On-Load Release Gear System(E)

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Survey Guidel ine On- Load Release Gear System

(2009) 1

May, 2009

Survey T eam


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1. General

T her e are many cases th at th e cr ew on board are not f amil i ar wi th th e

operational detail s of the release gear system and its check items as the

crew would be changed frequently . T he t horough ex aminat ions for t he

release gear system are conducted mostly by the service engi neer. A s the

lack of understanding on the li feboat launching system, especiall y on the

on- l oad r el ease gear syst em h as caused ser i ous acci dent s, even

l i fe- threateni ng one, the stri ct and correct i nspection, and the educati on f or

the crew on board are vital for the prevention of the accidents, for which

the surveyors are requi red to conduct the survey based on the k nowl edge of

the system.T he gui del i nes descr i be th e oper ati onal detai l s of th e rel ease gear syst em

and i tems to be carefull y exami ned duri ng the peri odi cal survey.

2. P rocedure for releasing the l i feboat

T he mechani sms f or rel easi ng th e l i f eboat betw een on- l oad and of f - l oad

condi tions are di ff erent of which each procedure i s as the foll owi ng fi gures;


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3. On- load rel ease gear system

Every li feboat to be launched by a f all or fall s, except a free- fall li feboat,

sh al l be f i t t ed w i th a r el ease mech ani sm compl y i ng w i t h t he f ol l ow i ng

requirements:

1) A ll hooks are to be released simul taneously.

2) T he mechanism shal l have normal (off- l oad) and on- load release

capabi l i ti es. Rel ease system shal l be so arranged as to rel ease the

l i feboat under any condi tions of l oading from no l oad with the l i feboat

waterborne to the l oad of 1.1 ti mes the total mass of the l if eboat when

l oaded wi th i ts full complement of persons and equi pment.

3) T he release control shall be clearl y mark ed wi th a colour that contrasts

wi th i ts surroundi ngs.

4) T he fi xed structural connections of the release mechanism in the boat

shall be designed with the calculated safety factor of 6 based on the

ul ti mate strength of the material used.

5) Every li feboat shall be fi tted wi th a device to secure a painter near its

bow. E x cept for free- fall l i feboat s, t he paint er securing device shall

i ncl ude a r elease device to ensure the painter to be released from i nside

the li feboat, with the ship maki ng headway at speeds up to 5 knots in

calm water.


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4. On- load rel ease gear

O n- load release gear syst em consis ts of fore and aft hooks , a release

handle near the steeri ng console, a hydrostatic unit and the associated

cables as the following figure;

5. Fore and aft hook units

5.1 Structure and parts names

T he structure and parts names of th e f or e and aft hook s are as th e

following figure;


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5.2 Releasing

When t he release handle near t he st eering console is pull ed, t he cam

lever pin is turned by the control cable and the lock piece i s then made

free. Fi nal l y the hook is to be turned and released.

5.3 ResettingA fter the resetting of hooks, the posture of each hook is held by the l ock

pi ece and t he l o ck pi e ce i s l o ck ed by t he cam l e ver pi n w i t h t he r eset

l e ver . T o ensur e t he pr oper r eset ti n g of t he f or e and af t h ook s, t he

foll owing procedures should be conformed. T he fore and aft reset levers

must be operated simultaneously. Af ter simultaneous resetting of the

hooks, the release handl e near the steeri ng consol e al so i s to be returned

to the closed position.


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T he hook and cam(f ace- to- f ace) are to be cor rect l y reset .


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6. Release handle unit

6.1 Structure and parts names

T he structure and parts names of th e rel ease handl e are as th e f ol l owi ngfigure;

6.2 Operation

When the li feboat is full y waterborne, the li feboat could be released by

removing t he safet y pin and t hen pull ing t he release handle full y and

qui ckl y to the open positi on(off- l oad release). T he l i feboat could al so be

released by the same operation of the release handle even though the

li feboat is not full y waterborne, by openi ng the i nterl ock cover and l i fti ng

up t he i n ter l ock l e ver . T h i s over - r i des t he i n ter l ock f unct i on of t he

hydrostati c uni t (on- l oad rel ease).


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7. H ydrostati c i nterl ock unit

7.1 Structure and parts name

Structure and parts names of the hydrostatic interlock unit are as the

following figure;


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7.2 Operation

Wh en t he l i f e boat i s f ul l y w at er bor ne, t he h ydr ost at i c i n ter l ock uni t

pushes up the interl ock lever through the interl ock cable by the water

li ft ing t he float and t hus all owing t he release handle t o be operat ed.Contrary t o t his, operat ion of t he release handle is not all owed by t he

hydrostatic interlock unit when the l if eboat i s not full y waterborne.


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8. Items to be examined

1) Correct operati on and mai ntenance condi ti on for on- load rel ease gear

a) Smooth operati on of the rel ease handl e, h ook and cam (N o sei zing)2) C orrect r eset of the hook

a) Gap between the hook tai l and cam to be withi n the manufacturer's

l i mi t (to be measured duri ng hook rel eased)

3) Spri ng conditi on of the i nterl ock lever

4) C orrect reset of the i nterl ock arr angement

a) Overl apped area of release handle by the interlock l ever to be withi n

the manufacturer's requirements

5) H ook unit condi tion (e.g. side brackets)

6) H ook supporti ng brack et condi ti on

7) Operati ng cabl e condi ti on

a) Cable condition throughout the lifeboat

b) Cabl e clamp and nearby condi ti on (l oose, mi ssi ng or corrosion)

c) Cabl e connecting condi ti on

8) H ydrostati c i nterl ock unit condi tion

a) Diaphragm conditionb) Connecting condi tion between the piston plate and i nterl ock cabl e

9) Display of the l if eboat l aunching procedure i n the boat

9. Main inspection items

2)H ook r eset posi ti on 2)H ook gap 3)I nter l ock spr i ng condi ti on


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4) I ncor r ect i nt er l ock 4) Over l apped ar ea 5) Cor r oded h ook si de B k t

setting

6)H ook suppor ti ng B k t 7)Di stor ti on 7)C abl e cor rosi on, damage

7)D amaged cabl e 7) Cor rosi on near by 7)D etach ed i nt er l ock cabl e

cable clamp

8)Conditi on of the hydrostatic i nterl ock unit and the cable connection

On-Load Release Gear System(E)

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