Freefall Launch Platform

What makes a freefall launch platform different from a gravity davit

A gravity davit lowers a lifeboat on wire falls, under a winch brake, at a controlled speed the whole way to the water. A freefall arrangement does something deliberately more aggressive: the lifeboat sits on an inclined ramp at the stern, held by a single release hook, and when that hook is triggered from inside the boat the boat slides down the ramp under its own weight and leaves the ramp end in free fall, hitting the water bow-first with enough momentum to drive itself clear of the ship's side before the engine is even started. That design exists specifically for the worst case, a ship on fire, listing, or still making way, where crew cannot safely stand at davits to lower a boat under control and need to get away in one uninterrupted motion. Occupants are secured in seats with harnesses because the fall and water entry produce real deceleration loads that a standing or unsecured occupant would not survive well.

Main components

Ramp and cradle

A fixed, angled steel ramp at the stern with a cradle or skid that holds the boat in its stowed position and guides it during the slide, angled and finished to give the boat the release speed the type approval testing was based on.

Release mechanism

A single on-load release hook holding the boat at the top of the ramp, triggered by a control inside the boat itself, deliberately kept independent of any winch or wire system so a power or hydraulic failure elsewhere on the launching appliance cannot prevent release.

Secondary lowering arrangement

Many installations also provide a davit-launch or lowering mode using the same appliance, allowing the boat to be lowered under winch control for training, maintenance recovery, or a controlled launch when freefall conditions are not needed, without altering the primary freefall capability.

Retrieval winch

A powered winch and wire system to recover the boat back up the ramp after use or drill, separate in function from the release mechanism even where they share some structure.

Securing gripes and hydraulic dampers

Gripes or lashings hold the boat firmly on the ramp against ship motion at sea, released as part of the launch sequence, while some installations include a hydraulic damper at the ramp end to manage the transition from slide to free fall consistently regardless of sea state.

Selection and sizing

Ramp angle and length, boat weight, and the height of the stern above the waterline are all fixed together during type approval testing, so a freefall boat and its launching appliance are certified as a matched set rather than components chosen independently. Selecting a system means matching boat capacity to the complement it must carry, and checking that the vessel's actual freeboard at the stern falls within the range the appliance and boat were tested for, since a mismatch changes the entry speed and angle the boat was designed around.

Regulations and class

The LSA Code sets the design, testing and launching performance requirements for freefall lifeboats and their launching appliances, including the drop test height and entry conditions the combination must be proven against before certification. Class surveys require periodic winch load testing, release gear function tests, and a full launch drill at intervals set by SOLAS and the LSA Code, with the on-load release hook specifically checked for free and correct operation since a hook that will not release under load defeats the entire system.

Typical faults

What to look for in a supplier

• Boat and launching appliance supplied and certified as a matched, type-approved set, since substituting components from different manufacturers can void the approval basis
• Documented ramp angle and freeboard compatibility for the specific vessel, not a generic installation drawing
• Full-load release hook testing included as standard commissioning and periodic service, not left to the crew to arrange separately
• Accessible, serviceable retrieval winch arrangement, since a system that is hard to service after a drill discourages the regular drilling the crew actually needs

Insist on seeing the on-load release hook exercised under actual load during commissioning, not just cycled by hand with the boat empty, because a hook that moves freely with no load can still bind under the boat's full weight.