This required that all of the original, or Mark 1*, ‘on-load’ release hooks that had been installed to be subjected to a mandatory evaluation by the manufacturer. The aforementioned investigative process resulted in what might be described as an IMO ‘recall and upgrade’ as stipulated by MSC.1/Circ.1392. As the lever is operated from inside, it is safe to free the boat without going out of the lifeboat, when there is a fire on the ship. A lever is provided inside the boat to operate this mechanism. 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. The load will be still in the fall as the boat would not have touched the water. The provision of these capabilities required complex engineering to accomplish with up to 88 different designs being tested and ultimately approved by the IMO. The ‘on-load’ hook was designed to allow the lifeboat crew to release both davit hooks simultaneously before the boat was fully waterborne in either calm or heavy seas and even if the launching vessel had not come to a full stop. The high incidence of ‘off-load’ hook accidents motivated the creation of the ‘on-load’ release hook and the phasing in of its SOLAS mandated utilization. Such placid conditions rarely exist when abandoning ship and this resulted in numerous accidents and fatalities while attempting to disconnect the ‘off-load’ hooks. 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. The piston will continue to move up, pushing the lever and as a result, it will operate the hook arrangement releasing the fall wire. 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. There is a hydrostatic piston unit provided at the bottom. It was simple and worked well if a lifeboat was launched in more or less perfect conditions i.e. It was intended to permit manual release only when the lifeboat was fully waterborne and all weight was off the davit block hooks. The original ‘off-load’ hook is of 19th century design. By releasing the hook, the lifeboat can be set free to propel away from the ship. These mechanisms release the boat from the davit, which is attached to a wire or fall by means of a hook. There are two types of lifeboat releasing mechanisms “on-load” and “off-load”. In this article, we will take a look at the main types of “lifeboat releasing mechanisms”. Not all the lifeboats have the same type of releasing mechanisms, for the launching of a lifeboat depends on several other factors. There are different types of lifeboats used on board a ship on the basis of the type of ship and other special requirements.
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