28 July 2005
Additional information (such as tabular data and figures) on mooring hardware is
contained in UFC 4-159-03, UFC 4-150-08, and TR-6014-OCN. The following
are the most commonly used types of mooring hardware:
A bollard is a short single-column cast-steel fitting that extends up from a
baseplate that is secured to a strong point of a shore structure or berthing facility.
Bollards are used in snubbing or checking the motion of a ship being moored, by
tightening and loosening mooring lines that are fastened to them. Bollards are
also used for securing a ship that has been placed in its final moored position.
Do not use bollards without ears in facilities where a high vertical angle of the
mooring line is anticipated, to prevent lines from slipping off.
Bitts are short, double-column, cast-steel fittings fastened to the deck of berthing
facilities. They are used to snub and secure a vessel. The double-columns allow
for convenient and rapid tying and releasing of mooring lines, as well as for
guiding a line through to other hardware.
Currently, available cleats are low-capacity, cast steel deck fittings having two
projecting arms that are intended to be used for securing mooring lines of small
craft. They are provided at most naval facilities. Given a choice, line-handling
crews will use cleats in preference to bollards or bitts, even for large ships, as the
possibility of line slippage is remote. However, cleats can easily be overloaded
when they are used in lieu of major fittings such as bollards. Because of the low
holding capacity of cleats, they should not be used in combination with higher
capacity deck fittings.
Chocks are either stationary or roller-equipped cast deck fittings that are used to
train the direction of a mooring line. Chocks are available either open at the top,
permanently closed, or closed by a hinged closing piece.
Ships outfitted with winch-mounted wire rope mooring lines require greater
pulling power than can be provided by one or two deck hands to draw out the
ship's lines. The assignment is handled by capstans mounted along the face of
the wharf. The capstans are small electric winches of 5 to 10 hp with a drum
rotating about a vertical axis. The capstan is used by a deck hand that receives a
messenger line at the end of which is fastened the sling of the wire rope hawser.