The 470-class dinghy, a small, two-person monohulled racing craft, has been used in Olympic sailing competition since 1976 and, today, vacuum-infused glass fiber/polyester is the standard for hull construction. Designers of the dinghy that will be used by Marcelien De Koning and Lobke Berkhout, members of the Dutch Olympic women’s sailing team, have been looking for that competitive advantage that might bring home a gold medal at this summer’s Olympic games.
That search has been complicated by strict certification guidelines that cover everything from length of craft (4.7m/15.4 ft long), to rudder dimensions to overall boat weight, which cannot go below 120 kg/264 lb. How does a designer derive advantage in 470 construction?
For De Koning, Berkhout and resins suppler DSM Composite Resins (Schaffhausen, Switzerland) the answer was to develop a dinghy with a stronger, more stable and lighter hull than its predecessors, using the saved weight elsewhere to improve performance. Key to the improvement is a new DSM polyester resin, Synolite 8388, which offers improved laminate stiffness at less weight. The team also used DSM’s new Neogel Eco, a low-VOC gel coat that has 25 percent less styrene and weighs 15 percent less than conventional formulations. Glass content/laminate thickness in the new hull — a solid laminate throughout — varies with location, with minimum thickness of 1.5 mm/0.6 inch amidship.
DSM’s technology increases the rigidity of the boat by 120 percent, makes it 200 percent stronger and reduces the weight of the composite by 2.5 percent. The added stiffness is expected to minimize energy loss from wave impact and, therefore, optimize speed. The reduced weight will permit the use of more ballast low in the hull to minimize swinging — the tendency to change directions in choppy waters, which could prove decisive in the short waves that are common off the Chinese coastal waters in which the 2008 Olympic sailing competition will take place.
“The new Olympic boat offers the best of two worlds: a perfectly molded shape with exactly the right stiffness, which can bring speed benefits,” says De Koning. “This combination was previously not available. We are very glad we have the opportunity to sail this boat." Look for a final verdict on the design in August off the coast of China.
For DSM product information, visit www.compositesworld.com/showroom/1314.