SAF21 SINGLE ARM SLEWING

RESCUEBOAT/LIFERAFT DAVIT

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（215ZF228-00P₆SM）

说 明 书

INSTRUCTION

镇 江 船 舶 辅 机 厂

ZHENJIANG MARINE AUXILIARY MACHINERY WORKS

中 华 人 民 共 和 国

THE PEOPLE'S REPUBLIC OF CHINA

1. General

This single arm slewing lifeboat davit conforms to the requirements of MSC.47(66)-Amendments to SOLAS 1974 and MSC.48(66)-Rules for Lifesaving Appliance.

The slewing davit is mainly used for lifting and lowering a boat. It have the functions of electrical(manual) hoisting, gravity lowering, hydraulic slewing (Oils fed from the pump station or accumulator). It is provided with lowering and slewing functions operated from deck or remotely controlled from a position within the boat. According to the arrangement of ship, the davit is of two types, right and left. Either of them is selected as per customers' demands.

2. Main parameters

1. Max. safety working load 21 kN

2. Max. slewing and hoisting load 18 .5kN

3. Max. hoisting height 25 m

4. Hoisting speed of raft ＞18 m/min

5. Lowering speed of boat 40～55 m/min

6. Size of wire rope 18×19, φ16,

Min. breaking load 130 kN , Galv.

7. Slewing radius 4 .0m

8. Slewing angle < 330⁰ (Oils fed from pump station)

≥130⁰ (Oils fed from accumulator)

1. Pressure of nitrogen of accumulator > 9 Mpa

2. Electric slewing speed abt. 0.25 r/min

3. Construction and working principle

This davit mainly consists of jib, slewing tray, hydraulic slewing device, hoisting mechanism, accumulator, slewing bearings, limit device, remote control device and head blocks as well as lifting mechanism etc.

The lifting jib is a mainly holding structure of the davit. It can accomplish turning the boat and sundries from inboard to outboard position depending on the outrigged jib.

The slewing tray is a assembly connecting jib and slewing bearings. It can effectively slew the jib to outboard position or to stowed position through the hydraulic slewing device.

The hoisting mechanism is a main assembly for recovering and launching boat. It controls lowering and hoisting of wire rope of hoisting mechanism through head block so as to achieve the aim of recovering and launching boat.

The limit device is a security device for avoiding the raft(sundries) overhoisting.

The remote control unit is used for effectively controlling the turning position and lowering height of raft through the remote control wires operated from a position within the raft in case that all passengers have embarked boat and there is no any operator on the deck.

Lifting mechanism is main equipment for hoisting and lowering sundries.

3. Mounting and adjusting (For hydraulic parts, see attached drawing)

1. Mount main davit assembly as per final documents supplied. Put the power cable into the foundation, then pass it through slewing tray, slewing bearing and then to the cable hole under the electric control box . (power cable may be led out nearby the control box by shipyard.), final switch on power.

2. Limit blocks of slewing limit device is positioned by shipyard based

on the position needed by actual slewing operation.

3. Mechanical oil N68(Equivalent ISO VG68) adopted for lubricating the

reduction gear of hoisting mechanism with oil capacity of 30 liter. Hydraulic oil YB-N46 is filled into the oil box of pump station with oil capacity of 40 liter. Under ambient temperature of minus 30 degree, synal oil No. 4403 will be adopted in the reduction gear box of the hoisting mechanism with oil capacity of 30 liter. And the oil tank of pump station should adopt hydraulic oil YC-N46D with oil capacity of 40 liter.

4. Upon the completion of mounting. First jog inching the hoisting button to observe whether the drum of hoisting mechanism is turned correctly. If the drum doesn't rotate, change the wiring of power source till correct.

5. After taking the manual handle out, the el.motor of hoisting mechanism

shall be unable to start under the action of interlocking switch.

6. Electrical slewing

Close shut valve (Pos. 1 and 2, See attached drawing A), and operate the remote control button box to accomplish turning right and left.

6. Slewing driven by accumulator

Open shut valve(Pos. 1) and operate manual slewing triangle ring to

accomplish slewing . (Driving of accumulator is one-way).

8. Charging of accumulator

Open shut valve(Pos. 1) and start pump station . Till running is in order, start the air charging button to charge till 19 Mpa, at this time shut off shut valve(No.1) and stop pump station.

5. Commission and attentions

1. Lowering boat (with power)

Release all wire ropes fixing boat.the operator switch on power of el. Control box and start push button of pump station . Open button box to tale the remote control button out and press the hoisting button to ensure the drum for hoisting mechanism winding in wire rope. The hoisting button may be depressed till the boat leaves deck and there is no any barriers effecting slewing. Then press the button for turning left(or right) , the raft may turn to outboard position, and the passenger embark raft. Upon the completion of embarking, the operator pull remote control lowering manual handle to ensure the brake of hoisting mechanism release, the raft will lower to water surface depending on its own weight .The automatic release hook will open, the raft will leave parent ship.

1. Recovering boat

Operator on deck raise winch counterweight to lower the release hook . The release hook will lower till the person on the boat engage on the hook, at this time, the operator switch on hoisting button(at this time, the weight of boat not exceed 18.5 kN) till the boat is hoisted above the deck. (Hoisting limit may be accomplished by adjusting the limit block under the hoisting limit device). Then, by pressing the button for turning right(or left) , the boat will be turned in to stowed position and stopped.(It may be also controlled by slewing limits), next the operator on the boat pull the manual remote control handle (or the operator on deck raises counterweight)to slowly lower boat till on the deck. After the passenger disembarks boat, the boat is fixed at its stowed position.

2. Launching boat (In case of failure of power)

After releasing all wire ropes which fix the boat and opening shut valve(Pos. 1), the passengers take the manual handle out and inserts it into manual hole to turn in anti-clockwise direction to ensure the boat hoisted to where there is no barriers effecting slewing. At this time, the person on the boat pull the slewing triangle ring to ensure the boat turned out, then the passenger embark the boat . Upon the completion of embarking, the operator pull lowering remote control handle, the boat will lower to water surface depending on its own weight. The boat may leave parent ship by the release hook .

IV Attentions

1. Periodically check the oil charging pressure of accumulator not less then once every month, it shall be kept from 18 to 19 Mpa, if below 18 Mpa, it must be filled with oil.

2. Periodically check the nitrogen charging pressure of accumulator not less than once every month. The charging pressure shall be kept from 8 to 9 Mpa. If below 8 Mpa, it must be charged with nitrogen.

3. The shut valve (Pos.2) is usually under closing condition. Only when repairing accumulator, the shut valves (Pos. 1 and 2) will open at the same time.

4. Hydraulic oil in the pump station shall change annually. Filter core shall be periodically cleaned once every three months.

5. Lubricating oil in the hoisting mechanism shall be changed annually.

6. Often fill lubricating grease (ZG-3) in every grease nipple and boat falls.

1. Dismantle and clean clutch , and check friction lining after the hoisting mechanism is put into use for six(6) months. The disc friction lining shall be replaced if the thickness of ferrous-base powder metallurgy and quenched steel is less than 0.5 mm. The friction lining of speed-limiting device shall be replaced if the thickness of ferrous-base powder metallurgy and quenched steel is less than 0.5 mm.

7. On consider of the safety of person, the electric motor is prohibited to start while manual operating so as to avoid accidents caused by mis-operation. Switch off power of electric control box before manual operating.

8. When the counterweight is below horizontal plane and downward, it means that the friction lining of clutch has been worn. At this time, it is only needed to loose fixed screws and make a mark on the internal & external gear ring, pull the rod out and adjust one to two teeth upward , then insert it and screw down lower screws, this friction lining may be continued to use.

9. Wire rope shall be replaced while the boat falls is broken more than 10% of the diameter of wire rope or the wire rope is twisted.

Cautions

It's prohibited to raise counter-weight and start hoisting button while manual operating.

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