Some of my gear - Rudders (From my old website) sails electric pumps
The cheeks are approx 7" (18cm) high, and approx 3 3/4" (9.5cm) wide, and with the gap between them to take a blade 3/8" (9mm) thick. The blade is about 19" (48cm) long and 4' (10cm) wide. It is shaped like a double sided aeroplane wing, with the 'blunt' end to the front, then gradually tapering off to a sharp edge at the back.
A few important notes to improve its reliable
The cheeks should be higher than the circular part of the blade. If it is not, and the up/down cord gets a bit slack, the cord may fall sideways off the top of the blade (the top of the blade is grooved with a round file). Make sure the blade is a neat fit within the cheeks, so the cord can't drop down between the blade and the cheeks, and jam.
To attach the up/down cord I drill two small holes in the edge of the blade about half an inch long (12mm), then drill into the end of these holes at right angles (from the side of the blade). I countersink these holes, then I feed a piece of nylon cord through the holes. Then melt, or tie a knot, or splay the end of the cord and araldite it in place, in the countersunk part - so it wont pull out.
The triangular piece has holes at its extremities to take the 'steering' wires (attached with small shackles), and a small nylon fitting for the up/down cord to run through. This nylon fitting is exactly over the top of the rudder pin (which is put in from the top) - so that the pin can never fall out, even in a capsize. The pin does not rely on nuts or split-pins to hold it in place, these invariably disappear at inopportune moments, and leave the rudder dangling in the water. The nylon fitting can be on top, or underneath, the triangular piece.
You will notice on the Greenlander above, that the bottom of the cheeks are cut off at an angle to line up with the line of the hull. This is so that when you are seal launching down rocks, you will slide off smoothly - and not come down heavily on the rudder cheeks if they were left sticking out horizontally.
You may well hear that people have fitted 'Tasmanian' type sails but had to modify them so as to be able to paddle. Obviously these people only think they have fitted Tasmanian sails and fittings - because I have been using these for over 20 years, and they in no way interfere with your paddling. In fact this reminds me of a paddler who came to Fiji with us in 1984. He had borrowed a Tasmanian fitted kayak from a friend in Sydney, and religiously copied everything to fit to his own sea kayak. When we got to Fiji I was looking at his kayak for the first time, and asked him why he had omitted a small nylon fitting on the rudder that the up/down cords go through. He said he couldn't see that it did anything so omitted it. I suggested he go out on the water and turn his rudder 10 or 15 degrees, and then raise and lower his rudder. He did this, and then returned to shore, saying he could now see why that nylon fitting was necessary. His cord had dropped off the side of his rudder blade.
We have spent over 20 years designing and using a lot of the gear we use in Tasmania, but we still get people who make a half-hearted copy, and redesign all the faults back into the gear that we have spent so much time in getting rid of. I recently saw a website in the USA which claim the steering wires on the rudder will eventually break because of the constant bending. This was the first fault we designed out of rudders, but it seems the yanks have now designed it back in again.
In case you are wondering how it came to the attention of the rest of the world, it was like this. There was a chap paddling round Australia many years ago, in a kayak that I personally don't have much time for. He went from Melbourne to Brisbane, and then a member of the club got an urgent phone call - "Make me a rudder and send it up pronto." This kayak eventually found its way to England where a large well known canoeing company copied the rudder.
Incidentally, the way I test the effectiveness of a rudder is
it hard over one way, and then use sweep strokes on the other side to
and counteract the rudder. If the rudder is more effective than the
strokes, then it is adequate.
This page last updated February 12, 2001.