COMPUTERS played a vital part in Team New Zealand's successful challenge for the America's Cup. Silicon Graphics workstations were used to help design the Kiwis' boat, which claimed victory last weekend in one of the most famous series of sailing races in the world. Traditionally, yacht design has relied on testing scale models in water-towing tanks and wind tunnels. This is usually expensive and time-consuming, requiring new prototypes to be built for each test. But with the processing power of RISC computers, Team New Zealand was able to carry out a programme of computer simulated testing. Using the POWER Indigo2 Extreme workstation, the Kiwi team created what amounted to digital wind tunnels and towing tanks. As well as reducing the cost and work-cycle of prototype testing, the computers allowed designers to pinpoint more precisely sources of improvement and any design weaknesses in each phase of development. 'The advantage of digital [design] is that we are able to dis-aggregate the results and determine strengths and weaknesses easily,' said David Egan, the team's specialist in computational fluid dynamics. 'This has led to many insights that we would never have discovered using the old method.' Silicon Graphics workstations were used for a variety of tasks in designing the boat's hull and keel - and in deciding its weight distribution. The work was carried out using Mechanica mechanical design and optimisation software on four desktop workstations in San Diego, California. The set-up's combined computing power was 1.2 gigaflops. According to Mr Egan, this allowed him to analyse between 5,000 and 10,000 design problems in a two-month period.