The Sails of the Americas Cup.

Ac75 mainsail. LF Herreshoff was the son of Nathanael Herreshoff and despite the famous father his designs never won an Americas Cup. This is the AC75 the class of boat that will contest the 36th Americas Cup in Auckland. Addition of foils to be allowed to lie more than 0200 m above MRP.

OUT are the semi-rigid 23 metre wings that were used on the 50 ACC catamarans IN are the new double-skinned mainsails that are now raised and lowered 26m to the top of the mast. The mainsail trimmer controls the three-dimensional shape of the mast and the mainsail. Needless to say the more power generated the more accurately both the mainsail and headsail can be trimmed.

This probably gives structural integrity to handle the mainsheet loads needed to control twist and provides a deck surface to endplate the mainsail. We dont say how the skins have to come off the back of the D-Shaped mast. It allows you to use one mainsail through every wind speed and point of sail by changing its depth and twist.

So the AC75 is potentially a little underpowered relative to its righting moment. A major change in the Americas Cup AC75 foiling monohull concept is the return to a soft mainsail but with a twist. A new evolution this Americas Cup is the twin-skin mainsail.

A concept decided on before they had finalized the AC75 hull design. Change in size of water drainage. Mast bend is the most dynamic part of mast tuning for speed.

Latest AC75 Class Rule version. 135-145sqm mainsail 90sqm jib 200sqm code zero. The most important is the position of.