Instruction manual

PROFICIENCY IN SURVIVAL CRAFT AND RESCUE BOATS OTHER THAN
FAST RESCUE BOATS
6 9
Fig. 6.10 The description of the automatic release hook Mk 5 from RFD
When the lanyard is pulled, the pawl travels along the slot through which is
the pawl pin, allowing it to move away from the return spring when the lanyard is
pulled, and to return when released. As the pawl moves so steps on the pawl and
latch, which are in engagement, rotate the latch. This also moves the lower step
on the latch out of engagement with that on the hook. The two large springs act
to open the hook as its load is reduced. In case of non-opening, the lanyard must
be pulled again, the second position latch rotating the latch still further and
contacting part of the hook. This applies an opening force capable of releasing a
load of up to 100 kg. on the fall.
Off load (normal) release
With the hook in the safe position, the hook cannot open. When the boat is
approximately 2m. above the water, pull the lanyard. The weight of the boat will
hold the hook closed. As the weight comes off the hook, it will open
automatically.
Partial load (emergency) release
Should the hook fail to open, pull the lanyard strongly again. In this case
the pawl engages in the second position on the latch, rotating it further when it
applies an opening force on the upper part of the hook, which is capable of being
forced open when the load on it is less than 100 kg.