mainmast n : the chief mast of a sailing vessel with two or more masts

English

Noun

1. The chief, and tallest mast of a sailing ship that has more than one mast

Translations

Usage notes

• On a ship with three or more masts, it is the second mast from the bow

The mast of a sailing ship is a tall vertical pole which supports the sails. Larger ships have several masts, with the size and configuration depending on the style of ship.

Until the 20th century, a ship's masts would be wooden spars, originally constructed from a single straight tree trunk. As ship sizes increased, taller masts were constructed by lashing up to three spars together.

A ship's masts are named from bow to stern (front to back):

• Fore-mast - the first mast, or the mast fore of the main-mast.
  • Sections: Fore-mast lower — Fore topmast — Fore topgallant mast
• Main-mast - the tallest mast, usually located near the center of the ship.
  • Sections: Main-mast lower — Main topmast — Main topgallant mast — royal mast (if fitted)
• Mizzen-mast - the third mast, or the mast immediately aft of the main-mast. Typically shorter than the fore-mast.
  • Sections: Mizzen-mast lower — Mizzen topmast — Mizzen topgallant mast
• Bonaventure mizzen - the fourth mast on larger Sixteenth Century galleons, typically lateen-rigged and shorter than the main mizzen.
• Jigger-mast - the fourth mast or the aft-most mast where it is smallest on vessels of less than four masts.
  • Sections: Jigger-mast lower — Jigger topmast — Jigger topgallant mast

Mast names for other vessels generally follow this naming.

Many ships would also have a bowsprit at an angle closer to the horizontal extending forward of the prow.

Most types of ships with two masts would have a main-mast and a smaller mizzen-mast, although both brigs and two masted schooners instead carry a fore-mast and main-mast. On a two-masted vessel with the mainmast forward and a much smaller second mast, such as a ketch, or particularly a yawl, the terms mizzen and jigger are synonymous.

Some two-masted schooners have masts of identical size, but the aftmost is still referred to as the main-mast, and normally has the larger course. Schooners have been built with up to seven masts in all, with several six-masted examples.

On square rigged vessels, each mast carries several horizontal yards from which the individual sails are hung, see also rigging.

Modern masts

Although sailing ships had been superseded by engine powered ships in the 19th century, recreational sailing ships and yachts continue to be designed and constructed. In the 1930s aluminium masts were introduced on large J-class yachts. Aluminium has considerable advantages over wooden masts, being lighter, stronger and impervious to rot. Also, an aluminium mast can be extruded as a single piece for the entire height as the mast.

After the Second World War, extruded aluminium masts became common on all dinghies and smaller yachts. Higher performance yachts would use tapered aluminium masts, constructed by removing a triangular strip of aluminium along the length of the mast and then closing and welding the gap.

From the mid 1990s racing yachts introduced the use of carbon fibre and other composite materials to construct masts with even better strength to weight ratios. Carbon fibre masts could also be constructed with more precisely engineered aerodynamic profiles.

Modern masts form the leading edge of a sail's airfoil and tend to have a teardrop-shaped cross-section. On smaller racing yachts and catamarans, the mast rotates to the optimum angle for the sail's airfoil. If the mast has a long, thin cross-section and makes up a significant area of the airfoil, it is called a wing-mast; boats using these have a smaller sail area to compensate for the larger mast area.

On modern warships, the mast still exists but does not serve the purpose of holding sails, since all modern warships are engine-powered. Instead, the mast serves as a mounting point for radar and telecommunication antennas.

See also

• Sailing ship
• Rigging
• Sail-plan

References

• http://www.bluewatersailing.com/shipclass.php
• http://www.hms-trincomalee.co.uk/virtual/rigging/sailsrev.htm
• http://tallships.sailtraining.org/sailrigs.htm
• http://boatdesign.net/articles/mast-materials/