Paddle shape and performance

Graham Warren

Likes making paddles
I am interested in the handling characteristics of various shapes of paddles and would be very interested in any ideas/observations.

I have a straight-sided ottertail design (if I could figure out how to post an attachment, I would show the shape) which seems significantly more effective for pitch strokes that a more rounded ottertail type. I am not an engineer, and can only imagine that the straight edges give more effective ruddering, or less spillage of water.

Any comments or other observations?

Best wishes,

Graham

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The Canoe Paddle Page
http://homepages.tesco.net/~moosehead/The Canoe Paddle Page/Home.html
 
Paddle shape

There has to be a discussion or two on this topic in this site's archives somewhere, but you can also get some great info from this book:

http://merchandise.wcha.org/product_info.php?cPath=92&products_id=435
Odd, you have the same name as one of the co-authors...

Personally, I use a short, wide, well-reinforced blade in shallow water, and a long, narrow blade in deep water. The wider blade gives you more bite on the water when you can't immerse the entire blade length. The narrow, tapered entry is very quiet, which is great on still water. A narrower blade also seems lesslikely to flutter during in-water recoveries, though a blade's cross-sectional shape (& imperfections) can influence that a lot.

I suspect the straight-sided ottertail just has more blade width at the tip than your tapered-sided one, and thus would provide a bit more force at the end of the lever than the tapered blade. All else being equal, the differences in performance can be subtle. But length of the blade also would come into play, and would probably be a more significant factor.

It'll be good to hear others' opinions! :)
 
Hi Graham,
I think of voyageurs when I hear "otter tail". They used long, relativey thin paddles and kept it up for long stretches (time and distance), propelling huge loads. I'm not sure what you mean when you say, "performance". However, what comes to mind for me is how you feel at the end of day of paddling. Similar to another responder, I use a shorter, wider blade in shallow water, for mechanical function. When paddling deep water, I find a longer, narrower blade fatigues less and doesn't result in the same degree of upper body muscular pain.
As you know, total surface area varies with to blade length, width and shape. My shallow water paddle is a beavertail shape. I find that harder to control (keep steady) for straightline paddling. I don't know much about hydrodynamics, but think both pain and control of sideways movement have something to do with the distance of the centre of force from the arms/body.

Rob
 
Graham, for the pitch strokes that you are describing, think of the paddle blade as a foil, like a wing, moving through the water.

The dynamic force of the water flowing over the blade surface is what is doing the work. A long blade will behave one way, a short blade another way. A blade with an even and continuous leading edge will behave in its own way, too.

A straight sided "Voyageur" blade will present much more foil shape (and effective surface area) than a more rounded shape, where the rounding eliminates much of the foil surface at the throat and at the tip of the blade.
 
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