Bitts are paired vertical wooden or metal posts mounted either aboard a ship or on a

wharf A wharf ( or wharfs), quay ( , also ), staith, or staithe is a structure on the shore of a harbour or on the bank of a river or canal where ships may dock to load and unload cargo or passengers. Such a structure includes one or more Berth (mo ...

pier A pier is a raised structure that rises above a body of water and usually juts out from its shore, typically supported by piling, piles or column, pillars, and provides above-water access to offshore areas. Frequent pier uses include fishing, b ...

, or

quay A wharf ( or wharfs), quay ( , also ), staith, or staithe is a structure on the shore of a harbour or on the bank of a river or canal where ships may dock to load and unload cargo or passengers. Such a structure includes one or more Berth (mo ...

. The posts are used to secure

mooring A mooring is any permanent structure to which a seaborne vessel (such as a boat, ship, or amphibious aircraft) may be secured. Examples include quays, wharfs, jetties, piers, anchor buoys, and mooring buoys. A ship is secured to a mooring to ...

lines,

rope A rope is a group of yarns, Plying, plies, fibres, or strands that are plying, twisted or braided together into a larger and stronger form. Ropes have high tensile strength and can be used for dragging and lifting. Rope is thicker and stronger ...

hawser Hawser () is a nautical term for a thick rope used in Mooring (watercraft), mooring or towing a ship. A hawser is not waterproof, as is a Nautical cable, cable. A hawser passes through a hawsehole, also known as a cat hole, located on the wikt: ...

s, or

cables Cable may refer to: Mechanical * Nautical cable, an assembly of three or more ropes woven against the weave of the ropes, rendering it virtually waterproof * Wire rope, a type of rope that consists of several strands of metal wire laid into a he ...

. Bitts aboard wooden sailing ships (sometime called cable-bitts) were large vertical timbers mortised into the keel and used as the

anchor An anchor is a device, normally made of metal, used to secure a vessel to the bed of a body of water to prevent the craft from drifting due to wind or current. The word derives from Latin ', which itself comes from the Greek (). Anch ...

cable attachment point. Bitts are carefully manufactured and maintained to avoid any sharp edges that might chafe and weaken the mooring lines.

Use

Mooring lines may be laid around the bitts either singly or in a figure-8 pattern with the

friction Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Types of friction include dry, fluid, lubricated, skin, and internal -- an incomplete list. The study of t ...

against tension increasing with each successive turn. As a verb ''bitt'' means to take another turn increasing the friction to slow or adjust a mooring ship's relative movement. Mooring fixtures of similar purpose: * A

bollard A bollard is a sturdy, short, vertical post. The term originally referred to a post on a ship or quay used principally for mooring boats. In modern usage, it also refers to posts installed to control road traffic and posts designed to pre ...

is a single vertical post useful to receive a spliced loop at the end of a mooring line. * A cleat has horizontal horns.Knight, p.788

References

{{Sailing ship elements Watercraft components