Karlis K wrote:2:05 - 2:09, a whole 4 seconds of Easy Go action if anyone is in a hurry.  I spent a whole evening a few months ago watching all the "tellie-port" videos, great stuff.  Nice yuloh Bob, do you increase thickness as you taper the width? My shaft is a 2x4 after the 4.5' blade, and it seems a little floppy at the moment. 

Arne Kverneland wrote:

I haven’t tried it but I suspect that the fish-tail sculling technique, (where the same edge of the blade is always the leading edge) is a more high-gear version, better suited for prams and dinghies. This requires a different oar design. Again a slightly raised pivot position would probably help. That would be fun to try!

Cheers, Arne

Stavanger, Tuesday

I found that the position of the upper end of Johanna’s yuloh, at shoulder height, felt very right. In fact everything felt right except that I got too little resistance when sculling unless I used excessive pitch. I bet a bigger blade would have helped.

I never felt any need for adding weight to the blade-end of my yuloh. My idiot-proof pivot kept the oar secure at all times and when I was to start sculling with the blade floating, I just needed a couple of fast high-pitch strokes to get the blade down in position and the lanyard taut.

That Japanese ro with the handle on the upper side no doubt has the bend cleverly tuned so that only a light force on its handle is needed to vary the pitch. On my test yuloh, the pitch mostly depended on where my right hand gripped the handle ("the wrench"). If I grabbed it close to the loom, there was little pitch. If I grabbed it close to the lanyard or by the lanyard itself, I got more pitch.

The Eastern yuloh with its falling-leaf kind of sculling no doubt is a low-gear propulsion device; very good when the manpower to displacement ratio is low, but not fast. In the other end of that scale one finds the 6- or 8-oared gigs (in UK) where all that man-power and long waterline with moderate weight resulted in impressive speeds.

I haven’t tried it but I suspect that the fish-tail sculling technique, (where the same edge of the blade is always the leading edge) is a more high-gear version, better suited for prams and dinghies. This requires a different oar design. Again a slightly raised pivot position would probably help. That would be fun to try!

Cheers, Arne

David Tyler wrote: Arne,

Your pivot point on the pushpit makes sense to me. The illustrations of passenger carrying sampans show a built up structure on the stern for the yuloh pivot.

 My attempt at a yuloh on my 9ft dinghy didn't work very well either, because it immediately became clear that the pivot needed to be much higher above the waterline than the top of the transom. I, too, lost interest.

And my oars never fail, and are more powerful than a yuloh - just like your Yamaha.

Hi David

Your point about the need for the pivot to be quite hige above the water line is well made. I tried to cover this point by suggesting that the yuloh was designed seperately and clear of the stern of the boat and them the drawing moved forward onto the boat rather than designed to fit the existing transom. I think few experimenters realise the need for the higher point to get the necessary mechanical advantage. This may help explain the high stern to be found on many Chinese boats and sampans.

Your oars never fail, but if you were trying to row the parent craft then the oars might not be more powerful, nor less tiring.

Cheers,  Slieve