The double-sail skins combine with the spar to form a wing generating the power the AC75 needs to foil.

Ac75 mainsail. AC75 Cockpit Layouts Mainsail Differences All four AC75s have a central beam running the length of the cockpit. We caught up with Emirates Team New Zealand embedded sail designer Burns Fallow to learn more about the twin skin mainsail. Now we have an independent leeward skin of the mainsail which is the most important side to get right.

This has the effect of creating a. This is the AC75 the class of boat that will contest the 36th Americas Cup in Auckland. It allows you to use one mainsail through every wind speed and point of sail by changing its depth and twist.

Underwater is where things get really interesting this Americas Cup but the story starts inside the boat. We dont say how the skins have to come off the back of the D-Shaped mast. The double-skinned mainsail that has hit superstardom thanks to the AC75 is a surprising rediscovery of a patent developed by LF Herreshoff in 1929.

LF Herreshoff was the son of Nathanael Herreshoff and despite the famous father his designs never won an Americas Cup. The Sails of the Americas Cup. A new evolution this Americas Cup is the twin-skin mainsail.

Latest AC75 Class Rule version. The most important is the position of. A major change in the Americas Cup AC75 foiling monohull concept is the return to a soft mainsail but with a twist.

The mainsail trimmer controls the three-dimensional shape of the mast and the mainsail. Mast bend is the most dynamic part of mast tuning for speed. Ive been told that the mainsail is small enough that in most conditions the gennaker or more correctly the Code 0 will be needed to provide enough power for foiling.