Fire protection and fire

fighting

SOLAS (Consolidated Edition, 2009)
Międzynarodowa konwencja o bezpieczeństwie życia na morzu
Rozdział II
Konstrukcja – ochrona przeciwpożarowa, wykrywanie i gaszenie
pożarów.

Fire Safety Systems (FSS) Code, 2007 Edition
Kodeks systemów bezpieczeństwa pożarowego
Przyjęty rezolucją MSC.98(73)

Structural fire protection

Structural fire protection includes
design/construction measures such as the
subdivision into main fire sections, the arrangement
and design of doors, fire flaps and other closures,
escape- and rescue routes, the use of
noncombustible or low flame-spread materials, the
installation of fire alarm and extinguishing systems
and appliances, and of special equipment to protect
for example compartments or installations in which
combustible liquids, compressed gases or
dangerous substances are used. transported or
stored, such as fuel tanks, pumps or pipelines.

The now valid set of regulations is based on the
principle that the best fire protection for the entire
accommodation area can be achieved by using
exclusively noncombustible materials for all
bulkheads, sides and ceilings.

Structural fire protection

Class "A" divisions are steel bulkheads and decks , so
insulated with an approved material that they will certainly
prevent the penetration of smoke and flames for an hour. and
an increase in the average temperature of more than 139 °C
above the initial temperature on the side away from the fire
for a specified minimum period. This period in minutes is
appended to the type designation. A class "A-60" division for
instance meets the requirements for a period of 60 minutes.
The temperature must not at any point increase by more than
180 °C above the initial value.
Class "B" divisions are bulkheads, decks, deckheads or
claddings of approved non combustible material which will
certainly prevent the penetration of smoke and flames for half
an hour. The temperature at the side away from the fire must
not exceed 139 °C and only for shorter minimum periods than
with class "A". The maximum permissible value must not
exceed 225 °C.
Class "C" divisions must be of approved non combustible
material. For them there are no special requirements as
regards the prevention or smoke or flame penetration or as
regards insulating effect.

Structural fire protection

On all ships:

- All doors must be made of material of the same

type as the bulkheads in which they are set.
Certain doors have to be self-closing.

- All fire flaps must be made of material of the

same type as the ventilation shafts or ducts in
which they are fitted.

- The inlet and outlet apertures of all ventilation
systems must have easily accessible closure
devices on deck, which on the outbreak of a fire can
be closed manually.

Structural fire protection

The structural fire protection in the engine
room is primarily intended to prevent the
uncontrolled escape of liquid combustible
substances and, should this nevertheless occur,
prevent their being heated to their ignition
temperature. For that reason the fuel pumps and
engine room ventilation fans must have emergency
stop devices outside the engine room. Equally, the
suction lines from the fuel tanks must have quick-
closing arrangements outside the engine room. Fuel
lines are run as far away as possible from
components with hot surfaces. They must be of
such materials and so constructed as to pose a
major obstacle to the escape of fuel. Components
with hot surfaces are insulated.

Operational fire protection

Operational fire protection
in emergency bring about the rapid and secure
operation of the fire fighting appliances to prevent
spread of the fire
Structural and operational fire protection
complement one another. Both are of the same
value; they must not be separated.
Among the most important measures of operational
fire protection are:

• Safe storage of combustible working-

materials

• Protective measures for entry into dangerous

compartments

• Protective measures when welding or

working with fire

• Maintenance of firefighting installations and

appliances to ensure their readiness for use
in emergency

• Fire patrols

• Fire fighting drills - instruction ~ initial and

advanced training

Extinction mechanisms

Smothering a fire means separating the combustible
substance from the oxygen, or reducing the oxygen content of
the air until the proportion drops below the minimum necessary
for combustion. This can be done in a variety of ways, e.g. by
mixing a sufficient amount of asphyxiating gas (carbon dioxide)
with the air or by covering the substance with a layer of foam or
powder extinguishant.

Cooling means slowing down the chemical process by lowering
the temperature until the process breaks down altogether as the
temperature drops below the minimum combustion temperature.
The effectiveness of cooling depends on the heat absorption
potential of the extinguishant. Water is in this respect of
supreme importance because it absorbs, and thus extracts from
the fire, large amounts of heat energy both in being heated and
in being evaporated.

Many extinction processes use both modes together e.g. water
first acts by cooling then, once steam has been generated, also
by smothering.

Extinguishant water

Water is the extinguishant most widely available,
cheapest and easiest to use.
It is easy to transport by pumping, easy to
cany even over considerable distances through pipe
and hose lines and to convey to the location of the fire
in a solid jet or spray form over spaces necessary for
extinction.
The main way in which water extinguishes is, by
cooling. In this it is not surpassed by any other
extinguishant.

Extinguishant water

Advantages

Water can be used in many different ways, e.g. as a
solid jet, spray jet, mist, personal protective spray.
As well as the cooling effect, the solid jet has :
- impact force, by which loose burning material is torn
apart so that a larger glowing surface is exposed to
the extinguishing effect,

- penetrating effect, which forces the water deeper

into the layers of glowing material, and

- wetting properties

Water is non-poisonous and chemically neutral.

Extinguishant water

Disadvantages

At ambient temperatures below freezing point, water
can only be used to a limited extent.
Especially when used against cargo hold fires, water
can endanger the stability of the ship.
Water is absorbed by certain organic cargoes such as
grain, pulse, cellulose. This causes these to swell,
which may endanger the ship's structure.
Water can cause breakdown of electrically powered
equipment. This includes the fire pumps.

Extinguishant foam

Foam consists of :
- water to which has been added
- foaming agent, and
- air which fills the foam bubbles.

Foam as extinguishant can be mixed to different
strengths, depending on the agent and the foam tube.
A distinction is made between:
- heavy foam with frothing up to 20 times;
- medium foam with frothing up to 200 times, and

- light foam with frothing up to 1000 times.

Foaming agents are dangerous substances and must
be marked in accordance with the relevant regulations

Extinguishant foam

Heavy foam is used above all to fight liquid fires, It is
considered the only promising extinguishant for fires
in major tank farms. It is particularly suitable for
installations on the upper decks or cargo tank decks
of tankers. When used in these circumstances, its
cooling effect is also important. With appropriately
designed fixed installations, effective ranges of jet of
up to 45 m can be achieved.
Medium foam is primarily used in mobile units if large
quantities of foam are needed, as for instance for fires
in accommodation areas or cargo holds. Effective
ranges of jet are only from 2 to 10 m.
Light foam is used in seagoing shipping only
exceptionally, namely where the compartments to be
protected can be totally flooded with foam from fixed
installations.

Extinguishant foam

Foam extinguishant is lighter than most combustible
liquids. For that reason, its principal field of
application is to extinguish fires of liquids in fire class
B. For extinguishing combustible solids, foam can be
used but is not economical. In the case of fires
combining class A and B, using foam is appropriate.
Foam extinguishant covers the heart of the fire and
acts primarily by smothering. In the case of liquid
fires, that calls for an unbroken layer of foam at least
15 cm thick. The water element of the foam provides
cooling. This effect is most powerful with heavy foam
by virtue of the high proportion of water and is least
powerful with light foam.

Extinguishant powder

Extinguishant powder is produced in variety of
compositions for the variety of uses. Regularly
available on board is powder for class A,B,C fires, for
class B,C fires and in some cases for class D fires.
Extinguishant powder is kept fine-grained and runny
by means of special additives.
Dry extinguishant powder remains usable for longer
periods.
 
In dry conditions, extinguishant powder is not
corrosive. Because of its saline character
(hygroscopic properties) it must however after use be
removed from any corrosion-sensitive components.
ABC powder is suitable for use against fires in
electrical installations only if a safety-distance of
more than 3 m can be maintained it high voltages
(greater than 1000 V) can occur, as the melt formed
is electrically behaviourive.

Extinguishant Carbon dioxide (C02)

CO2 can be compressed into a liquid at 20 °C and a pressure of
56.5 bar into bottles or a pressure of 20 bar in large containers.
A sudden drop in pressure causes liquefied CO2 to cool to -78
°C and form snow ("dry ice") which reverts to gas slowly with
the absorption of heat.
Carbon dioxide has a suffocating action. This starts to take
effect as soon as a concentration of at least 10% in the air is
reached, that is only possible if it is used in enclosed
compartments.
A good extinguishing effect is above all obtained with flame-
only (fire class B, C) fires.
CO2 is used for compartment protection, e.g. in machinery
spaces, or to protect specific objects (e.g. exhaust duct, air
duct).
CO2 is suitable for fighting fires in electrical installations
as it is electrically no-behaviouring. It evaporates
completely, thus its use as extinguishant causes no damage to
electro mechanical equipment. It can however cause damage to
electronic equipment because of its low temperature of -78 °C.

Fires in ship operation

By fire prevention measures, the preconditions for a
fire breaking out are eliminated as far as possible,
and any fire which does break out in spite of all the
precautions remains restricted to its originating area.
It is then a matter of a small fire or, if the fire spreads
to several spaces in an area, of a medium fire.
The equipment of the ship with fire fighting
installations and appliances and the training
and repeated drilling of the crew in fire
fighting makes it possible to fight such fires
immediately and effectively.
Experience teaches that a fire on board which
spreads beyond its originating area to become a
large fire can no longer be extinguished with the
means available on board. That increases the
importance in fire fighting of rapid, resolute and
drastic action.

Fires in accommodation spaces

Special characteristics:
The accommodation area is subdivided into a
multitude of small spaces. The initial fire is in most
cases small. The escape routes may become
obscured by dense smoke which develops, People are
in immediate danger.
Fire protection:
The fire is restricted to its original seat by the use of
non combustible materials. Fire alarms make early
discovery of an outbreak of fire possible.
Fire fighting:
By bringing the entire accommodation area to the
closed-down state, the fire is restricted to area
where it started and is extinguished by the crew
using fire protection and fire fighting equipment.

Fires in the cargo area on dry-cargo vessels

Special characteristics:
Because of the large size of the spaces, with little
subdivision, restriction to the original seat is not
always possible. If the cargo hold transverse
bulkheads are not constructed as fire boundaries,
spread of the fire to adjoining compartments cannot
be ruled out.
Fire protection;
Fixed fire alarms permit early recognition of an
outbreak of fire. Closures for loading hatches,
accesses, ventilation inlets and outlets permit
prevention of the ingress of atmospheric oxygen.

Fires in the cargo area on dry-cargo vessels

Fire fighting:
By bringing the area of the fire and the adjoining
spaces to the closed-down state, the ingress of air
and the oxygen it contains is prevented. Fixed fire
fighting installations allow the fire to be restricted to
the cargo hold in which it broke out, and extinction
by smothering.
The employment of fire fighting units often does not
make sense or is not possible, as the seat of the fire
is not accessible and opening-up the compartment
would allow free access to combustion air - which
would increase the danger of the fire growing into a
large one. Spread of the fire is made more difficult or
prevented by water-cooling the closures, transverse
bulkheads and decks.

Fires in the cargo area of container vessels

Special characteristics:
On the condition that only approved, undamaged
containers suitable for the cargo in question are
used, experience indicates that the danger of a fire
spreading within the cargo area is small. No case is
known of a fire in a sealed container not going out by
itself due to lack of oxygen, far less of one spreading
to adjoining containers.
Fire protection:
Sealed containers have such good properties in the
context of fire fighting that special additional
measures are not necessary.
Fire fighting:
if the suspicion arises that a fire might have broken
out in a container, because for instance the paint on
it discolours , spread of the suspected fire to
adjoining containers or areas is prevented by cooling
with a lot of water.

Fires in the deck cargo

Special characteristics:
The seat of the fire is usually accessible. Oxygen for
combustion is available in unlimited quantities.
Fire protection:
No special protective measures, but care should be
taken to see that fixed fire fighting installations
(deck-washing- and fire main with hydrants) are
accessible and in emergency can be used for fire
fighting.
Fire fighting:
On ships under way, provided the navigational
circumstances permit, course and speed are chosen
primarily to lower the air speed at the seat of the fire
as far as possible, and if possible to avoid causing
people on board discomfort from smoke. A fire
boundary is created by means of a „water wall". If
necessary, endangered cargo is removed from the
danger zone.

Engine room fires

Special characteristics:
Because of the large quantities of fuel present in
engine rooms there is a risk that if a fire breaks out it
will very quickly spread over the whole area. Due to
the height of the engine room, a thermal lift develops
above the fire which promotes its growth unless the
engine room ventilation is shut down and the fire
flaps are closed.
As a result of distant effects, engine room fires can
also produce failures of operationally important
systems away from the engine room. That can lead
to persons being endangered even at some distance
from the seat of the fire.

Engine room fires

Fire protection:
Apart from the machinery control room, there are in
general no permanent fire boundaries within the
machinery area. Special regulations regarding
structural fire protection apply to fuel-transporting
systems. There is a fixed fire fighting installation. In
part-time unmanned engine rooms there are fixed
fire alarm systems.
Fire fighting:
Every fire in the machinery area brings with it the
risk of expansion into a large fire. It is therefore
essential to order immediate closing-down of the
area and interruption of the fuel supply, provided the
navigational situation permits this. To fight the fire,
primarily the fixed fire fighting installations are used.

Fires as the consequence of

explosions

Explosions can occur if dangerous goods of
class 1 are heated above their ignition
temperature due to an accident such as a
collision, or if vapour-air mixtures form in
empty, inadequately ventilated or not inerted
tanks and are ignited.
An explosion will destroy the area boundaries partially
or entirely; at the same time, installations or
appliances will be rendered unusable for fire fighting.
Persons may be killed or injured. There may be
flooding and the risk of sinking.
Because of the immediate crossing of the region
boundaries, a fire following an explosion becomes a
large fire.
In many cases it will be necessary to prepare to
abandon the ship at the same time as attempting to
create a new fire boundary.

Fires as the consequence of

explosions

Because of the immediate crossing of the region
boundaries, a fire following an explosion becomes a
large fire.
In many cases it will be necessary to prepare to
abandon the ship at the same time as attempting to
create a new fire boundary.
Fire fighting:
If the navigational situation permits, course and speed
are chosen to reduce air movement at the seat of fire
and discomfort or danger to those on board from
smoke as far as possible. At the same time all
available means are employed in an effort to restrict
the fire.
A call for help cannot be avoided in such situations
and is made without delay.