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Rudder systems

Page history last edited by Kevin 14 years, 4 months ago

Wade Tarzia:


Here are a few photos from my rudder experiments on tacking outrigger, "Short Dragon."  I wanted to try quarter rudders because they are different and I like different; also because they can be repaired at sea more easily than a stern rudder.


I first tried a vaguely Indonesian style rudder on the port quarter, held at the gunwale (lashed "permanently") and on a bearing just above the water line: a line pulled the rudder into the lower bearing and could be released as I approached shallow water. (This was inspired by looking at Tim Anderson's photos of Indonesian canoes and later afterreading Horridge's book on those canoes).  It worked well enough and was simple and cheap, but too much play on the line was irritating (hard to keep it tensioned). The photo below shows how the tiller pivots as the rudder swings up but does NOT show the line that pulls the lower rudder into the bearing, turns up over the gunwale and cleats to the aft aka on a turning pin and cam-cleat. The bolt in the lower part of the rudder is the end of an eye-bolt for that line.



Then I tried a Wharram method for hinging.  The Wharram figure-8 lashing method was one I saw first on a large Wharram catamaran at the Wooden Boat Show at Mystic, CT (where I actually talked to Wharram and Hanneke Boon without knowing who they were until later :-)  Of course I drove home at breakneak speeds to build my own.  For this I needed to build and outrigging rudder bracket and also a cheek-piece, besides some cutting down of the old quarter rudder.  This set-up worked, but I could not get the line tight enough: it had more play than my first "Indonesian" quarter rudder.  Perhaps I needed low-stretch line, or thicker line, or tougher fingers to pull it all tight, or better knots, or incantations. In any event, I abandoned this after one brisk sailing day on the coast, watching the extreme flex of the rudder+lashing-hinge.  I think it works best when the lashing surface is very long and the lashing bearing is a series of short lashings spread out (as on the stern piece of a large Wharram catamaran).  The photo below shows the ugly roughed out rudder cut down from its first version. I would later install a stopper below the pivot bolt to stop the rudder from rotating forward.  A line in the leading edge (you see the hole prepared for a stainless steel shackle) pulled the rudder into this stop, and cleated, again, to the pin and cam-cleat on the aka.


Then I kept this bracket but added canoe rudder hardware from Duckworks.  (No apologies for the bad finish work; by now I knew I would be playing with the set-up a lot, so why bother? You see I used epoxy-graphite on the bearing surfaces. I kept some lashings on as back-up.). They created agreeably precise steering, and I like them, but now I saw that the cheek-piece had too much flex (3/8 inch plywood, glassed both sides), and the rudder had too much force on the tiller (centers of pivot creating lever-arm). I need to change it again, but this time I will try a stern rudder with a steering pole and see how I like that. Right now I intend to make it a classic kick-up and probably from 1/4 or 3/16 aluminum plate.




An here is how the rudder looks when stowed for travel (the older lashed rudder):


More later after I try the stern rudder. -- WT 3/2010




Joe Creecy:


Joe was a proa_file contributor years back.  Nice rudder system:



More on Joe's rudders here:


Joe Creecy's boat




Kevin O'Neill:



This is a pretty good look at my rear rudder while sailing:



I'm sorry about the quality, this is a screen grab from video.









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