Index card 21

http://en.wikipedia.org/wiki/Davit

• A davit, (dāv'ĭt, dā'vĭt), is a structure, usually made of steel, which is used to lower things over an edge of a long drop off such as lowering a maintenance trapeze down a building or launching a lifeboat over the side of a ship.
• GRA - Gravity Roller track davit - usually above promenade decks.
• SPG - Single pivot gravity davit - for many different deck spaces.
• Davits can also refer to single mechanical arms with a winch for lowering life rafts and raising spare parts onto a vessel.