A catamaran is a type of boat (or occasionally ship) consisting of
two hulls joined by a frame. Catamarans can be sail- or motor-powered.
The word catamaran comes from the Tamil language, in which the word
kattumaram means "logs bound together". The catamaran was
the invention of the paravas, an aristocratic fishing community in the
southern coast of Tamilnadu, India. Catamarans were used by the ancient
Tamil Chola dynasty as early as 5th century AD for moving their fleets
to conquer such south-east Asian regions as Burma, Indonesia and Malaysia.
Catamarans are a relatively recent design of boat for both leisure and
sport sailing, although they have been used for millennia in Oceania,
where Polynesian catamarans allowed seafaring Polynesians to settle
the world's most far-flung islands. Catamarans have been met by a degree
of scepticism from some sailors accustomed to more "traditional"
designs.
Catamaran sailing
Although the principles of sailing are the same for both catamarans
and monohulls, there are some 'peculiarities' to sailing catamarans.
For example:
Catamarans can be harder to tack (turn through the wind). Because they
are lighter in proportion to their sail size, they have less momentum
to carry them through the turn when they are head to wind.
They have a higher average speed.
All boats sail faster when travelling in certain directions relative
to the wind the best speeds typically being achieved when heading away
from the wind at about 135 degrees. This effect is much more noticeable
with catamarans, even to the extent that it can be more efficient to
jibe ('tack' downwind) in zig zags, rather than heading directly away
from the wind as a monohull would.
Catamarans are less likely to capsize in the classic 'beam-wise' manner
but often have a tendency to 'pole-axe' (or 'pitchpole') instead - where
the leeward (downwind) bow sinks into the water and the boat 'trips'
over forward, leading to a capsize.
Teaching for new sailors is usually carried out in monohulls as they
are thought easier to learn to sail, a mixture of all the differences
mentioned probably contributes to this.
Stars & Stripes, a racing catamaranCatamarans, and multihulls in
general, are normally faster than single-hull boats for four reasons:
each hull of a catamaran is (typically) thinner in cross section than
those of monohulls;
catamarans are lighter due to the fact there is no keel counterweight.
catamarans have a wider beam (the distance from one side of the boat
to the other), which makes them more stable and therefore able to carry
more sail area per metre of length than an equivalent monohull.
the greater stability means that the sail is more likely to stay upright
in a gust, drawing more power than a monohull's sail which is more likely
to lean over.
Catamarans are especially favourable in coastal waters, where the open
spaces permit the boat to reach and maintain its maximum speed. Catamarans
make good cruising and long distance boats: The Race (around the world,
in 2001) was won by the giant catamaran Club Med skippered by Grant
Dalton. It went round the earth in 62 days at an average speed of eighteen
knots.
The Hobie cats
International A-Class (open design; length 5.49 m (18 ft), beam 2.3
m (7 ft 6.5 in), weight 75 kg, sail 13.94 m² (150 ft²))
Dart 15 and Dart 18
Tornado, Olympic class racing catamaran.
Catamarans for ferries:
Stena Line HSS class (High-speed Sea Service)
Stena Discovery - Harwich, UK to Hoek van Holland, Netherlands
Stena Voyager - Stranraer to Belfast
Stena Explorer - Holyhead to Dun Laoghaire, Republic of Ireland
Lake Express running between Milwaukee, Wisconsin and Muskegon, Michigan
Spirit of Ontario I running between Rochester, New York and Toronto,
Ontario
SSTH Ocean Arrow
SuperStar Express, P&O Irish Sea running between Troon, Scotland
and Belfast, Northern Ireland.
FoilCat, FlyingCat and Tricat operated by Turbojet Ferry, running between
Hong Kong and Macau.
The Cat, a high speed car ferry running various routes between Canada's
Atlantic provinces and the mainland, which includes a line between Portland,
Maine in the United States and Yarmouth, Nova Scotia in Canada.
A modern interpretation of the traditional catamaran can be found at
[1], designed by James Wharram.
EMERGENCE OF THE POWER CATAMARAN
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