Davit

From Wikipedia, the free encyclopedia
For the name of a person, see David (name).
Boat suspended from davits

A davit (/ˈdævɨt/ or /ˈdeɪvɨt/) is a structure, usually made of steel, which is used to lower things over the edge of a long drop-off, such as scaffolding down a building exterior[1] or launching a lifeboat over the side of a ship. Davits can also refer to single mechanical arms with a winch for lowering life rafts and raising spare parts onto a vessel.

Development

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. The standard became so common that shipyard specifications call for Schat type davits from whatever source. Similar systems developed by Schat companies are used on offshore oil/gas rigs placed around the structure.

Types

Davits are 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

  • Davit (for starboard boat)

  • Davit (for rescue boat)

  • Davits holding rescue vessel on starboard of North Sea ferry

  • Gravity davit

References

  1. ↑ http://www.atslab.com/fall-protection/davit-systems-and-inspections.php
Look up davit in Wiktionary, the free dictionary.
This article is issued from Wikipedia. The text is available under the Creative Commons Attribution/Share Alike; additional terms may apply for the media files.