power was turned off, and all unnecessary personnel were removed from the mine.

Then a team with apparatus on went through the air lock and hand mined the last few feet.

These two procedures are mentioned to provide two examples of methods of recovery which were successfully used before. Any decision to use these methods would be made by the officials in charge of the operation who must evaluate the risks. benefits, and costs before implementing such a plan.

IV. Clearing and Rehabilitating the Affected Area

a. Roof and Rib Control- Explosions, fires, and other mine disasters frequently result in weakened roof and rib conditions. Rescue teams should carefully assess roof and rib conditions during recovery work. Teams may find extensive timbering and cribbing is needed to stabilize conditions prior to advancing ventilation.

b. Pumping Water- Rescue teams often encounter large accumulations of water during recovery operations which must be pumped out.

There are two ways to accomplish this.

1) The team is to advance fresh air to the area and then pump out the water.

2) If the team needs to clear the area before fresh air is advanced that far, and if gas conditions allow, the team can use nonconducting suction lines with a pump set up in fresh air to pump out the water.

When using this procedure, teams should make careful analysis of the gas conditions in the area being pumped. Water-soluble gases will be pumped out along with the water. If the line loses suction, toxic or explosive gases from the contaminated atmosphere can be drawn out.

Note: When advancing into an area that has been inundated with water,

teams should be very cautious of the roof and rib conditions since roof

Falls are likely to occur in these areas.

c. Clearing Roadways and Track- Roadways and track should be cleared and restored for use as quickly as possible. Once this is done, it will be much easier to bring in the materials which are needed for the recovery and clean-up effort.

d. Loading Out Falls and Hot Debris- Many times the most practical way to deal with the debris found during recovery operations is to load it onto shuttle cars or onto mine cars and haul it from the mine.

This is especially true of heated debris found after unsealing a fire area. In fact, the only practical means of eliminating the possibility of rekindling the fire is to remove the heated material.

The material should be wetted down before and during the loading operation.

When large areas of heated roof rock fall, water lances can be driven into the debris to aid in cooling it. Water lances are pipes about 10 feet long with holes cut along the length of the pipe.

The lance attaches to a regular hose line.

After the rock cools, it can be broken up and loaded out.

e. Restoring Power- Power is usually restored progressively by an electrician as the ventilation is advanced.

Once the power is restored in an area, the rehabilitation work can proceed much more efficiently since there will be power to transport materials, equipment, and workers.

f. Reestablishing the Communications System- As fresh air is advanced, the mine's communication system should be repaired or a substitute system advanced to aid in expediting the recovery operation.

Section 8

Mine Rescue Statement of Facts

Draeger BG-174 A

Mine Gases

Mine Rescue & Recovery

Firefighting & Explosions

Ventilation

I. Draeger BG-174 A

The positive pressure leak test is to insure that no oxygen escapes to the outside atmosphere during operation of the apparatus.
A leaking diaphragm will create a low opening pressure.
An old diaphragm which has lost its flexibility due to age will create a high opening pressure.
The pressure relief valve is designed to open when the pressure within the breathing circuit is between +10 and +40 millimeters (+1 mbar and +4 mbar) of pressure measured on the water gauge.
Once zero adjustment has been made on RZ-25 tester, do not readjust setting for balance of tests.
All connections must be tightened on apparatus and zero adjustment made on RZ-25 tester prior to connecting breathing hoses to apparatus.
The exhalation valve should allow the breathing air to pass in only one direction toward the regenerative canister.
During the exhalation valve test, if valve is operating properly, breathing bag should not deflate.
The inhalation valve should only allow the breathing air to pass in one direction toward the face mask.
During testing of the inhalation valve, if valve is operating properly, the breathing bag should not inflate.
During the positive pressure leak test, the needle on the RZ-25 tester should not drop more than 10 mm H2O or 1 mbar in 60 seconds.
The screw ring cover on the lung demand valve assembly and connections on the breathing bag are hand tight connections.
The negative pressure leak test is to insure that no toxic gases enter the breathing circuit during operation of the apparatus.
During the negative pressure leak test, the needle of the RZ-25 tester should not rise more than 10 mm H2O or 1 mbar in 60 seconds.
The BG-174A is equipped with a pre-flushing device which automatically purges the nitrogen rich ambient air, initially found in the breathing circuit, with pure oxygen.
Once the oxygen cylinder valve is opened and the unit is charged with oxygen, the pressure gauge on the oxygen cylinder and the chest gage on the flexible line must equalize to within 10 percent of one another.
All BG-174A oxygen cylinders that show zero pressure on the gage must be purged and vacuumed to remove any contaminant or moisture that may have entered due to lack of pressure in the cylinder.
The lung demand valve automatically goes into action if more than the allotted dosage of 1.4 - 1.7 LPM of oxygen is consumed by the wearer.
During the lung demand valve test, the valve should open between -10 mm H2O (-1 mbar) and -40 mm H2O (-4 mbar).
The breathing bag volume test is done to insure that the breathing bag has correct volume, which should be at least five liters.
Each complete stroke of the bellows on the RZ-25 tester is equal to 0.5 liter.
During the bypass test, a failure of the bypass valve to instantly provide oxygen into and fill the breathing bag at a rate of approximately 50 LPM in less than 10 seconds is an indication of an internal failure in the oxygen distributor.
Constant dosage in the BG-174A is preset at approximately 1.5 liters/minute.
Three factors affecting constant dosage are: diameter of dosage orifice, constant pressure, and elevation and atmospheric pressure.
The dosage orifice within the oxygen distributor has an opening of approximately 0.17mm.
Oxygen under a constant pressure of 57 PSI is forced through the orifice at an approximate rate of 1.5 liters/minute.
The constant pressure of 57 PSI is maintained by the reciprocating action in the oxygen distributor.
During the constant dosage test, the breathing bag is deflated, the RZ-25 tester is set to red dosage, and the pressure relief valve cover is plugged.
During the constant dosage test, the needle of the RZ-25 tester should automatically settle between 1.4 and 1.7 LPM.
Although the RZ-25 tester measures dosage, it is not a flowmeter.
The RZ-25 tester is operated by over pressurizing the breathing circuit.
The pre-flush/dosage line connection is tightened by hand.
The plug on the training canister is tightened by wrench.
When it is assured that all hand tight and wrench tight connections are securely fastened, low dosage can usually be attributed to a damaged o-ring or washer.
Any leak in the breathing circuit will prevent the apparatus from over pressurizing, thus indicating a low dosage.
The oxygen cylinder connection is tightened by hand.
The locking screw on the saliva trap is tightened by a wrench.
The hose adapter on the RZ-25 tester is tightened by hand.
The breathing hoses are tightened by hand.
During the constant dosage test, a reading of less than 1.4 LPM is low dosage.
A high dosage indication can almost always be attributed to a leak at the valve head inside the lung demand valve.
An internal leak at the valve head inside the lung demand valve may not be detectable with the positive and negative pressure leak tests.
The warning whistle is designed to activate when the pressure in the oxygen cylinder has dropped to approximately 20 percent of the original cylinder pressure.
During the whistle activation test, the warning whistle should activate at approximately 700 PSI for a four hour apparatus.
If during testing the warning whistle fails to activate at the prescribed setting, the warning whistle should be removed from the apparatus and returned to National Mine Service for adjustment.
If while wearing the apparatus the warning whistle should sound with each inhalation or with each activation of the manual bypass valve, this is another indication of clogged sieves in the oxygen distributor rather than a defective whistle.
During the whistle duration/manual cut-off test, the warning whistle should sound for 20 to 60 seconds before automatically sealing itself.
If during the whistle duration/manual cut-off test, the warning whistle sounds less than 20 seconds, it may not be giving the user an adequate warning.
If during the whistle duration/manual cut-off test, the warning whistle sounds longer than 60 seconds, it is wasting valuable oxygen.
The manual cut-off lever is located on the oxygen distributor.
The manual cut-off lever is designed to isolate the chest gage in the event the gage or the flexible line develops a leak during operation.
The valve screw should be positioned so that the chest gage and flexible line are isolated when the manual cut-off lever arm is lifted to a 30 to 45 degree angle from the horizontal.
Prior to testing whistle duration and the manual cut-off valve, turn oxygen cylinder valve off, lift the manual cut-off lever, open oxygen cylinder valve (with the RZ-25 tester set on negative pressure pumping), and start the stopwatch.
When the system is pressurized, the high pressure and medium pressure lines can be tested for leaks by coating the connections with a soap lather or leak detection solution.
The BG-174A should be stored to protect against: dust, sunlight, heat, extreme cold, excessive moisture, damaging chemicals, and mechanical damage.
All parts exposed to the circulatory system of the BG-174A must be thoroughly washed in a good detergent/disinfectant, thoroughly rinsed, and dried after each wearing.
The face mask, breathing hose assembly, breathing bag, and lung demand valve assembly are parts exposed to the circulatory system that must be thoroughly washed after each wearing.
Before washing the lung demand valve assembly, it is absolutely necessary to isolate the lung demand valve.
An improper disinfectant or one that is not diluted properly could cause the rubber or neoprene parts to deteriorate prematurely.
Alcohol is not to be used to clean or disinfect any parts of the BG-174A .
If alcohol is used to disinfect or clean, it will break down the rubber in the face mask, hoses, and breathing bag.
The temperature of the air used to dry parts should not go above 140 degrees F (60 degrees C).
Storing the rubber or neoprene parts in areas with fluorescent lighting will have the same effect as direct sunlight.
Replace the o-ring at the oxygen cylinder connection at least once every six months.
All rubber or neoprene sealing rings should be replaced at least once every two years.
A new inhalation valve should be inserted into the lung demand valve assembly at once every two years.
The lung demand diaphragm should be replaced after at least three years usage.
The o-ring under the speaking diaphragm should be replaced at least once every three years.
The o-ring under the speaking diaphragm should be replaced at least once every three years.
The oxygen cylinder must be retested by a certified testing facility every five years.
The test date in month and year is stamped on top of all oxygen cylinders.
The lung demand valve assembly should be replaced at least every six years.
The warning whistle should be returned to National Mine Service for overhaul after at least six years usage.
When copper gaskets are removed from the BG-174A for any reason, they should not be reused.
Only USP medical oxygen is to be used to fill the BG-174A oxygen cylinders.
Before filling any oxygen cylinder, check the service rating and hydrostatic test date stamped on the cylinder.
If the oxygen cylinder is rated at 2600 PSI or 2850 PSI, it can be filled up to these pressures only.
Only oxygen cylinders rated at 2850+ can be filled to 3135 PSI.
The temperature in the areas for filling and storage of oxygen cylinders should be maintained at approximately 70 degrees F.
During the filling cycle, the temperature in the oxygen cylinder will rise in proportion to how fast the cylinder is filled.
A prerequisite for the safe use of an oxygen breathing apparatus is a proper maintenance program.
It is very important that an accurate record be kept of each test performed on the BG-174A with the RZ-25 tester.
When using a factory packed regenerative canister, insure that the string or tape seal is in place and the expiration date has not been reached prior to removing the end caps and inserting the canister into the apparatus.
The expiration date is stamped on the white label attached to each factory packed regenerative canister.
The expiration date on each factory packed regenerative canister appears as a Roman numeral and year.
The BG-174A apparatus will not offer protection against poisonous gases absorbed through your skin.
The wearing harness consists of two adjustable shoulder straps with double slide buckles and a waist belt.
On the top of the oxygen cylinder is a safety device known as the pressure burst cap.
The pressure gages are marked in increments of 200 PSI and are luminous, so you can see them in the dark or in other conditions that limit visibility.
The special chemicals inside the regenerative canister absorb the carbon dioxide from the air that is exhaled by the wearer.
There are two types of canisters you can use with the Draeger BG-174A apparatus, refillable training canister and factory packed disposable canister.
The refillable training canister is made of stainless steel and can be used over and over again as long as the absorbent chemicals are freshly packed for each use.
Inside the refillable training canister is a set of baffles designed to expose more surface area of the chemicals to the exhaled air.
If the factory packed disposable rescue canister has expired, yet is still factory sealed, it can be used for training provided that the chemicals can be heard rattling around when the canister is shaken and the canister has not gained 10 or more grams in weight.
The lung demand valve assembly contains the diaphragm, pressure relief valve, lung demand valve, and inhalation and exhalation valves.
The pressure relief valve is the part of the lung demand valve assembly that keeps oxygen from building up in the breathing bag if you use less than the unit provides.
The saliva trap is on the inhalation hose because it must be located on the lowest part of the apparatus when it is worn so that the moisture will settle there.
Heat buildup within the unit's system is produced when your exhaled air flows through the regenerative canister.
The area where oxygen cylinders are filled and stored must have adequate ventilation to prevent a buildup of oxygen and reduce the potential for fire.
If you're using a high pressure oxygen pump to fill an oxygen cylinder, the pump itself should have a filter dryer installed on the gas inlet side of the pump to prevent moisture and dust from getting into the oxygen cylinder.

II. Mine Gases

Hydrogen can be liberated when water or steam comes in contact with hot carbon materials.
Hydrogen is produced by the incomplete combustion of carbon materials during fires and explosions.
Toxic gases are produced by burning rubber, neoprene, or polyvinyl chloride (PVC).
Oxygen is a supporter of combustion.
Carbon monoxide is a product of incomplete combustion of any carbon material.
Specific gravity is the weight of a gas compared to an equal volume of normal air under the same temperature and pressure.
Normal air has a specific gravity of one.
Carbon dioxide is colorless, odorless, and has a acidic taste over 10%.
Methane is lighter than air.
Carbon monoxide is explosive.
Hydrogen sulfide is highly toxic.
Nitrogen dioxide has a reddish-brown color in high concentration.
Sulfur dioxide is nonexplosive.
Nitrogen is nonexplosive.
Oxygen has no odor, color or taste.
The explosive range of methane in air is 5 to 15 volume percent.
Carbon monoxide has no color, odor, or taste.
Hydrogen sulfide has an odor similar to rotten eggs.
Nitrogen dioxide is nonexplosive.
The lower explosive limit of hydrogen is 4.0 percent.
Nitrogen has no odor, color, or taste.
Carbon dioxide is nonexplosive.
Acetylene is formed when methane is burned or heated in air having a low oxygen content.
Sulfur dioxide is highly toxic.
Nitrogen is an asphyxiant in above normal concentrations.
Continual exposure to hydrogen sulfide may dull the sense of smell.
The affinity of carbon monoxide for hemoglobin is 200 to 300 times that of oxygen.
The specific gravity of methane is 0.5545.
The specific gravity of carbon dioxide is 1.5291.
The specific gravity of carbon monoxide is 0.9672.
Carbon dioxide is the product of oxidation including the decay of timbers.
About 21 percent of normal air is oxygen.
Blackdamp is a mixture of carbon dioxide, nitrogen and air which is oxygen deficient.
Afterdamp is a mixture of carbon monoxide, carbon dioxide, methane, oxygen, nitrogen and hydrogen.
Afterdamp is usually found after a mine fire or explosion.
Hydrogen can be detected with a multi-gas detector or by chemical analysis.
In some mines, carbon dioxide is liberated from the rock strata..
To test for methane, use a methane detector or chemical analysis.
Carbon monoxide can be detected by means of carbon monoxide detectors, multi-gas detectors, or by chemical analysis.
Nitrogen dioxide is produced by burning and by the detonation of explosives.
Smoke usually contains carbon monoxide and other toxic or asphyxiating gases produced by fires.
Breathing air containing 10 percent carbon dioxide causes violent panting and can lead to death.
The first symptom of carbon monoxide poisoning is a slight tightening across the forehead and possibly a headache.
A mixture of coal dust in air reduces the explosive limit of methane.
One and one-half to two percent methane together with coal dust in air may be explosive.
Mines below the water table tend to have more methane than those above the water table.
High temperature (or heat) cause gases to expand so they diffuse more quickly.
The range of concentrations within which a gas will explode are known as its "explosive range".
Any flammable gas can explode under certain conditions.
It is much easier to remove a concentration of a light gas like methane by ventilation than it is to remove the same concentration of a heavier gas like carbon dioxide.
Only detectors and chemical analyses can positively identify a gas.
The effects of toxic gases depend on the concentration, toxicity, and exposure time.
Asphyxiants are gases which cause suffocation choking.
Firedamp is a mixture of methane in air that will burn or explode when ignited.
If there is a sufficient amount of hydrocarbons in smoke, the smoke may be explosive.

III. Mine exploration & recovery

One pull on the lifeline means that the rescue team wants to stop.
Two pulls on the lifeline means that the rescue team is going to advance, move toward the captain.
Three pulls on the lifeline means that the rescue team is going to retreat, move toward the No. 5 person (last person).
Four pulls on the lifeline means that the rescue team is in distress or emergency.
The first priority of rescue and recovery operations is team safety
The second priority of rescue and recovery operations is the rescue of survivors.
The third priority of rescue and recovery operations is the recovery of the mine.
Whenever possible, it is best to enter the mine by way of the safest intake airway.
When rescue teams travel in smoke, all team members should hold onto the lifeline or be linked together by means of a linkline.
Before opening and traveling through any stopping inby which conditions are not definitely known, you should first erect a temporary stopping outby.
The monitoring of the mine atmosphere for the presence of oxygen, methane, and carbon monoxide an important element of team exploration.
Dinner buckets encountered during exploration are important because they may contain information about the whereabouts of survivors.
Your captain must order the team to return immediately to the fresh-air base if a team member's apparatus malfunctions.
A debriefing is a session held when a team returns to the surface after completing an assignment to review what they saw and did.
In potentially explosive atmospheres, nonsparking tools, nails, and spads should be used.
When you have located a barricade, you should try to determine whether the miners inside are still alive and conscious.
Mine rescue teams may find it necessary to use line brattice to sweep noxious or explosive gases from a face area.
Explosions, fires, and other disasters frequently result in weakened roof and rib conditions.
Before a rescue team goes underground, it will attend a briefing session.
Information the team relays to the fresh air base as it proceeds is known as the "progress report".
It is the responsibility of rescue team members to have all the information needed to do the work.
When a team locates a body, its location and position should be marked on a mine map and on the roof or rib close to the body.
The rescue team captain should regulate the team's pace according to conditions encountered.
When a body is first located, every effort should be made not to disturb any possible evidence in the area.
In situations too hazardous for teams to explore and reventilate safely, teams may be instructed to seal the area.
Before the team leaves the fresh-air base to travel inby, the captain should take note of the time of departure.
It is recommended that team checks be conducted every 15 to 20 minutes.
It is recommended that the first stop for a team check be just inby the fresh-air base.
For teams using a compressed oxygen breathing apparatus, the captain usually notes each team member's gauge reading at each rest stop and reports the lowest reading to the fresh-air base.
"Tying in" is the process by which you systematically explore all crosscuts and adjacent areas as you advance.
As the team advances underground, the captain takes the lead.
It is important that the team pace its work so that it can return to the fresh-air base on time.
As the team advances, the map man records what the team encounters by marking the information on a mine map.
When reporting anything to the fresh-air base, be sure you are clearly and correctly identifying locations.LI VALUE=1>The team is responsible for choosing the exact sites within headings for building seals.
Smoke causes a lack of orientation which may cause a team member to lose his/her sense of balance.
Color, odor, and taste are physical properties that help to identify gases during barefaced exploration.
Only detectors and chemical analyses can positively identify a gas.
In order to maintain an airlock, one door of the airlock must be kept closed while the other is opened.
Rescue teams should build an airlock so that the two stoppings are erected as close together as possible yet with enough space to allow room for the team and their equipment to fit in between.
If the fresh-air base is underground, it should be located where it's assured a fresh air travelway to the surface.
The fresh-air base should be located where it's assured positive ventilation and fresh air.
Elevators should be tested before use following a disaster.
As a team advances, it is important to stay in close contact with the fresh-air base to report team progress and to receive further instructions.
In the event that rescue team communications fail, it can still communicate with the fresh-air base by tugging on the communication cable.
When using the lifeline for communication, the attendant at the fresh-air base will acknowledge receiving a signal from the team by sending it back to the team.
Team captains should inspect roof and ribs before the team members advance into the area.
Teams should not travel in water deeper than knee deep (less in low coal).
Hazardous areas should be marked to warn other teams that may enter the area after yours.
Progress reports should include reports on roof and rib conditions and gas conditions.
Coking or coke streamers, if encountered, should be reported in location and size.
The time spent underground by a rescue team is usually limited to two hours or less.
When looking for survivors, it is important to both look and listen for clues.
When survivors are located, their location, identities, and condition should be reported immediately to the command center.
When survivors are located, the location, time, and date should be marked on the team's map and on the rib where they are found.
When survivors are found, they should be transported to safety and fresh air as quickly as possible.
The main objectives of exploration work during a mine fire are locating the fire and assessing conditions in the fire area.
A self-contained breathing apparatus is a completely portable unit that supplies oxygen or air independently of the surrounding atmosphere.
A team is a unit made up of individuals working toward a common goal.
If a team member must return to the fresh-air base because of a problem, it is standard practice among teams for the entire team to go back with that person. No one should ever travel alone.

IV. Firefighting & explosions

Electrical fires are "Class C" fires.
"Class A" fires are best extinguished by cooling with water or by blanketing with certain dry chemicals.
Burning wood is an example of a Class A fire.
The recommended extinguisher for mine rescue teams is a dry chemical type that contains monoammonium phosphate.
A monoammonium phosphate extinguisher is effective in fighting Class A, B, and C fires.
Foam is useful only in fighting Class A and B fires.
Carbon monoxide is a product of incomplete combustion of any carbon material.
Opening of seals prematurely can cause a re-ignition of a fire or an explosion.
Sufficient time should be allowed for a fire area to cool before it is unsealed.
Smoke usually contains carbon monoxide and other toxic or asphyxiating gases produced by fires.
One and one-half to two percent methane together with coal dust in air may be explosive.
After a fire or explosion in a mine, rescue teams are usually needed to go into the mine to assess and re-establish ventilation.
Indirect firefighting methods allow firefighters to remain a safe distance from the fire.
Temporary seals are built before permanent seals are erected in order to seal off a fire area as quickly as possible.
In mines where head coal (roof coal) is left, a fire will spread more rapidly.
One hazard of heat during a fire is that it tends to weaken the roof, especially where head coal is left.
Small hydrogen explosions, known as hydrogen "pops" are fairly common in firefighting.
Fires can be attacked by the use of a foam generator from a distance of 500-1,500 feet.
It is generally recommended that teams not travel through foam filled areas.
One method of indirect firefighting is flooding the sealed fire area with water.
Once an explosion has occurred, there is always the possibility of further explosions.
Explosions, fires, and other disasters frequently result in weakened roof and rib conditions.
Smoke causes a lack of orientation which may cause a team member to lose his/her sense of balance.
Class B fires involve flammable or combustible liquids.
Class D fires involve combustible metals.
Before using a hand held extinguisher it must be checked for the type of fire you are fighting.
If there is a sufficient amount of hydrocarbons in smoke, the smoke may be explosive.
The most positive indicator of the origin of an explosion is the direction in which blocks have moved in or from stoppings across entries near intersections.
The roof and ribs should be tested before extinguishing a fire.
Coking or coke streamers, if encountered, should be reported in location and size.
For a Class C fire (electrical), if power has been cut off to the burning equipment, it may be treated as a Class A or B fire.
High volatile coal burns much faster than low or medium volatile coal.
Hazards of direct firefighting are electrical shock or electrocution, toxic and asphyxiating gases, oxygen deficiency, explosive gases, heat, smoke, and steam.
When fires are sealed in gassy or dusty mines, a thick coating of rock dust should be applied to the ribs, roof, and floor for several hundred feet outby the seals, and if possible, inside the seal, to reduce the chance of propagating a coal dust explosion.
Frictional water loss can occur any time the water line is less than 2 inches in diameter.

V. Ventilation

Before opening and traveling through any stopping inby which conditions are not definitely known, you should first erect a temporary stopping outby.
A smoke tube is used to show the direction and velocity of slow moving air.
When taking a reading with an anemometer, a commonly used method is to traverse the airway.
An airlock consists of two doors or two stoppings with flaps or doors in them which are in close proximity to each other in the same passageway.
The purpose of an airlock is to separate two different atmospheres while still permitting miners to enter and exit without mixing the atmospheres.
Temporary stoppings built in a crosscut should be placed at least four to six feet into the crosscut in order that sufficient space is available to construct a permanent stopping.
"Pogo sticks" are devices which may be used to erect temporary stoppings.
Temporary seals should include provisions for collecting air samples from with the sealed area.
Opening of seals prematurely can cause a re-ignition of a fire or an explosion.
Progressive ventilation is the reventilation of a sealed area in successive blocks by means of airlocks.
Direct ventilation is the reventilation of an entire sealed area at once.
After a fire or explosion in a mine, rescue teams are usually needed to go into the mine to assess and re-establish ventilation.
Temporary seals are built before permanent seals are erected in order to seal off a fire area as quickly as possible.
Mine rescue teams may find it necessary to use line brattice to sweep noxious or explosive gases from a face area.
Once ventilation has been re-established and fresh air. advanced, non-apparatus crews can take over the rehabilitation and cleanup effort.
Rescue teams are responsible for assessing damage to the ventilation system.
In situations too hazardous for teams to explore and reventilate safely, teams may be instructed to seal the area.
Regulators are used in mine ventilation to regulate air flow to meet the individual needs of each air split.
Overcasts are used to permit two air currents to cross without the intake air short circuiting to the return.
The team is responsible for choosing the exact sites within headings for building seals.
The basic principle of mine ventilation is that air always moves from high to low pressure regions.
Ventilation controls are used underground to properly distribute air to all sections of the mine.
In order to maintain an airlock, one door of the airlock must be kept closed while the other is opened.
Rescue teams should build an airlock so that the two stoppings are erected as close together as possible yet with enough space to allow room for the team and their equipment to fit in between.
If the fresh-air base is underground, it should be located where it's assured a fresh air travelway to the surface.
The fresh-air base should be located where it's assured positive ventilation and fresh air.
Urethane foam is an effective sealant when used around the perimeter of a seal.
All permanent seals should be well hitched in the floor, roof, and ribs to improve their strength.
It may be necessary to double or triple the thickness of the material in order to improve the effectiveness of the seal.
Seals should be built at locations with good roof and even roof and ribs.
gases, oxygen deficiency, explosive gases, heat, smoke, and steam.
When fires are sealed in gassy or dusty mines, a thick coating of rock dust should be applied to the ribs, roof, and floor for several hundred feet outby the seals, and if possible, inside the seal, to reduce the chance of propagating a coal dust explosion.
The formula for calculating air quantity is Q = A X V.
To calculate air quantity using a smoke tube, the formula is the length of a measured airway divided by the time it takes smoke to travel that entry.
The fan chart can determine when ventilation was disrupted or when an thermal incident occurred underground.

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