The term to square a yard is used when sailing a
square-rigged ship.
To "square a yard" is to lay the
yards
The yard (symbol: yd) is an English unit of length in both the British imperial and US customary systems of measurement equalling 3 feet or 36 inches. Since 1959 it has been by international agreement standardized as exactly ...
at right angles to the line of the
keel
The keel is the bottom-most longitudinal structural element of a watercraft, important for stability. On some sailboats, it may have a fluid dynamics, hydrodynamic and counterbalancing purpose as well. The keel laying, laying of the keel is often ...
by
trim
Trim or TRIM may refer to:
Cutting
* Cutting or trimming small pieces off something to remove them
** Book trimming, a stage of the publishing process
** Pruning, trimming as a form of pruning often used on trees
Decoration
* Trim (sewing), or ...
ming with the
braces.
Explanation
"Squaring a yard" adjusts the position of the square sails so that they are perpendicular to the keel of the ship. This is done in order to "run before the wind', i.e., sail with the wind directly behind the vessel rather than
tacking.
When a square-rigger is
running downwind, and the yards are positioned perpendicular to the line of the keel, both sheets that control the yard (braces) are tied off aft (i.e., straight back), leading to the figurative phrase "Both sheets aft."
"Both sheets aft, The situation of a square-rigged ship that sails before the wind, or with the wind right astern. It is said also of a half-drunken sailor rolling along with his hands in his pockets and elbows square."
[
]
Further definition
"Square ... A term peculiarly appropriated to the yards and their sails. Thus, when the yards hang at right angles with the mast they are said to be 'square by the lifts;' when perpendicular to the ship's length, they are 'square by the braces;' but when they lie in a direction perpendicular to the plane of the keel, they are 'square by the lifts and braces.' The yards are said to be very square when they are of extraordinary length, and the same epithet is applied to their sails with respect to their breadth."
See also
*
Square rig
Square rig is a generic type of sail plan, sail and rigging arrangement in which a sailing ship, sailing vessel's primary driving sails are carried on horizontal spar (sailing), spars that are perpendicular (or wikt:square#Adjective, square) to t ...
*
Full-rigged ship
A full-rigged ship or fully rigged ship is a sailing ship, sailing vessel with a sail plan of three or more mast (sailing), masts, all of them square rig, square-rigged. Such a vessel is said to have a ship rig or be ship-rigged, with each mas ...
*
Running downwind
*
Yard (sailing)
A yard is a spar (sailing), spar on a mast (sailing), mast from which sails are set. It may be constructed of timber or steel or from more modern materials such as aluminium or carbon fibre. Although some types of fore and aft rigs have yards, t ...
*
Braces (sailing)
A brace on a square-rigged ship is a rope (''line'') used to rotate a yard around the mast, to allow the ship to sail at different angles to the wind. Braces are always used in pairs, one at each end of a yard (''yardarm''), termed port brace an ...
References
{{reflist
Nautical terminology