The AC72 (America's Cup 72 class) is a class of

wingsail A wingsail, twin-skin sail or double skin sail is a variable-Camber (aerodynamics), camber aerodynamic structure that is fitted to a marine vessel in place of conventional sails. Wingsails are analogous to Wing, airplane wings, except that they ...

catamaran A catamaran () (informally, a "cat") is a watercraft with two parallel hull (watercraft), hulls of equal size. The wide distance between a catamaran's hulls imparts stability through resistance to rolling and overturning; no ballast is requi ...

s built to a box rule, which governs the construction and operation of yachts competing in the 2013

Louis Vuitton Louis Vuitton Malletier SAS, commonly known as Louis Vuitton (, ), is a French Luxury goods, luxury fashion house and company founded in 1854 by Louis Vuitton (designer), Louis Vuitton. The label's LV monogram appears on most of its products, ...

and the

America's Cup The America's Cup is a sailing competition and the oldest international competition still operating in any sport. America's Cup match races are held between two sailing yachts: one from the yacht club that currently holds the trophy (known ...

races. The class was subsequently replaced by the smaller AC50 class.

Background

Following the 2010 America's Cup, where the Golden Gate Yacht Club's '' USA 17''

trimaran A trimaran (or double-outrigger) is a multihull boat that comprises a main hull and two smaller outrigger hulls (or "floats") which are attached to the main hull with lateral beams. Most modern trimarans are sailing yachts designed for recrea ...

defeated the catamaran ''

Alinghi 5 ''Alinghi 5'' is a (waterline length, LWL), beam sloop-rigged catamaran built by Alinghi for the America's Cup (33rd edition), 33rd America's Cup. The boat was launched on 8 July 2009 when the hull was lifted from the construction shed in Vi ...

'', it was decided by the winners that the next

competition would be sailed in catamarans in the hope of making the sport more attractive to television audiences. At the same time a smaller sister class, the AC45, was developed to allow teams to practice and adjust to the new formula as well as create a greater exposure of sailing to the general public with the America's Cup World Series.

Specifications

The AC72 has the following maximum specifications: *Overall length: *Waterline length: *Beam: *Weight: *Maximum draught: *Crew: 11 Maximum speed Using foils for the first time in the America's Cup the AC72 was expected to sail faster than the wind: upwind at 1.2 times the speed of the true wind, and downwind at 1.6 times the speed of the true wind. But in fact it proved faster, averaging about 1.8 times the speed of the wind with peaks slightly over 2.3. A multiple of 2.79 times wind speed was achieved by Emirates Team New Zealand in practice, which sailed at 44.15 knots (81 km/h, 50 mph) in 15.8 knots of wind on July 18, 2013. Typical racing speeds are over 30 knots (55 km/h, 34 mph) with the boats capable of sailing well over 40 knots (74 km/h, 46 mph) in the right conditions. The fastest race speed recorded was on Emirates Team New Zealand which was 47.57 knots (88 km/h, 55 mph) in 21.8 knots of wind (2.2 times the wind speed) on September 24, 2013. Features * Pedestals * Multi speed winches * Backstays * Crossbeams * Wing Pod * Digital Performance Indicators * Soft Sails * Wing-controlled cables * Three separate cockpits * Buttons on wheels

In competition

The boats have been used in the 2013 Louis Vuitton Cup and the 2013 America's Cup. By mid-June 2013, all boats had "lined up" and conducted trials against each other on the planned race track in

San Francisco Bay San Francisco Bay (Chochenyo language, Chochenyo: 'ommu) is a large tidal estuary in the United States, U.S. state of California, and gives its name to the San Francisco Bay Area. It is dominated by the cities of San Francisco, California, San ...

, notably Oracle Team USA vs. Artemis Racing and Emirates Team New Zealand vs. Luna Rossa Challenge.

List of AC72 catamarans

Incidents

On 17 October 2012, Oracle Racing's AC72 pitchpoled (somersaulted) and capsized, causing severe damage to the yacht. The wingsail was completely destroyed while being swept under the

Golden Gate Bridge The Golden Gate Bridge is a suspension bridge spanning the Golden Gate, the strait connecting San Francisco Bay and the Pacific Ocean in California, United States. The structure links San Francisco—the northern tip of the San Francisco Peni ...

by a strong ebb tide. On 9 May 2013, Artemis Racing's AC72 pitchpoled and broke apart, resulting in the death of crew member Andrew Simpson. The other two teams, Luna Rossa Challenge, and Team New Zealand, both suffered minor setbacks, including hitting seals and damaging their wing sails, resulting in loss of sailing time.

References

External links

{{2013 America's Cup America's Cup yachts Catamarans Box rule sailing classes 2013 America's Cup