I’ve been thinking for a while how it would be possible to produce windsurfer like speeds with somthing more like a real boat. A windsurfer when planeing has the rig canted to windward with the riders weight pinning it down, so that a proportion of the riders weight is being lifted by the rig, making the whole thing effectively lighter. Im thinking that if you had a canting keel boat which also had a canting rig the keel weight could be made to end up under the center of effort of the rig, lifting its weight while it is still acting as a righting moment, thus keeping the boats hull flat for planeing. Sounds mad I know but if it works?
It’s an idea with lots of merit, I think. Some of the big Open 60 tri’s cant the rig to windward as well as rake it aft. I think that could be worked out on a model with minimum extra weight by useing the mainsheet winch to rake the mast and the canting keel winch to cant the mast. My guesstimate is about 20 degrees cant and 30 degrees rake.Problems would have to be sorted in gybing…
Rake angle is the most important ,in my opinion, because it will have the most profound effect on lifting the
boat. That I discovered accidently when originally setting up the spinnaker system used on America One and the S50:a small angle difference makes a huge diference in how the spinnaker responds to a gust. As it is now when either boat is flying a spinnaker and gets hit by a gust the bow literaly lifts. This makes it possible to carry the spinnaker dead downwind in higher wind than you can carry the main and jib alone!
I will be experimenting more with mast cant but especially mast rake downwind(on a fast boat).
You find on full size skiff type boats that more rake stops you going down a mine downwind, but you have to move your weight right back too. The problem would be doing this on a model, it would be nigh on imposible to make a canting keel to go all 4 ways. The best way would be to use your power ballast system, but with a winch to drag it back. But then you have another winch and more weight. Have you ever tried a PBS with the winches, batt and reciver all out ‘on the wire’, like a robotic crew almost?
A canting keel mono with either a very narrow hull and /or hydrofoils would probably benefit from raking the mast aft downwind not only control wise but also speed wise. Boats with less speed potential might benefit from the effects of the lift generated as shown by the spinnakers in eliminating bow burying.
Matthew, you might look on the microsail website under innovations; I think the Trapeze Power Ballast System on the Melges 24 model is shown there; it moved fore and aft as well as athwhartship. The Trapeze PBS(see the pix under monohulls on the website) on the microMOTH moves only side to side since it has a highly effective T-foil on the rudder.
PBS systems combined with rake changes are feasible if their functions are tied to something else: for instance tying the rake aft AND ballast aft to the mainsheet winch and tying the mast cant to the canting keel. Sounds complex but would work I think.
Jonathan McKee is using a canting keel system that moves side to side and fore and aft by hand-designed by Rogers. It is possible such a system could be adapted to a model-I’m looking into it for the new boat.