NUTS & BOLTS OF AN ACC 50

The basic dimensions of a 50ft ACC catamaran are: LOA 49ft 3in; Beam 27ft 9in; Wing Height 77ft; Crew 6; Wing Area 1,100 ft2; Weight 5,300lb. Hulls: Hull parameters are strictly controlled, and the hulls are therefore almost identical in appearance across the fleet. They will likely not be spending much time in the water anyway! Headsails: All built by North Sails, they are identical across the fleet. There are three sizes to choose from, depending on the conditions. Fairings: Operating in 50-plus knots of apparent wind makes windage a big deal. Daggerboards: Boards are operated via hydraulics and can be canted fore and aft to adjust the angle of attack of the lifting portions. At press time a basic L-shape appeared to be the way to go. (4A—inset)

Wingsail: The basic dimensions of the wings are set by the ACC rule, and the consist of a solid forward “element” with a trailing elements divided into three independent sections, like the flaps on an airplan wing. The key will be the control systems employed to control these different elements during maneuvers, and fine-tune camber and twist.

Grinding pedestals: The real heart of the matter: the grindgers are used to generate the hydraulic power that controls the various foils. Unseen but far more important than the grinders themselves are the electric actuators, valve, hoses and “accumulators” used to channel this energy as efficiently as possible, since there are limits to the pressure a six-man crew can generate and still sail the boat T-rudders: The other key component of the lifting equation: like the daggerboards, they are canted to adjust the angle of attack of the winglets, which are fixed on the vertical portion. Wheel: The wheels include sets of buttons that are used to cant the daggerboards and rudders, thereby adjusting the amount of lift being generated.