63.Liferaft launching

The life raft on board ship are released or launched in to the water by three different methods:

1)      Auto release with Hydrostatic Release Unit (HRU).

2)      Manually launching.

3)      Launching by Davits.

The Working of HRU:

• HRU acts as a connecting media between life raft container and ship deck, where it is stored.
• The HRU comes in action under the pressure of water exerted on HRU when the ship sinks below 4m of water level.
• The HRU consists of a sharp knife or chisel which is used to cut the strap lashed over the container carrying life raft, but it still holds the painter at the weak link.
• When vessel sinks, the HRU cuts the rope and the container floats to the surface of water.
• As vessel sinks further, the tension in the painter causes the life raft to inflate out of the container.
• The tension acting on the weak link will cause it to break making the life raft free from the ship.

Manual Launching Procedure of Life raft:

• Check that one end of the painter of the raft is well secured to a strong point on ship’s deck or structure.
• Remove the lashing from the container of the raft and open the way to portable rail if available.
• Check the ship side where the raft to be launched is clear.
• Two people should lift the container from both sides horizontally and throw the container.
• Make sure the painter is still fixed at a strong point so that the raft should not be waved away by waters.
• Pull the painter with a hard jerk to fire the gas bottle to inflate the raft.
• The life raft will take 20-30 sec to inflate.
• Board the life raft one by one using ladder or rope.
• Avoid sharp objects like knives, shoes and other sharp objects etc which may damage the raft surface.
• When everybody is aboard, after a headcount, cut the painter with a sharp knife.

Launching Raft by Davit:

• Open the lashing and remove the raft container from HRU by opening the manual slip hook or bottle screw arrangement.
• Tie up the one end of the painter of raft into a strong point at deck.
• Keep the container in the open and attach the davit hook to the given eye in the canister/ container
• Take up the raft load by davit and keep the container hanging at embarkation deck area.
• Pull the painter and inflate the raft. Have a thorough check on the inflated raft.
• Start boarding the raft without the shoes and other sharp object.
• After the boarding is completed, check the bottom is clear and release the securing lines, if any.