Keel for CHALLENGE XII (KA-10)
Designer
Ben Lexcen
(1936 - 1988)
Datec 1980
Object numberANMS1543[354]
NamePlan
MediumFilm copy
DimensionsOverall: 710 x 530
Copyright© Ben Lexcen
ClassificationsMaps, charts and plans
Credit LineAustralian National Maritime Museum Collection purchased with USA Bicentennial Gift funds
DescriptionA Ben Lexcen ‘lines plan’ section view of the lead ballast keel used on CHALLENGE XII (KA-10) a 12 metre yacht commissioned by Alan Bond as a possible challenge boat for the 1983 America’s Cup race. The drawing has been taken from the ‘overall hull lines plan’ of CHALLENGE XII’ marked ‘Drawing No. 1284M’ drawn in April 1982. CHALLENGE XII proved to be a fast yacht, much- liked by the Australian crew, but later sold to the ‘Challenge 12 Syndicate’ in 1983 when AUSTRALIA II (KA-6) was chosen.HistoryAlan Bond’s quest to win the coveted America Cup for Australia began in 1974 when he hired Ben Lexcen (then Bob Miller) to design SOUTHERN CROSS (KA-4). The 1974 challenge was not successful, but they went on to design and build AUSTRALIA (K-5) for the 1977 and 1980 races. At this time, Lexcen teamed up Johan Valentijn, a young but experienced Dutch naval architect, who had worked for ‘Sparkman & Stephens’ in the US. They worked together as a partnership on a number of yachts including the 45-foot IOR yacht GUIA V in 1976 for experienced Italian racing yachtsman Giorgio Falck. The two designers spent seven months in 1976 testing 1/9th scale models of AUSTRALIA at the University of Delft test tank in the Netherlands. This period of on-site design and tank testing scaled models in the water, proved vital for later design work on AUSTRALIA II (KA-6).
The 1977 and 1980 challenges of AUSTRALIA proved unsuccessful, but were a considerable help in the future design and build of the winning yacht AUSTRALIA II. Remarkably, in 1981 Alan Bond, and the Australian syndicate, commissioned Lexcen to design two 12 metre yachts for the 1983 challenge. He designed both AUSTRALIA II and the heavier CHALLENGE XII (KA-10). Both were built by ‘Steve E. Ward & Co.’ boatyard in Perth, Western Australia and launched in 1982.
Deciding to use the lighter, more revolutionary designed AUSTRALIA II for the race CHALLENGE XII was sold to the ‘Challenge 12 Syndicate’ in 1983 and shipped to Newport, Rhode Island in the US for the challenge trials. The displaced weight of CHALLENGE 12 was significantly more than AUSTRALIA II, had a larger ‘bustle’ aft and more volume in the forefoot. The ballast keel was conventional in plan-view but sported a bulbous shape in section view, lowering the centre of gravity.
CHALLENGE 12 was not successful in the trial races at Newport RI in 1983 but despite this, the yacht was later used by several other challenge syndicates in France and Italy. In 1996 CHALLENGE 12 underwent an extensive three-year refit and raced again at the St. Tropez Rolex Cup in 1999. Purchased by Jack LeFort in 2017 the yacht returned to Newport, Rhode Island and in 2019 and won the Modern Division of the 2019 12 metre World Championships help at Newport.
SignificanceRemarkably, in 1981 Alan Bond, chief executive officer of the Australian challenge syndicate, commissioned Ben Lexcen to design two 12 metre boats for the 1983 challenge. Both yachts were built by by ‘Steve E. Ward & Co.’ at Cottesloe near Perth, in Western Australia. The ballast keels for both yachts were cast at the Western Australia ‘State Engineering Works’. The first, and more conventional designed yacht, CHALLENGE XII (KA-10) was launched in 1982 and trial sailed by the Australian challenger crew. It proved to be a fast, if not standard yacht, which the Australian crew were keen to use. During a visit to the Dutch water tank testing facility at Wageningen in mid-summer 1981, Alan Bond, together with John Bertrand, the captain chosen for the 1983, were surprised to see the undeniable results of the tanks test and computer analysis of Lexcen’s AUSTRALIA II. These tests indicated his new yacht and keel design would be 5% better to windward than other similar 12mR conventional designed yachts. Alan Bond decided to use the lighter, more radical designed, AUSTRALIA II (KA-6).
