Lifeboat Davit

What sets a lifeboat davit apart

A davit does not carry people on and off the ship in normal operation the way a gangway or pilot ladder does — it exists for the one scenario those do not cover: launching and recovering a lifeboat under gravity or power, including in circumstances where the ship has lost power or has a list. Where accommodation ladders are rigged and struck routinely in port, a davit is designed to work reliably after months of inactivity and, for the launch itself, to release a fully loaded boat safely even if the ship is listing up to the angle SOLAS requires it to still function at.

Main components

Davit arm and winch

Gravity davits swing the boat out under its own weight once the trigger releases the gripes, then lower it on a wire controlled by a centrifugal or electromagnetic brake in the winch, without engine power. Luffing davits and davits for freefall boats use different geometry but share the same core requirement: controlled, brake-limited lowering.

Hook and release gear

The on-load release gear lets the boat be released from the falls with people aboard once waterborne, and separately, an off-load release for recovery. This mechanism is the single most safety-critical part of the whole davit, since accidental release during lowering has caused fatal accidents across the industry.

Wire falls and brake

Falls are wound onto the winch drum and periodically end-for-ended or renewed based on wear and service life, since they are the only thing holding a loaded boat during lowering. The winch brake must hold the boat stationary at any point in the descent, not just stop it at the bottom.

Limit switches and gripes

Limit switches stop the winch at the stowed and fully lowered positions, and gripes secure the boat against the ship's motion while stowed, released automatically or manually as the first step of launching.

Selection and sizing

• Safe working load matched to the fully equipped and manned lifeboat weight, with the required safety margin above that figure
• Outreach sufficient to clear the ship's side at the maximum design list and trim angle
• Lowering speed within the range that keeps the boat under control without exposing occupants to excessive rate of descent
• Compatibility of the on-load release gear with the specific hook type fitted to the lifeboat, since these are not universally interchangeable across makers

Regulations and class

SOLAS Chapter III and the LSA Code set the requirements: davits must launch a fully loaded boat with the ship listed up to 20 degrees and trimmed, at specified lowering speeds, and on-load release gear must meet the design and testing requirements introduced after a series of fatal accidents traced to accidental release. Falls have a defined maximum service life, commonly five years, after which they must be renewed regardless of apparent condition, and the full launching arrangement is load tested at intervals set by class, typically at each five-year renewal survey alongside the annual and periodic operational tests required by the LSA Code.

Typical faults

• On-load release gear hook wear beyond limits — increases risk of accidental release and is a leading cause of lifeboat launching fatalities industry-wide
• Winch brake linings glazed or contaminated with grease — boat descends faster than the rated speed or fails to hold position part-way down
• Falls corroded internally while looking sound externally — wire rope failure during lowering with no visible warning beforehand
• Limit switches misaligned after maintenance — winch does not stop at the stowed position, straining the davit structure on the next hoist

What to look for in a supplier

• Type approval certificate for the specific davit and release gear combination, not the davit alone
• Documented compatibility with the exact lifeboat hook fitted, confirmed by model number rather than by general type
• Service network able to carry out the mandated five-year overhaul and load test without shipping the whole assembly ashore
• Clear parts traceability for brake linings and release gear components, given their direct safety-critical role

Never treat a passed annual operational test as proof the on-load release gear is safe — most fatal release incidents happened on gear that had passed its most recent routine test, which is why the five-year thorough examination and load test exist as a separate, deeper check.