The next revolution in yachting?

19 May 2008

Welbourn: 'markets are wide ranging'

REVOLUTION: The brainchild of America’ s Cup designer and foil specialist Hugh Welbourn, Dynamic Stability Systems (DSS) technology is set to revolutionise yachting with its method of keeping a sailing boat upright by lifting the leeward side of the sailing boat instead of using a lead mine to hold the boat upright against the breeze.

A lifting foil, much like an airplane wing, is mounted just above the waterline when the boat is upright and projects out from the leeward side of the boat. to create lift.

The faster the DSS boat sails, the more it wants to heel, but this is countered by more lift being generated by the foil to leeward. When tacking or gybing, the foil slides through its case to the new leeward side.

When the 27ft prototype was tested by the internet sailing newsletter The Daily Sail, editor James Boyd found the boat didn't develop significant lee helm or yawing, due to the foil being a hydrodynamically efficient section.

The next question was 'is the foil a drag in light weather?' The answer was 'no, because in the light the foil is simply retracted back into the hull'. The third question – what happens if you wallop the foil on something solid?

The foil is designed to break before its case does and if this happens the yacht is still left with its keel intact, only its ‘turbo’ is incapacitated.

For this reason the creators of DSS have managed to get the insurance company Pantaneus to endorse the product.

All the data accumulated indicates a significant performance gain over not just conventional yachts but over water ballasted and canting keel yacht on almost all points of sail.

'There appears to be no particular size limitations either using the system – we have run analyses from small boats right up to 190ft and physical scale effects are very much working in favour of DSS,' said Welbourn. 'We are seeing speed increases of well over 25% when retrofitting the system on a conventional fixed keel yacht and on a DSS yacht, where the system is integral to the design, we are seeing increases of 40%+.'

Potential markets for the DSS are wide ranging. Existing race boats can be ‘turboed’ by fitting a retrofit package. Throughout its development the RORC Rating Office has been kept fully informed enabling it to be rated equitably.

New builds can benefit further from using DSS in conjunction with a hull shape optimised for use with the foil and for cruising yachts, DSS can in many cases be retrofitted in the bilge with minimal affect on the interior.

One of the greatest benefits of the system, says Welbourn, will be on Superyachts, where, finally, it represents the solution to the perennial design issue of never being able to have deep enough draft.

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