Instruction manual

PROFICIENCY IN SURVIVAL CRAFT AND RESCUE BOATS OTHER THAN
FAST RESCUE BOATS
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2) When made of cordage have the ends either whipped or heat
treated;
3) When made from a flexible wire have each end looped around a
thimble and secured with a locking ferrule.
b) Performance
A weak link shall be of sufficient strength to—
1) pull the painter out of the liferaft container;
2) operate the liferaft inflation system;
3) break under a tensile force of between 1.8 and 2.6 kN.
5.5.5 Different types of hydrostatic release unit
1. H.R.U. type “ Hammar 20”
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Fig. 5.11 Automatic release of liferaft
The Hammar 20 hydrostatic release unit is designed for liferafts from 6 to 20
persons. The unit consist of a double looped white rope line, a release
mechanism and a Red Weak Link breaking strength 2.2 ± 0.4 kN.
The strong white rope is secured to the deck or liferaft cradle and attached
to the liferaft lashing with a sliphook. If the ship sinks, the water pressure will
(within 4 metres) activate the sharp knife which cuts the white rope and the
liferaft will float free. As the ship sinks, the liferaft painter line will be stretched
and the liferaft starts to inflate. The Red Weak Link breaks and
survivors can board the floating liferaft.
The unit is made of glassfibre reinforced nylon, which means it won't rust.
The HRU H20 needs no annual service maintenance or spare parts, however it