Clockwise from top left: using the resources of parent company Holland Composites, the platform of the DNA F-1 was designed using CFD to achieve low drag while also feeding clean airflow onto the bottom of the rig (see here F1 front winglets); this early DeckSweeper presented some interesting tacking challenges; tip vortexes are horrid!; big pressure difference either side of the rig with a good seal – at deck level the difference would be small to negligible using a conventional boom; rudder stock detail – curved carbon tillers stay out of the airstream plus triple foil clamps to prevent movement; high speed work of art… yours new for €22,000
With my early DeckSweeper I was still using a normal mesh trampoline which was still leaking air and therefore provid- ing less pressure. Incorporating the trampoline into the system would now be necessary to gain the full benefit of the concept. Even better, a carefully shaped deck offered further advantages, identified in VPP models that Mikko Brummer of WB Sails carried out for us.
The improved deck/rig seal drastically improved the pressure difference in the lower part of the sail, improving effective sail area by around 5% while lowering the centre of effort in the sail by a good 60cm
and reducing heeling force accordingly. The next step was to customise the deck itself, where we found that with good design we could decrease vortex losses at the foot of the sail, reducing drag while allowing us to add back camber low down to get more driving force right where you want it.
With the design of the latest DNA-F1 A-Class we integrated all these elements into a homogenous platform optimising the airflow wherever possible and reducing drag. Of course, the rules of the A-Class do limit sail area, so to lengthen the body of the sail to reach the deck I had to remove
area from the top. But rather than being a compromise, this in fact offered another area of improvement since less area high up also means less drag there.
What now became more critical than previously, however, was to ensure the correct sail twist and Contender’s Maxx sailcloth proved a big help here in giving us stable twist with the shorter chord high up. The A-Class continues to challenge me to the maximum as an engineer and as a sailor. Being able to combine the two is for me the ultimate pleasure. Winning the worlds this year with my own sails makes me a proud man.
SEAHORSE 55
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