sharpii2
Senior Member
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- May 31, 2004
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I don't completely understand what your goals are.
Are they to get the mast off the cross beam? End up with a giant jib?
Or something else?
IIRC, a Tornado has a 3/4 fractional sloop rig. Such imposes very little stress on the hull structure for its performance capability. The main issue is holding the mast upright and maintaining adequate tension on the jib luff.
With an 'A' frame mast, you can have a clean luff on the main as well as the jib and, perhaps get better performance. But the long main luff needs to be to be held tight as well as the jib (with much greater tension, due to its longer length). This may end up putting more stress on hull structure rather than less, even with the elimination of shrouds.
A compromise would be to put ladder rung like spreaders between the two legs and run a much narrower spar up across them, between the two legs.
To this, the mainsail could be attached.
Now you have eliminated the long, unsupported, main luff and replaced it with a spar with a much smaller cross section than the original mast. This might provide some performance improvement at the expense of greater top hamper.
A third approach is to go with a tripod mast, with the main, sail carrying portion, running up from the very bow and canting aft so the mast head is even with the transoms of the boat. Two shorter legs come up from each side of the boat to meet the main leg somewhere near its mid point.
To the long center leg, the roller furling sail is attached. Viewed from the side, this looks like a very tall lateen sail.
Now you have eliminated the very tall 'A' frame, the spreaders, the narrow spar between them, and the jib stay. You have replaced them with a thicker spar in front of the sail, giving up some performance, but have reduced top hamper and have all but eliminated sailing stresses on the cross beams.
Now you have a single sail, which may make up for some of the loss of efficiency.
The biggest advantage of this rig will be raising it. A block and tackle could be placed at the apex of the two shorter legs to raise the longer center one. These two shorter legs could be set up to pivot fore and aft. Pulling on the block and tackle will cause the two shorter legs to pivot upward and raise the long center leg as well.
This would be a revelation in simplicity compared to raising the more conventional rig. It could be done safely even in a strong cross wind.
Most likely, a more conventionally rigged Tornado will beat you in any kind of a race, though.
I don't think what Brian did would work with your boat. Going with the bipod mast eliminated the need for heavy shrouds very long spreaders, not to mention the downward loads they would put on the wing deck. But he still has back stays and back spreaders to hold the jib mainsail luff tight. No doubt, the wing deck and hulls were designed and built in anticipation of the loads these would impose. Not so with your boat.
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