Mast

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

 Other websites 
http://www.bluewatersailing.com/shipclass.php 
http://www.hms-trincomalee.co.uk/virtual/rigging/sails.htm 
http://tallships.sailtraining.org/sailrigs.htm 
http://boatdesign.net/articles/mast-materials/
Glossary of Nautical terms, sailing and boat parts 

Category:Ship building