Lifeboat Winch – Gravity Davits
Electric or Pneumatic drives is used for lifeboat winch
Electric & Pneumatic drives – Safety Features
- When lowering no mechanical assistance except gravity (i.e. only the weight of the boat) shall be applied
- The only physical work needed being release of winch hand brake (dead man’s handle – a weight is attached to the brake handle) during the lowering operation
- centrifugal brake provides controlled speed (36m/minute) to the lowering when hand brake is released
- If the operator looses balance and fall off, the hand brake gets engaged due to the weight in the handle (dead man’s handle) & the lifeboat shall remain stationary at the place of stop.
- A ratchet mechanism in the hoisting arrangement ensures that the drum will not reverse and the boat fall back into the water to provide safety in the event of power failure while lifting.
- Manual Hosting and Power Hoisting cannot be done at the same time (interlock is provided between positioning of manual hoisting lever & positioning of power hoisting lever)
Both the centrifugal brake and the hand brake remains stationary during hoisting operation. If the power fails while hoisting the boat, hand brake will hold the boat
- Davits should have a positive turning out moment during the whole of the davit travel with the vessel listed at any angle up to and including 250
- Davits should have enough strength so that lifeboat can be safely lowered to the water from the embarkation deck with its full complement of persons on board when the ship has a trim of up to 100 and is listed up to 150 either way
- Davits should be fitted with “tricing pendants” to bring the boat alongside the embarkation deck, unless boat is designed to be boarded and launched directly from the stowed position (free fall fully enclosed lifeboats)
- Falls should be released only when the lifeboat is waterborne
- Limit switches should be provided to stop the hoisting motor when boat has reached the stacking position
One Reply to “Lifeboat Winch – Gravity Davits(Electric or Pneumatic drives is used for lifeboat winch)”
This is truly helpful, thanks.