Sail-plan - Types of Ships

Types of Ships

Sailboat types may be distinguished by:

• hull configuration (monohull, catamaran, trimaran),
• keel type (full, fin, wing, centerboard etc.),
• purpose (sport, racing, cruising),
• number and configuration of masts
• sail plan (square and/or fore and aft rigged sails).

• Proa: constructed using stone age tools, variations on the crab claw sail rig on various sized open ocean canoes carried the Pacific island navigators on regular long range trips. Both ends are alike, and the boat is sailed in either direction, but it has a high windward side and a lower leeward side supported by an outrigger.

• Sunfish: a variation on the proa with a single unstayed mast and a single sail, which uses upper and lower spars like a crab claw sail but which pivots around the mast like a lateen. The usage of two straight spars allows for the sails to be cut straight without any camber factored in, making the sails considerably simpler to manufacture.

• Catboat: a sailboat with a single mast and single sail, usually gaff-rigged. This is the easiest sail-plan to sail, and is used on the smallest and simplest boats. The catboat is a classic fishing boat. A popular movement among home-built boats uses this simple rig to make "folk-boats." One of the advantages of this type is that it can be rigged with no boom to hit one's head or knock one into the water. However, the gaff requires two halyards and often two topping lifts. The weight of the gaff spar high in the rigging can be undesirable. The gaff's fork (jaws) is held on by a rope threaded through beads called trucks (US) or parrel beads (UK). The gaff must slide down the mast, and therefore prevents any stays from bracing the mast. This usually makes the rig even heavier, requiring yet more ballast.

• Gunter: a rig designed for smaller boats where the mast is often taken down. It consists of a relatively short mast (usually slightly shorter than the boat so that it can be stowed inside) and a long gaff (often only slightly shorter than the mast). However, rather than the usual trapezoidal shape of a gaff sail, it is triangular, like a Bermuda rig. This allows the gaff, when hoisted, to pivot upwards until it is vertical, effectively forming an extension to the mast. Thus a decent-sized sailing rig can be added to the boat while still allowing all the equipment to be stowed completely inside it. The popular Mirror class of dinghy is gunter rigged for this reason.

• Sloop: a Bermuda or gaff mainsail lifted by a single mast with a single jib bent onto the forestay, held taut with a backstay. The mainsail is usually managed with a spar on the underside called a "boom". One of the best-performing rigs per square foot of sail area and is fast for up-wind passages. This rig is the most popular for recreational boating because of its potential for high performance. On small boats, it can be a simple rig. On larger sloops, the large sails have high loads, and one must manage them with winches or multiple purchase block-and-tackle devices.

• Cutter: like a sloop with two or more headsails in the foretriangle. Better than a sloop for light winds, it is also easier to manage, due to the sail area being split up between smaller sails which require less force to trim as compared to the larger single jib of the sloop. The mast is located at about 50% of boat length.

• Yawl: like a sloop or catboat with a mizzen mast located aft (closer to the stern of the vessel) of the rudder post. The mizzen is small, and is intended to help provide helm balance.

• Ketch: like a yawl, but the mizzenmast is often much larger, and is located forward of the rudder post. The purpose of the mizzen sail in a ketch rig, unlike the yawl rig, is to provide drive to the hull. A ketch rig allows for shorter sails than a sloop with the same sail area, resulting in a lower center of sail and less overturning moment. The shorter masts therefore reduce the amount of ballast and stress on the rigging needed to keep the boat upright. Generally the rig is safer and less prone to broaching or capsize than a comparable sloop, and has more flexibility in sailplan when reducing sail under strong crosswind conditions—the mainsail can be brought down entirely (not requiring reefing) and the remaining rig will be both balanced on the helm and capable of driving the boat. The ketch is a classic small cargo boat.

• Schooner: a fore-and-aft rig having at least two masts, with a foremast that is usually smaller than the other masts. Schooners have traditionally been gaff-rigged and in small craft are generally two-masted, however many have been built with Marconi rigs (and even junk rigs) rather than gaffs and in the golden age of sail, vessels were built with as many as seven masts. One of the easiest types to sail, but performs poorly to windward without gaff topsails. The extra sails and ease of the gaff sails make the rig easier to operate, though not necessarily faster, than a sloop on all points of sail other than up-wind. Schooners were more popular than sloops prior to the upsurge in recreational boating. The better performance of the sloop upwind was outweighed for most sailors by the better performance of the schooner at all other, more comfortable, points of sail. Advances in design and equipment over the last hundred years have diminished the advantages of the schooner rig. Many schooners sailing today are either reproductions or replicas of famous schooners of old.

• Topsail Schooner: a schooner having one or more square-rigged sails on its foremast, but still having gaff-rigged main sails on all masts.

• Brig: two masts, both square-rigged with a spanker on the mainmast.

• Hermaphrodite Brig or Schooner Brig: two masts, square-rigged on the foremast and fore-and-aft rigged on the mainmast.

• Brigantine: two masts, square-rigged on the foremast, staysails between the masts and gaff mailsail with square topsails on the mainmast.

• Barquentine: is a three masted vessel, square rigged on the foremast and fore-and-aft rigged on the main and mizzen masts. Some sailors who have sailed on them say it is a poor-handling compromise between a barque and a ship, though having more speed than a barque or schooner.

• Barque: three masts or more, square rigged on all except the aftmost mast. Usually three or four masted but five masted barques have been built. Lower-speed, especially downwind, but requiring fewer sailors than a ship. This is a classic slow-cargo ship.

• Fully rigged Ship: three or more masts, square rigged on all, with stay-sails between. The classic ship rig originally had exactly three masts, but four and five masted ships were also built. The classic sailing warship—the ship of the line—was full rigged in this way, because of high performance on all points of wind. In particular, studding sails or topping sails could be easily added for light airs or high speeds. Square rigs have twice the sail area per mast height compared to triangular sails, and when tuned, more exactly approximate a multiple airfoil, and therefore apply larger forces to the hull. Windage (drag) is more than triangular rigs, which have smaller tip vortices. Therefore, historic ships could not point as far upwind as high performance sloops. However, contemporary marconi rigs (sloops, etc.) were limited in size by the strength of available materials, especially their sails and the running rigging to set them. Ships were not so limited, because their sails were smaller relative to the hull, distributing forces more evenly, over more masts. Therefore, due to their much larger, longer waterline length, ships had much faster hull speeds, and could run down or away from any contemporary sloop or other marconi rig, even if it pointed more upwind. Schooners have a heavier rig and require more ballast than ships, which increases the wetted area and hull friction of a large schooner compared to a ship of the same size. The result is that a ship can run down or away from a schooner of the same hull length. Ships were larger than brigs and brigantines, and faster than barques or barquentines, but required more sailors.

• Bragana or felucca: a classic in the Mediterranean or Indian Ocean. Three lateen sails in a row.

• Polacre: a three master with a narrow hull; carrying a square-rigged foremast, followed by two lateen sails. The same vessel, if she substituted her square-rigged mast with another lateen rigged one, would be called a xebec.

• Junk: the standard Chinese design: The sails are made flat with bamboo inserts (battens), permitting them to sail well on any point of sail. Easy to sail, and reasonably fast. The nature of the rig places no extreme loads anywhere on the sail or rigging, thus can be built using light-weight, less expensive materials. Some of the largest sailing ships ever constructed were junks for the Chinese treasure fleets. Junks also customarily had internal water-tight rooms, kept so by not having doors between them. Usually they were constructed of teak or mahogany.