BOR 90 adds an innovation - a wing mast replaces the standard 'soft' main.
Watch (one of several):
http://www.youtube.com/watch?v=_KyVm8ilcxURead:
http://bmworacleracing.com/en/yacht/index.htmlFrom the website:
Notes on the wing:
The wing sail consists of two main components: the main element and the flap element. The main element is one single piece that rotates around the mast step. Eight individual flaps rotate around the trailing edge of the main element. Both elements are separated by a small gap and linked together by nine main hinges.
The wing is primarily constructed from carbon fibre and kevlar with a light, shrinkable aeronautical film material used as an overall skin over the frame. Nearly 40,000 man-hours of construction went into building it.
According to Joseph Ozanne, an aeronautical specialist with the BMW ORACLE Racing design team, the ability to trim the wing easily is one of its big advantages over a soft sail.
With a soft sail, it's so big, it's difficult to shape as you only have control over three points (head, tack, clew). You need massive tension to trim the soft sail,” he says. “With a wing sail, you can get the shape you want much more easily.”
The main trim parameters are: master wing rotation (similar to mast rotation on a conventional rig); master camber control (general rotation of the flap element); flap twist control (each flap can have a specific angle of rotation).
“On paper, it's a clear advantage over the soft sail,” Ozanne says. “It’s on such a different scale to what has been done before, it's hard not to have some uncertainty. But we are more and more confident... I think it's going to be a strong addition for us.”
