A davit (// or //) is a structure, usually made of steel, which is used to lower things over an edge of a long drop-off, such as scaffolding down a building exterior or launching a lifeboat over the side of a ship.
The development of the davit from its original "goose neck form" to the current devices advanced greatly when A.P. Schat patented a number of systems in 1926 that allowed the lifeboat to glide over obstructions on a ship's hull, known as the "Schat Skate". This was followed by a self-braking winch system that allowed the lifeboat to be lowered evenly.
Davits have always been designed to fit into deck spaces that the naval architects deemed necessary and a variety of designs emerged:
- GRA - Gravity roller track davit (Miranda) – usually above promenade decks.
- SPG - Single pivot gravity davit (Radial) – for many different deck spaces.
- FFD - Free fall davit – For free fall lifeboats on stern
- QD - Quadrantal davit – Old mechanical style, often hand cranked into outboard position
The standard became so common that shipyard specifications call for Schat type davits from whatever source.
Davits can also refer to single mechanical arms with a winch for lowering life rafts and raising spare parts onto a vessel.
Recent developments are based on aft-launched ramps where the lifeboat is allowed to free fall, as opposed to being lowered by a winch, into the ocean. Thus its name, free fall lifeboat, is apparent. Similar systems developed by Schat companies are used on offshore oil/gas rigs placed around the structure.
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