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Wing Nuts


Wing Nuts

If you ever doubted the America’s Cup’s ability to drive interest in sailing, today’s frenetic amount of activity in the AC forum and new interest in the C-Class Cats should convince you otherwise.  One anarchist claims that the photos we showed you yesterday are actually a head-fake; that they’re just aluminium sheeting used to extend the frame of the BMW/Oracle assembly tent to accommodate the actual wing, which could be leaving Anacortes unobserved as we speak.  Whether the wing is already in San Diego or hidden somewhere else we do not know, but we figured this would be a good time to give you a primer on the parts of a hard sail, with big thanks to our good pal ‘blunted,’ the current Little America’s Cup defending crew.

Funny how everybody seems to like wing things all of a sudden.

Terminology: We call our front section on our wings number one and number two. as that foil is made of two pieces, the trailing edge being a flap. Behind that we have #3, which is a discreet flap unto itself. We also call it and think of it as a leech.

Our wings also have an internal tube spar, which we call…the spar. In our wing it is the primary structure holding everything up there.

Ribs, well yup, they are ribs.

We have hard bits and soft bits. Carbon or shrink film, tape and dyneema, thats what she’s made of.

We have a hounds bulk head and a boom box, which contains structure and control systems. Inside the boom box we also find the rotator arm which controls the #1 twist. We also have a leading edge fairing on #1.

This is all related to the Alpha, Orion, Rocker, Cogito style rig /wing.

In the basement I have a simpler rig under construction for me and my kids to play with. It simply has a main element (The leading edge foil section) and a flap. It’s dead simple. You adjust camber, and sheet angle, thats it. It will not be great at deep angles but its simple and should tear around on a reach nicely.

On the Alpha wing, we can adjust Leading edge twist (Only use that downhill to deal with gradient), Camber between the #1/#2 and #3 sections, and twist in number 3 (Delta control) and of course sheet which is angle of attack. Slot control is acheived by little fixed fingers called idlers, they affect the distance between the LE of #3 and the TE of #2, which in turn affects the extent to which #2 articulates. My little model wing will only have sheet and camber, no twist in either section unless it blows in and twists the foils, the model wing is simply shaped pink foam with a layer of carbon bagged on top and a bit of structure will be cut into it here and there.

The arms that stick out of our wing aloft, at the hounds, are called the yoke, they attach to the delta lines.

We call the top of the rig the tip.

So I guess we’ll see soon enough what all those bits in SD add up to, and then someone can put some nomenclature to that when it appears.

Recap: #1, #2,#3, Camber, front twist, Delta, sheet, Idlers. It’s all you need to know, well — for a C-cat anyhow.