Rudder Spacing From Hull ??

This is the coolest thing I have heard of in ages. 1200 hp lobster boat races. Its got me thinking, if I could fit some big tabs and 3 or 4 blown big blocks to my 35 ft canoe stern ketch I may just get into the thirties without a spinaker. Can't let You Americans have all the fun.

 

What does built down hull mean?.

 

The wedge is out, we will be using a plate rudder. That should help simplify things.

So from the original question, The answer seems to be keep the top as close to the bottom of the boat as possible.


Looking at the design of the proposed rudder, does anyone have any suggestions and why. Such as angles and shape.

 

With a flat plate rudder shaped like the one in post #8, it can't make much difference how close to the hull the top edge is. The mounting shaft hardware kills the effectiveness near top and bottom anyway.

Maybe the best bet is to look at something different that could improve the steering effort versus rudder area. If a plate fence were welded to both top and bottom and the shafts attached outside of the plates, there would be no interference from the shaft over the rudder surface. Fences would also reduce tip vortexes and allow a smaller rudder.

Has anyone tried something like that?

Restriction to a plate rudder makes all the shaping irrelevant although the leading edge should be rounded.

 

Unglaublich wie tief.

pogo

 

Twin, higher aspect rudders, spaced just outside the prop's diameter can dramatically improve steering efficiency at these speeds. They'll offer some improved vectored thrust in the turns, which will kick the single rudder equipped boat's butts, when the helm is cranked. There's some additional drag associated with this setup, but given the total drag equation on these hulls, not a big element overall. Turning is winning on these puppies.

 

Paul, Its not clear to me but there may be some rules that we are not aware of that restricts some "improvements" on these boats for this competition.

Would be good if the OP clears that up.

 

Rules?? Lol

Nope, not here.