I own Guizmo, a minitransat located in Pto Pollenca, Mallorca, Spain.
Guizmo has some awesome features, of which the most exciting, for me at least, is its canting keel.
All sailboats heel as the wind exerts a force on the sails; without a counteracting force, sailboats would ultimately roll over and capsize. On the kind of boat that I used to sail until recently, International-14's, the skipper and crew don a harness, attach themselves to a wire coming off the mast, and hang out the side of the boat to counteract the heeling. The further they hang out, the greater their moment (literally and figuratively). Needless to say, this is a difficult way to travel long distances.
Most larger sailboats rely on a keel, essentially, an enormous piece of steel and lead that holds the boat upright. But the weight of the keel, so critical in keeping the boat upright, is a huge liability when wanting to go fast. The problem with a giant fixed keel is that, most of the time, it's not very effective, as it is not very far from the centerline of the boat. A boat with a 2m keel that's heeled 15 degrees with 1 ton of lead ballast will have the keel exerting only about 0.5 tons of force to right the boat.
Modern high-performance sailboats use a different arrangement: they rely on a relatively small keel placed on a hinge. The keel can then be canted to the side, with drastic improvement in the righting moment. In the same example above, canting the keel 60 degrees to the side will result in a righting moment of 1.7 tons. And even better, the part of the hull that remains in contact with the water can be flat, permitting the boat to skip on the surface of the water like a stone.
Of course, the keel does more than resist capsize; it's also responsible for making sure that the boat does not move sideways as it moves forward. It acts like a wing underwater to counteract sideways creep. But since it cannot do this effectively when it is canted to the side, the boat needs additional mechanisms to
stay on track. That's where the canards come in. They are lightweight, retractable wings on both sides of the boat that can be lowered to provide the sideways lift necessary to counteract creep.
Canting the keel on Guizmo is an awe-inspiring process. Inside the boat, a pulley system with 1:6 purchase goes to a winch with some huge purchase (probably 1:10), for 1:60 total force magnification. As you crank the winch and the 2 meter, 1 ton steel bulb moves up and to the side, all kinds of creaky noises come from the boat. I have not canted the keel fully to date, but I've seen it compensate fully for a 20 degree lean, which is amazing. On top of this, my body weight, stacking the heavy items to the high side, and maybe collecting some railmeat along the way and asking them to sit on the side of the boat can compensate for another 20 degrees.
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| Guizmo's keel, canards and rudders, painted in high-visibility orange paint |
All sailboats heel as the wind exerts a force on the sails; without a counteracting force, sailboats would ultimately roll over and capsize. On the kind of boat that I used to sail until recently, International-14's, the skipper and crew don a harness, attach themselves to a wire coming off the mast, and hang out the side of the boat to counteract the heeling. The further they hang out, the greater their moment (literally and figuratively). Needless to say, this is a difficult way to travel long distances.
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| Guizmo with its keel and parts of its canards |
Modern high-performance sailboats use a different arrangement: they rely on a relatively small keel placed on a hinge. The keel can then be canted to the side, with drastic improvement in the righting moment. In the same example above, canting the keel 60 degrees to the side will result in a righting moment of 1.7 tons. And even better, the part of the hull that remains in contact with the water can be flat, permitting the boat to skip on the surface of the water like a stone.
Of course, the keel does more than resist capsize; it's also responsible for making sure that the boat does not move sideways as it moves forward. It acts like a wing underwater to counteract sideways creep. But since it cannot do this effectively when it is canted to the side, the boat needs additional mechanisms to
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| Guizmo being tested for its ability to right itself up with the keel canted to the wrong side |
Canting the keel on Guizmo is an awe-inspiring process. Inside the boat, a pulley system with 1:6 purchase goes to a winch with some huge purchase (probably 1:10), for 1:60 total force magnification. As you crank the winch and the 2 meter, 1 ton steel bulb moves up and to the side, all kinds of creaky noises come from the boat. I have not canted the keel fully to date, but I've seen it compensate fully for a 20 degree lean, which is amazing. On top of this, my body weight, stacking the heavy items to the high side, and maybe collecting some railmeat along the way and asking them to sit on the side of the boat can compensate for another 20 degrees.
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