History
Catamarans fromEtymology
The word "catamaran" is derived from the Tamil word, ''Development in Oceania and Asia
left, Succession of forms in the development of the Austronesian boat (Mahdi, 1999) Catamaran-type vessels were an early technology of theTraditional catamarans
The following is a list of traditional Austronesian catamarans: *Western development of sailing catamarans
Nathaniel Herreshoff's long catamaran, ''Duplex'', on the —built in 1877">River Thames—built in 1877 The first documented example of double-hulled sailing craft inPerformance
Catamarans have two distinct primary performance characteristics that distinguish them from displacement monohull vessels: lower resistance to passage through the water and greater stability (initial resistance to capsize). Choosing between a monohull and catamaran configuration includes considerations of carrying capacity, speed, and efficiency.Resistance
At low to moderate speeds, a lightweight catamaran hull experiences resistance to passage through water that is approximately proportional to the square of its speed. A displacement monohull, by comparison, experiences resistance that is at least the cube of its speed. This means that a catamaran would require four times the power in order to double its speed, whereas a monohull would require eight times the power to double its speed, starting at a slow speed. For powered catamarans, this implies smaller power plants (although two are typically required). For sailing catamarans, low forward resistance allows the sails to derive power from attached flow, their most efficient mode—analogous to a wing—leading to the use of wingsails in racing craft.Stability
Catamarans rely primarily on form stability to resist heeling and capsize. Comparison of heeling stability of a rectangular-cross sectionTradeoffs
''Vangohh Seafarer'', a catamaran motor yacht berthed at Straits Quay, Georgetown, Pulau Pinang, Malaysia One measure of the trade-off between speed and carrying capacity is the displacement Froude number (FnV), compared with ''calm water transportation efficiency''. FnV applies when theSWATH and wave-piercing designs
A SWATH ship has twin hulls (blue) that remain completely submerged Two advances over the traditional catamaran are the '' small-waterplane-area twin hull'' (SWATH) and the ''wave-piercing'' configuration—the latter having become a widely favored design. SWATH reduces wave-generating resistance by moving displacement volume below the waterline, using a pair of tubular, submarine-like hulls, connected by pylons to the bridge deck with a narrow waterline cross-section. The submerged hulls are minimally affected by waves. The SWATH form was invented by Canadian Frederick G. Creed, who presented his idea in 1938 and was later awarded a British patent for it in 1946. It was first used in the 1960s and 1970s as an evolution of catamaran design for use as oceanographic research vessels orApplications
upEmirates Team New Zealand's AC72 ''Aotearoa'' on foils in San Francisco Bay '' '', a wave-piercing solar-powered cruising trimaran in Hamburg, Germany">Tûranor PlanetSolar'', a wave-piercing solar-powered cruising trimaran in Hamburg, Germany A catamaran configuration fills a niche where speed and sea-kindliness is favored over bulk capacity. In larger vessels, this niche favors car ferries and military vessels for patrol or operation in the littoral zone.Sport
left, , an ocean-racing catamaran">Gitana 13, an ocean-racing catamaran Recreational and sport catamarans typically are designed to have a crew of two and be launched and landed from a beach. Most have a trampoline on the bridging structure, a rotating mast and full-length battens on the mainsail. Performance versions often have trapezes to allow the crew to hike out and counterbalance capsize forces during strong winds on certain points of sail. For the 33rd America's Cup, both the defender and the challenger built long multihulls.Cruising
left, A cruising catamaran Cruising sailors must make trade-offs among volume, useful load, speed, and cost in choosing a boat. Choosing a catamaran offers increased speed at the expense of reduced load per unit of cost. Howard and Doane describe the following tradeoffs between cruising monohulls and catamarans: A long-distance, offshore cruising monohull may be as short as for a given crew complement and supporting supplies, whereas a cruising catamaran would need to be to achieve the same capacity. In addition to greater speed, catamarans draw less water than do monohulls— as little as —and are easier to beach. Catamarans are harder to tack and take up more space in a marina. Cruising catamarans entail added expense for having two engines and two rudders. Tarjan adds that cruising catamarans boats can maintain a comfortable per day passage, with the racing versions recording well over per day. In addition, they do not heel more than 10-12 degrees, even at full speed on a reach. Powered cruising catamarans share many of the amenities found in a sail cruising catamaran. The saloon typically spans two hulls wherein are found the staterooms and engine compartments. As with sailing catamarans, this configuration minimizes boat motion in a seaway. The Swiss-registered wave-piercing catamaran, '' Tûranor PlanetSolar'', which was launched in March 2010, is the world's largestPassenger transport
The 1970s saw the introduction of catamarans as high-speed ferries, as pioneered by Westermoen Hydrofoil inMilitary
US Naval Ship ''Spearhead'' (JHSV-1) during sea trials in 2012 The first warship to be propelled by a steam engine, named ''Demologos'' or ''Fulton'' and built in the United States during theSee also
*References
Further reading
* {{Authority control Naval architecture Shipbuilding * Multihulls Nautical terminology Austronesian culture