Opposite: Intrepid was good but perhaps Olin Stephens’ follow-up Cup defender Courageous was even better? The first aluminium 12 Metre defended the Cup in 1974 then came back three years later, now in the colourful hands of Ted Turner, to win again. A further three years later she was still fast enough that, had she made it into the 1980 Match, plenty of 12 Metre aficionados believe that she could have seen off Alan Bond’s Challenger Australia – though less comprehensively than Dennis Conner’s first mighty ‘no excuse to lose’ campaign did with Freedom. How good was she…? At the 2021 12 Metre North Americans Courageous won five out of six races. Above: among S&S’s most loyal clients was British PM Edward Heath (second right) – seen with his crew having just won the 1969 Sydney Hobart Race on the little S&S 34 Morning Cloud. Seahorse founder and Heath’s regular navigator Anthony Churchill is far left
challenger Sceptre. Columbia’s closer rival that summer was the 12 Metre Vim, drawn by Olin for Harold Vanderbilt around the time of the Ranger defence in 1937. S&S were not given the opportunity to
produce a new design for the 1962 defence and the Americans came uncomfortably close to losing the Cup against Australia’s lovely Alan Payne design Gretel, but for the 1964 defence Olin and his Madison Avenue team were back with Constellation, which first defeated the Bill Luders-designed American Eagle in the defence trials and then defeated a marginally better British challenger, Sovereign, in the Cup Match. For the 1967 defence Olin penned
arguably one of his greatest designs, Intrepid. Like Dorade, in 1931, Intrepid was a revolutionary interpretation of a par- ticular set of measurement rules. The gradual shift of art into science, a develop- ment that Olin was a great proponent of, was expressed perfectly with Intrepid. First you have the inspiration to try something different – albeit based on logic and experi- ence – then you apply the science of the day (tank testing in this era) to develop the ‘art’. I well remember a philosophical conver-
sation with Olin, some 10 years later, when he was in the thick of trying to keep International Offshore Rule development under control, where he theorised about the possibility of a perfect mathematical solution to the art of hull shape. He mused
about sets of numbers one day creating shapes with the least resistance – a portent indeed of today’s computer-generated fluid dynamics, but tempered by the knowledge that the sea and the wind give highly variable and multiple playing fields, further complicated by measurement rules and other random factors that demand such unscientific applications like intuition as the starting point to a fast hull shape. It was honing this intuition that had fasci- nated Olin from his early boyhood days… the relationship between lines and speed. But science was to take something of a
step backwards when Olin wanted to further develop the Intrepid concept with 1970 defence candidate Valiant. The science of the tank became the unwilling partner of a mistake in intuitive, logical thinking. Olin had proved with Intrepid that the
bustle was a huge success. Metre boat rules demand a certain displacement within a given length and beam; this displacement requirement produces deep and full midship sections. The bustle, helping to give more displacement aft, allowed for some of the volume to be taken out of the midship sec- tions producing a potentially faster shape. Olin also wanted to make the keel sub-
stantially smaller to reduce wetted surface, but this further reduced volume and hence displacement which had to be put back somewhere. The bustle, which effectively
extended the underwater lines aft, also took care of the lost volume from the smaller keel. With the Intrepid design this redistribu-
tion of displacement was fairly subtle, but devastatingly effective. It seemed logical with Valiant to take this concept of volume redistribution and small keel to even greater lengths – an evolution supported by the scientific data from tank testing. But it was flawed science, and the on-the-water performance of Valiant failed to live up to the performance prediction of the small- scale model in the towing tank. The Valiant experience was a salutary
lesson for Olin Stephens. You could take a successful idea and push it too far. The brand new Valiant had not only been beaten by Intrepid, albeit now modified by another designer, but had also failed to show the expected performance gains from the 1958 Weatherly design which was being used as a trial horse. Valiant’s humbling lack of performance
caused a complete re-evaluation of the science of tank testing. The relatively small models used at the time were blamed for the poor data that persuaded Olin to push the lines of Valiant to the extreme. Olin’s follow-up, 12 Metre Courageous for the 1974 defence, was a much more conserva- tive evolution of the original Intrepid design and went on to defend the Cup easily that year and again in 1977.
SEAHORSE 47
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