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Launching Survival Craft [Video Lesson]

Once the Abandon ship order is given, the crew will muster at the lifeboat station and lower the lifeboat. If the ship is listed or due to unavoidable circumstances lifeboat lowering is not possible then a life raft is used as the survival craft.

 

Launching of Lifeboat:

  • A minimum of five individuals is necessary to decrease the L/B ratio.
  • To initiate the process, one person should enter the L/B area and secure the end of the toggle painter, subsequently plugging the drain. It is essential to inspect all lifelines and falls to ensure that they are clear of the L/B.
  • Next, secure the other end of the toggle painter onto a sturdy point forward of the vessel. Remove both the forward and aft gripes and have both individuals standing by to pass the bowing tackle and tracings pendant. Then, remove the harbour safety pin, and confirm that the ship’s side is devoid of any obstacles, including water and garbage.
  • At this point, one person should slowly lift the dead man’s handle, which will release the brake. The boat, along with the cradle, will descend until it reaches the embarkation deck. Using the tracings pendant, bring the boat alongside the embarkation deck, and allow individuals to embark inside.
  • Once everyone is aboard, remove the tracings pendant, and transfer the entire load onto the falls. Subsequently, continue to lower the boat using the dead man’s handle.
  • The release of the lifeboat to make it free from the falls will depend on the releases system which can be of onload or offload type

 

On load mechanism:

On load mechanism can release the lifeboat from the wire, with the ship above the water level and with all the crew members inside the boat.

 

The load will be still in the fall as the boat would not have touched the water. Normally the on-load release is operated when the boat is about to touch the surface of the water so that the fall is smooth without damaging the boat and harming the crew inside.

 

A lever is provided inside the boat to operate this mechanism. As the lever is operated from the inside, it is safe to free the boat without going out of the lifeboat, when there is a fire on the ship.

 

Offload mechanism:

The offloading mechanism releases the boat after the load of the boat is transferred to water or the boat has been lowered fully into the sea.

 

There is a hydrostatic piston unit provided at the bottom. the piston is connected to the operating lever via a link. As the ship becomes waterborne, the water pressure will move the hydrostatic piston up.

 

The piston will continue to move up, pushing the lever and as a result,  it will operate the hook arrangement releasing the fall wire.

 

There is a safety pin arrangement provided near the clutch box, which disables the offload release (in case of rough weather or hydrostatic piston malfunction) allowing the operator to perform on-load release of the lifeboat.

 

Video Lesson:

 

Launching of liferaft

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

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

2)      Manually launching.

3)      Launching by Davits.

 

Auto Release with Hydrostatic Release Unit (HRU):

The life raft HRU plays an important role when it comes to saving a life during an abandon ship situation. SOLAS 74 clearly specify the requirements for the construction and positioning of the HRU at the life raft.

 

The Working of HRU:

  • HRU acts as a connecting media between the life raft container and the ship deck, where it is stored.
  • The HRU comes into action under the pressure of water exerted on the 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 the life raft, but it still holds the painter at the weak link.
  • The HRU is connected to the container through a lashing arrangement which can be disengaged quickly by means of a slip hook when launching the raft manually.
  • The HRU is connected to a strong point on the deck through a weak link.
  • When the vessel sinks, the HRU cuts the rope and the container floats to the surface of the water.
  • As the 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.
  • When the vessel sinks, the HRU cuts the rope and the container floats to the surface of the water.

 

Manual Launching Procedure of Life Raft:

  • Check that one end of the painter of the raft is well secured to a strong point on the ship’s deck or structure.
  • Remove the lashing from the container of the raft and open the way to a portable rail if available.
  • Check the ship side where the raft is 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 water.
  • 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 a 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 one end of the painter of the raft into a strong point at the 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 the 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 another sharp object.
  • After the boarding is completed, check the bottom is clear and release the securing lines, if any.
  • Someone inside the raft will detach the hook of the davit from the raft when the raft is just above the water.
  • The davit operating person will board the raft either by jumping into the sea, raft or by other boarding means if provided.
  • Cut the painter and cast away the raft from the ship.

 

Video Lesson:

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