Davit

A davit is any of various cranelike devices used on a ship for supporting, raising, and lowering boats, anchors, etc.

Davit systems are most often used to lower an emergency lifeboat to the embarkation level to be boarded. Davits can also be used as man-overboard safety devices to retrieve personnel from the water.

The lifeboat davit has falls (now made of wire, historically of manila rope) that are used to lower the lifeboat into the water. Davits can also refer to single mechanical arms with a winch for lowering and raising spare parts onto a vessel and for lowering any other equipment from the deck of a vessel or a pontoon to the water. The maintaining and operation of davits is all under jurisdiction of International Maritime Organization. The regulations are enforced by the country's own Coast Guard.

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.

Development of the davit has also been in terms of material. Traditionally davits have been made in aluminium or steel but recent advances in composite material have led to the manufacture of davits in carbon fibre which has an excellent power to weight ratio. This means davits can be stowed away when not in use and the same davit used in multiple deck sockets fitted permanently on deck.

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

Liferaft: These can be Enclosed, partially enclosed, or open. (There are pictures of these on the page already so no description is added)

Frapping Lines: These lines are used on all davits except the fixed and freefall davits. The frapping line are used to pull the lifeboat over to the embarkation deck along with the tricing pendent to be loaded.

Gripes: Ropes used to hold the Lifeboat in the stored position while underway.

Tricing pendants: Lines used to initially pull the lifeboat over to the embarkation deck so that the Frapping lines can be connected.

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Wikipedia