Reliance's speed did not result from her radical shape alone. Beneath the highly polished skin of 3/16-inch bronze plates. the yacht was a tour de force of structural and mechanical engineering.
To lessen his boat's displacement and thus reduce the amount of water she had to shoulder aside, designer Herreshoff saved on weight until her framework looked more like that of a modern airplane than a turn-of-the-century sail-boat. The hull’s key structural members were T-shaped web frames 8 inches wide. made of 1/8-inch nickel steel and spaced 80 inches apart; at 20-inch intervals between them were flimsier L-shaped frames of 2-inch steel.
To support the tremendous weight of the mast. Herreshoff built an enormous steel keelson beneath it and added extra web frames on each side (inset. below). The yacht’s fragile skeleton was stiffened by a latticework of steel re-inforcements, including transverse braces of steel tubing within the web frames. The deck. made of 1/4-inch aluminum plates. was laid over a network of 5/16-inch steel straps, then covered with a 1/8-inch layer of cork linoleum to provide a good foothold.
ln his quest for lightweight construction Herreshoff over-looked nothing. Rather than use stock hardware. he specially designed every cleat. hook, shackle and turnbuckle. paring away pounds or ounces anywhere he could. To ensure that the spars and fittings retained sufficient strength. he tested prototypes to their destruction on three machines in his home and shop. The hallmark of Herreshoff's genius was the machinery he designed for Reliance. He introduced a foot-operated brake on the steering gear to lighten the helrnsman’s task in an hours-long race and an on-deck indicator that showed the exact angle of the rudder. The hollow rudder itself contained a true Rube Goldberg contraption: a rubber bladder that could be filled with air by a foot pump when Reliance carried a lee helm. so that -at least in theory-the added buoyancy aided the struggling helmsman; with a weather helm. the bladder was emptied and the rudder filled with sea water. And where other racing yachts trimmed their sails primarily with raw on-deck muscle. Herreshoff led halyards and sheets belowdecks through fair-leads to nine two-speed, self-releasing winches, each designed for its particular task.
With this quantum jump in yachting technology. the crew of Reliance handled her sails so neatly that other boats looked slow and sloppy by comparison. And the winches were so well designed that identical machines were used on AInerica’s Cup defenders for the next 34 years.