Many survival craft are launched using wire rope falls and powered winches. These systems must be designed to provide safe, smooth, and reliable launching and recovery under all operating conditions.
The launching mechanism must be capable of being operated by a single person from a designated position on the ship’s deck. During launching, the operator should always be able to maintain a clear visual view of the survival craft or rescue boat.
The falls used for lowering lifeboats must be manufactured from rotation-resistant and corrosion-resistant steel wire rope to ensure long service life and reliable performance in the harsh marine environment.
Where multiple-drum winches are installed, the wire ropes must wind off and wind onto each drum at identical speeds during lowering and recovery. This prevents uneven loading and ensures the survival craft remains level throughout the operation.
The braking system of the launching appliance must be strong enough to withstand rigorous testing. It should successfully pass:
- A static load test using a proof load of at least 1.5 times the maximum working load.
- A dynamic load test using a proof load of at least 1.1 times the maximum working load while operating at maximum lowering speed.
Each launching appliance must also include an efficient manual recovery system. The handles or wheels used for manual operation must remain stationary while the winch is operating under power or while the survival craft is being lowered.
Every launching appliance must be fitted with a reliable braking system capable of stopping the descent of the survival craft at any point and securely holding it while fully loaded with all approved persons and equipment. Brake pads should be protected against contamination by water and oil to maintain consistent braking performance.
Manual brake systems must be designed using the fail-safe principle, meaning the brakes remain automatically applied unless the operator deliberately holds the brake control in the OFF position from either the deck or inside the survival craft.