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... with a broken arm

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Comment by Hans Hammig on March 23, 2011 at 1:35pm

I have always wondered why there are so many rudder damages. Clearly the basic rudder designs disregard simple engineering principles. So my rudders will not have a tiller. The steering cables (Dineema) will control the rudders in their center. The cables go under the bimini seat and you steer with a dinghy style handle (with two fingers, they say). Basically the wooden quadrant is integrated into the rudder, which is lashed to the hull.

The system should be almost friction free. For bad weather steering, especially on engine return trips to harbor, it can be connected to the pilot house steering wheel.

Comment by kim whitmyre on March 23, 2011 at 2:50pm
Luis, do you know the species of wood involved?  I have often thought of making lighter tiller arms, as mine are white oak. . .Quite strong, but heavy. I remember coming in one day with rooster tails coming off the rudders: the force required to maintain course was quite large!  It was time to reef, but I was almost in the inner harbor where the wind dies.
Comment by Hans Hammig on March 23, 2011 at 3:41pm

Kim's comment makes me cry.Rule # 1: A modern catamaran (steered with two fingers) should never have too heavy a rudder. Trim your sails. Trim until the boat sails straight without touching the steering system. In a seaway, try to get as close as you can. Rule # 2: The sails generate much more power than anything else on your boat. Manage that power correctly, and sailing is a joy. Try to overpower it, and you will brake a great deal of furniture. Try it out with little wind. Lash your tiller and try to steer only by trimming your sails. Great fun. Great security cushion in an emergency. I was once caught in a vicious ventury between Greek Islands and although I had hydraulic steering the yacht would run out over the rudder. Until the besan was released, that is. It was dark as usual, and conditions were really bad. Even after the release, conditions were still confused, but the boat (47 foot cutter style ketch), with the center of effort restored to reasonable proportions, was well under control.

And then the tiller at the far end of the rudder, while the great force is down in the water. People break rudders, tillers and quadrants for ever. Why not put the controls into the center of the forces. Halfway down the rudder?

Oak or not oak, Luis' tiller looks a bit anemic, you can see it will not take any punishment.

Remember. We must not fight the ocean. We have the opportunity to use the forces, the energy created by nature. We just have to channel it in the right direction. To our benefit. Amen.

Comment by Hans Hammig on March 23, 2011 at 3:49pm
Murky water. Rio De La Plate?
Comment by luis on March 23, 2011 at 4:05pm

hi kim,

don't exactly know, maybe bertrand can help because he know the builder; but it seems to be what in my country is pine. the breaking occurred due to a mistake to the helmsman (me, who am a mortal being and do lot of errors). we were arriving to the mooring (mud in river bed) and aground dur to low tide. then, i reversed and at the same time turning; rudders ran aground in the mud (i didn't realize this) and then one rudder teist4ed more than the other and crack! :-(


Comment by Hans Hammig on March 23, 2011 at 4:36pm
Just what I said. Such an incident will not break your rudders, if correctly engineered. It will just wrench the controls out of your hands. By the way, most rudders are broken when reversing.


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