49er (dinghy)

The 49er's name comes from its hull length of . It incorporates ideas developed in Julian Bethwaite's 18ft Skiffs, notably the Prime Computer series of boats, which were double handers. To handle a large and powerful sail area, the mast uses a square topped sail that causes the upper main to twist off and flatten, allowing a controllable sail with fast gust response and reducing the heeling moment. The use of solid wings, rather than tubes as on similar boats (RS800 etc.), makes it easier for the crew to run across the deck from gunwale to gunwale during maneuvers. The 49er made its first Olympic appearance at the Sydney Olympics in 2000 and has continued to grow in popularity ever since. With a Portsmouth yardstick Handicap of 740 the 49er is the fastest two person one-design monohull dinghy. In 2009 the boat received a new rig design, including a larger fully carbon mast (replacing the aluminum mast) and square top (roach) mainsail. ==Construction==

As a one design class, the 49er has two licensed suppliers, Mackay Boats in Oceania and Ovington in Europe. Hull The hull is made of Epoxy GRP and foam sandwich laminate with carbon fibre in high load areas. It includes two solid wings, also called racks, that clip into the side to increase righting moment of the trapezing crew. Its length was fixed at 4.99 metres because the ISAF brief for the high performance Olympic class dinghy called for a 5-metre boat, but Tokao Otani, a member of the development consortium, pointed out that there was a tariff in Japan for boats over 5 metres long. It has a fine entry to efficiently transition between the low speed displacement, and high speed planing modes. According to the International 49er class rules, the minimum hull weight including all permanent fittings can not be less than 94.0 kg. Spars Southern Spars, part of the North Technology Group, is the licensed supplier of the 49er mast. It is a three piece male-moulded assembly made from 100% standard modulus carbon. It is 7.0 metres tall and capable of supporting a combined crew weight up to 165 kg from its dual trapeze. The mast is braced by three sets of shrouds that connect to a fitting on the side of the boat. The crew is able to adjust them by tightening or loosening them, depending on the wind speed and sea states. The boom is made from an aluminium alloy extrusion. Foils The rudder and daggerboard are made from a composite of epoxy, carbon and glass, covered by a hard gelcoat surface. The head of each class legal foil carries the embossed 49er logo and the ICA label. Sails The 49er carries three sails: a mainsail, jib, and spinnaker. The main and jib combined are 20 square metres, fully battened and made of reinforced Mylar (film polyester). The main was redesigned in 2007 from a full, curved roach plan to having a square on top in order to provide more sail area and to control more shape adjustment. The spinnaker is 38 square metres in a tri-radial asymmetric shape. ==Events==

Olympics Men's 49er Women's 49er FX World Championships Men's 49er Women's 49er FX ==Related boats==

The 49erFX was developed by Mackay Boats to be a women's Olympic class. It consists of a 49er hull, wings, and foils, with a scaled down rig designed to suit the weight of an elite female crew. The 29er is a smaller, single trapeze trainer to the 49er. It has become popular in North America, Europe and Australia as a fast youth boat. Recently the 29erXX, a twin trapeze version of the 29er, has been produced with a rig very similar to the 49er. The 59er dinghy was put into production in Australia and the UK in 2002. It is a non-trapeze, sailing dinghy, rigged with an asymmetrical spinnaker. It is designed for a crew weight of . ==References==