Davit

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Boat suspended from mechanical davits

A davit is a system that is used to lower an emergency lifeboat to the embarkation level to be boarded. The davit has falls (now made of wire, used to be made of manilla) that are used to lower the lifeboat into the water.[1] Davits can also refer to single mechanical arms with a winch for lowering and raising spare parts onto a vessel.

Development[edit]

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 which are available from various sources. Similar systems developed by Schat companies are used on offshore oil or gas rigs, being placed around the structure.

Types[edit]

Davits are designed to fit into deck spaces that the naval architects deemed necessary:

  • Radial (obsolete) — Hand powered davit. This type was used on the RMS Titanic. Each arm must be rotated out manually; uses manila rope falls.
  • Mechanical (obsolete) — This type is like the radial davit, but both arms are moved out at the same time using a screw system; uses manila rope falls.
  • Gravity (industry standard) — There are multiple forms; one man can operate, and uses wire rope falls.
-Roller: Davit slides down a track, bringing the davit to the embarkation deck.
-Single pivot:  One pivot point where the lifeboat is moved over the side of the craft.
-Multi pivot:  Common on Promenade decks of cruise ships. Useful were space is limited.
-Free Fall:  Lifeboat slides right off of vessel. Lifeboat must be an enclosed type.
-Fixed:  Common on Oil Rigs. Lifeboat is hung above the water (at embarkation level) and lowered into the water.

Gallery[edit]

References[edit]

  1. ^ "Davit Systems | Applied Technical Services". Atslab.com. Retrieved 2014-02-21.