The super-successful Lionheart (with regatta help from the Brunel Volvo crew) is a completely new build based upon one of the family of Ranger designs drawn in 1936 by Starling Burgess and Olin Stephens but never built. Among the immediate gains over existing restored J-Class designs was the ability to put as much as 36 tonnes into that headstay…
New for old
Andre Hoek’s design studio has proved masterful at adapting and employing the most modern design tools for the benefit of classic and historical race designs
Performance through research Having invested in our first Velocity Prediction Program (VPP) in 1986, the team at Hoek Design have always placed great emphasis on performance. Initially using it to design and optimise traditional Dutch sailing yachts for racing, with lee- boards and gaff rigs, we created that first VPP on a 126KB Apple Mac computer – with the computing power of a modern calculator. To build this VPP we first had to make a mathematical model accounting for the resistance of surface-piercing leeboards, and the interaction between
these and the hull as well as the aero - dynamics of a gaff-rigged sail plan. Tank testing different hulls gave us valuable data to calibrate our ‘new’ software, and even from the early days these yachts were achieving great results. More than 300 yachts in this style have now been built to our designs and they still dominate the Dutch domestic race scene, winning the majority of races in the various classes along with many open championships. Fast forward and it was in 2005 that we first started to study J-Class design, when an existing client of ours had tried to buy, and just missed, the J-Class Endeavour, and then requested that we research the optimal and best possible design that could be built… around 70 years after the last brand new J-Class was launched. Today’s J-Class Association (JCA) was founded in 2000 to protect the interests of the class and encourage new-build yachts to enter the field. New class rules were established, the most important of these being that only existing line plans made before 1937 were allowed to be used.
A total of 22 designs were made in the original J-Class era with 10 yachts being built before World War II. Sadly, only three of these yachts survived: Endeavour, Shamrock and Velsheda.
Studying Harold Vanderbilt’s book, On the Wind’s Highway, it was immediately apparent that the longer Js were more successful than their shorter rivals. The early Js that raced in the 1930 America’s Cup had a waterline length of roughly 80ft, the second generation in 1934 were 83ft and the third generation in 1937 were 87ft, the last ones being dubbed ‘Super Js’. Taking advantage of their extended water- line length and more spacious interiors, our focus was on these longer designs for reasons of both speed potential and comfort.
As we had done in the past, we then developed a new VPP specifically for these long-keel yachts with their long overhangs. Tank test and wind tunnel data using a 20ft tank model was then used to calibrate the new software. Twelve designs were put into this software, including several
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