Delta wing sail trimaran

Following up an interesting discussion on the America’s cup thread, regarding the benefits of maximising leech perpendicular to the air flow, I thought that I would try to combine the delta rig and wing sail concepts. I’ve built such a sail for my small trimaran:

I’ve got no idea how this is likely to perform. Anyone willing to speculate?[/LEFT]

Hi Jim
How did you get that twist in the front section?
Lots of camber at the top?

At light winds the wing will fall back at the centerline of the hull because the wing is not balanced like an iom- jib.
Use as a counterweight a soft jib, mounted at a beam as seen at the swing rigs :wink:

forget about the jib. That wasn’t me, must have been my android - perhaps because of those strange moves at the currents of murray river :stuck_out_tongue:

well no more jokes - I try :wink:

That jib at a beam attached at the front section should turn the back of the front section windwards, at least a camber out of control.

With that rake and the weight of your wing it should fall back at the centerline of the hull at light winds.
With a soft main with that rake I use more camber and more twist at light winds.
Or I use a greater rig. I could reduce the rake, but then I should adjust the sheeting and the stays.

Hello Wolfgang,

I’ll ignore the questions from your android (here is a clip of some more disturbing moves from the Murray).

If you haven’t seen Claudio and Marc’s work with the Delta rig it is worth a look.

I’m not quite sure what you mean when you say "That jib at a beam attached at the front section should turn the back of the front section windwards, at least a camber out of control. ", could explain?

Regarding the balance of the sail, I take your point. I have moved the pivot point back to approximately the middle of the main element, and I’ve added a tube to allow a counter weight to be added:


Oh no, not again :cool:

Riversailing in those currents is strange :rolleyes:

As an android-newbe I am struggling with my android all the time, too much funny things coming out.
But I’ll get control about it, at least with my new camera app, no more single-handed sailing and videotaping :wink:

This delta rig reminds me to a mc-rig. Someone in the german RG-65 forum reportet, that the mc-rig is performing very well at a downwind course, when the swing-rigs are starting submarining. Should be the same with the delta rig?

You don’t want too much weight at your multihull, especially above the bow.
Some time ago my thought was, don’t use lead to balance the wing, set a small jib at the tube with that weight needed. You could balance the wing with this jib, but when wind comes up, you can’t predict what’s happening next. Will that jib produce some desired lift or will it turn the front section leewards so you get at flat camber or even an upside down or windward camber?

… was there a wakeboarder :confused:

There was a wake boarder, but fortunately there were no collisions or damage.

The camera attachment on your rc controller is a great idea.

Unlike the Delta Rig, this sail doesn’t look to be very promising in light winds. As Wolfgang suggested the wing wants to fall back to the centre line:


There were moments when the wind picked up where it started to look a bit more interesting, so I’m still interested to see how it goes in a stronger breeze.

One nice feature is the simplicity of construction. Unlike conventional wings there is not rotating mast. I’m tempted to see if this arrangement can be used with a normal wing shape, perhaps on a larger boat.