A glimpse at the development of wing masts
Text: Guy Delafontaine
The Little America’s Cup started in 1960. Indeed that year, in the United States, the Eastern Multihull Sailing Association had been challenged by the Chapman Sands Sailing Club based in Canvey Island near London, for a series of seven regattas that would form a new competition, «the International Catamaran Challenge Trophy », also known as the Little America’s Cup.
The Seacliff Yacht Club of Long Island, USA was to organize the races on the brand new C Class catamarans for the summer 1961. The Defender (from USA) was Wildcat with John Beery and John Hickok, against the Challenger Hellcat II with John Fisk and the famous Scottish designer Rod Macalpine-Downie. The two boats had used traditional fabric sails. Having won 4:1, John Fisk brought the Cup back to Europe. Hellcat II had been built in Brightlingsea (GB) in Reg White’s shipyard Sailcraft. Reg would later win the gold medal at the 1976 Olympics.
As it turned out, the C class cats were catamarans for millionaires: the design, the building, the tuning, the maintenance and the many adaptations and modifications ruined more than one. The Cup was won by Englishmen for eight consecutive years and subsequently remained in England.
As early as 1964…
The first-ever wing mast, developed in the US by George Patterson, appeared on “Sprinter” in the 1964 world championships, reaching overwhelming speed. It immediately inspired Australian naval architects Charles and Lindsay Cunningham, Danish Paul Elvström and Gert Fredericksen, UK Rodney March and Rod Macalpine-Downie, all of whom started working on the wing masts as soon as the autumn 1964.
During the winter 1964-65, designer Rodney March together with Peter Shaw built the C class Thunder II, equipped with a rigid wing mast, the first in Europe. Thunder II won the first C Class World Championship in 1965. That summer, during the Little America’s Cup’ selection, four C Class cats competed to represent England; Reg White and John Osborn succeeded in becoming the Defender on Emma Hamilton, but such a hard-won victory against the excellent performance of Thunder II’s wing mast!
In October 1965 the Cup’s Challenger was Australian Lindsay Cunnigham’s Quest II, with a wing mast that made much impression during the Australian selection trials. With much difficulty and only thanks to first-class match racing tactics did skipper Reg White manage to win the Cup 4-3 with traditional sails. This time, the wing mast had proven its worth.
During all of 1965, Austin Clarence Farrar and the Major-General Parham proceeded to test the wing sails in wind tunnels, and were subsequently able to give useful, reliable and comparative data to the British team who had just ordered a revolutionary, Rod Macalpine-Downie-design for the 1966 season. The wing (the rigid part) represented 40% of the whole sail surface. And Lady Helmsman did win the Cup in 1966, sailed by Reg White and John Osborn, against the American challenger Gamecock. The US cat was impressive with her towering 13.10-metre wing mast, compared to the 10m of Lady Helmsman’s.
The catamaran Lady Helmsman was three years ahead of her competitors, and I was lucky to be part of the shore support team in 1967 and 68. It would take four of us to carry the wing mast before and after each race, not because it weighed 70 kg, but more because the skin covering the polystyrene foam was quite fragile. Lady Helmsman remains the only catamaran to have won the Little America’s Cup three times round; the grand Lady is now showcased in Falmouth’s National Maritime Museum, in Great-Britain.
A queen : fluid mechanics
From 1967-69, things got more complicated because of the frantic developments that were taking place on three continents. Czeslaw A. Marchaj, the Polish author of the book « Aero-hydrodynamics of sailing », made a thorough mathematical analysis of aerofoils, validated by many tests in wind tunnels and hydraulic tanks. Here, at the University of Essex, with our calculations and simulations on PDP-9 and Fortran IV computers we were left behind. As for the Americans, they studied with the NASA the problems of flow around the wing mast and of its immersed counterpart (the centreboard and the rudder blade); we are often unaware of the fact that the wing mast only represents 50% of the dynamics with the remaining 50% being hidden under the water. Fluid mechanics became the thing of the day.
At the outset of 1969, British patron Robert Sanderson, the owner of Lady Helmsman retired from the competition and withdrew his boat. To defend the Cup, we were left with the 4-year-old Ocelot. The 1969 Challenger was Paul Elvström – the four-time Olympic gold medal champion- on Opus III, who won the Cup on a 4-3 victory. Hence it was the end of the English dominion over the Little Cup, losing the trophy to Denmark, then to Australia and the USA.
Meanwhile, Sailcraft Shipyard focused on B Class boats, with a new Rodney March design that was born in 1966: the Tornado. In 1967, I saw the building of two Tornados, the first one with traditional sails, and the second one a wing mast. During the 1967 IYRU/ISAF selection for the best B Class in Sheppey, the classic tornado won 5 races against 15 other B Class, while the wing sailed Tornado faced technical problems and only won two regattas. The ISAF decided to go for the traditional sail plan.