Lifeboat davits are mechanical launching systems used to lower lifeboats safely from their stowed positions into the water during emergencies. They are designed to ensure that survival craft can be launched quickly, safely, and efficiently under various operating conditions.
Most lifeboats are launched either by gravity davits or hydraulic gravity davits. In both systems, the actual lowering of the lifeboat is normally carried out using gravity, ensuring dependable operation even during power failures.
Several types of davits are commonly used onboard ships, including:
- Pivoting (Luffing) Davits
- Trackway Davits
- Telescopic Overhead Davits
Gravity davits rely primarily on the weight of the lifeboat to swing it outward and lower it into the water. Hydraulic gravity davits use self-contained hydraulic power packs to move the lifeboat from its stowed position to the launching position before gravity takes over during lowering.
For gravity davits, the lifeboat is swung out simply by releasing or lifting the brake handle. In hydraulic systems, hydraulic power first swings the boat outward before the brake handle controls the lowering operation. In both systems, the brake handle incorporates a dead-man feature that immediately stops the descent whenever the operator releases it.
The lowering speed of the lifeboat is carefully controlled by a centrifugal brake, ensuring a smooth and safe descent regardless of the weight of the boat.
Both types of davits use wire gripes to support the weight of the lifeboat while it remains in its stowed position. These gripes prevent the boat falls from remaining continuously under tension and also secure the lifeboat against accidental movement while the ship is underway.
Additional safety features include harbour pins, which prevent the davit arms from being operated while the ship is in port or during maintenance. These pins also reduce the risk of accidental boat release while servicing the falls or release hooks. Safety maintenance pins further prevent accidental opening of the release hooks.
Overhead gravity davits are specifically designed to provide a completely unobstructed deck area beneath the lifeboat, improving deck operations and accessibility.
For lifeboats that are first lowered to the embarkation deck before boarding, tricing pendants and bowsing-in tackles are used to hold the boat close alongside the ship. These devices make boarding safer and prevent the loaded lifeboat from swinging excessively away from the ship’s side during launching.
The safe operation of davits depends heavily on proper crew training. Regular launching drills conducted under appropriate supervision help ensure that personnel remain familiar with the equipment and emergency procedures.
