VIDEO: Guided tour to the AC45 wing

Wing trimmer extraordinaire, Oracle Racing's Dirk de Ridder shows us the ropes

Having been distracted by Cowes Week, Extreme Sailing Series and then the Rolex Fastnet Race, we’re now finally publishing part two of our guided tour to James Spithill’s AC45. Following Joey Newton’s lap of the new America’s Cup one design catamaran platform, so in this video wing trimmer Dirk de Ridder, who also trimmed the wing on Oracle’s 33rd America’s Cup winning trimaran USA 17, talks us through aspects of the somewhat smaller AC45 wing, as America’s Cup legends Murray Jones and Simon Daubney make a lot of noise in the background with their metal shopping trolleys.

In essence the format of the AC45 wing is the same as USA17’s in that it has two ‘elements’ with one slot. De Ridder doesn’t talk too much about the importance of the slot, other than its size, but this, like that between a conventional mainsail and genoa, is one of the vital power components of a solid wing sail as it allows high pressure air, rounding the weather side of the front element, to escape through it, encouraging the flow to remain attached further aft on the leeward side of the rear element. This is why the size of the slot increases the more camber is induced in the wing.

While the wing has two vertical elements, the front of the forward element containing the structural spar, the rear element is divided into three ‘flaps’.

In terms of controls, there are just three. The sheet, or the traveller as the Oracle team call it, determines the overall rotation of the wing relative to the boat, while the camber control determines whether the wing is I shaped (ie no camber) or < shaped (ie max camber). The flaps up the rear element are there to induce twist into the wing with up to 11degs of twist available per element, according to de Ridder.

For more wing related material, see our interview with Dirk de Ridder about USA17's wing here.

To see the video in its full screen glory, click on the bottom RH button in the viewer. And apologies - this video is 20 minutes long and takes a while to load (ie: go off and make some tea)