with the center ridge on one side of the blade?
It’s not a GP at all
Sounds like an Aleutian Island style paddle.
The one with the ridge is an Aleutian style, based on the region where the paddles were often used. GP means Greenland Paddle, and is based on the paddles used traditionally in Greenland.
Thanks. I knew I was wrong but also
knew I would get the correct answer.
Aleut, GP, symmetry, dihedral
You are probably talking about an Aleut paddle as has been pointed out. That said, some Greenland paddles also feature a pronounced diamond shape on both paddle faces that results in a sharp peak down the center (on both sides of the blade).
Just as an aside, Greenland blades are not always completely symmetrical. There are East Greenland paddles (among others) that have “bent blades” (dihedral). In other words if you place the loom on the ground with the bent blades rising upwards, the tips of the blades will be an inch or so above the ground. Early researchers thought the paddles had warped, but now it seems pretty clear they were deliberately carved that way.
These are pretty cool to use. I started my Newfoundland circumnavigation with one, (but that paddle was destroyed by a huge Newfoundland dog – a bizarre story in itself). BTW, I orient the blades with the bent side facing forward (as per a bent-shaft canoe paddle).
Aleut and a joy!
I researched this well before building my own Aleut paddle out of Western Red Cedar. This paddle is a joy to use, easy on my body, very efficient (particularly in any wind), great for distance, and can do anything you need it to do well. It’s also a conversation starter everywhere!
I love my GP
I purchased a Greenland Paddle last winter and it has been a true joy. Mine is a Lumpy. Very nice workmanship. Fits me like a glove.
the Aleutian Solution
is working for me!
have two, both made by Tom Froese of tandjpaddles.
Like them a lot. For me they translate to quicker acceleration, longer cruising, and more bite in the waves. I use greenland paddles too, and Euro blades. They all bring something different to the game.
Agree w. greg stamer than the ribbed side makes a fine powerface, bifurcating the water and making the stroke smooth and efficient. Almost impossible to create flutter w. an Aleutian. And the flat side works just like a traditional greenland paddle.
And yeah, they are conversation starters.
If it’s made out of wood
I call it a stick. I build my own, but I haven’t built one yet that gets used as much as my Euros.
Wow, very interesting. Questions.
Live and learn on pnet. I had never heard of or seen such a paddle before.
What is the purpose of that sharp ridge, and why and when would you use the ridged side vs. the smooth side?
I Asked That Very Question
in a thread a while back. The answer I got was that the ridge prevented flutter. Since my GPs don’t flutter it’s not the paddle for me.
I was making wood chips before
I started paddling and I think they look cool, so …
What is the power face?
If the ridged side is supposed to be the power face, that sharp ridge seems to be a rather primitive and overly aggressive means of preventing flutter via what we (somewhat confusingly) today call camber or dihedral. My first assumption was that the ridged side was the back face.
The ridge must degrade slicing and feathering the blade, and also must have some effect on rolling.
The function of the ridge is to anchor the stagnation line on the paddle face, or at least keep it from wandering too far. Flutter can be interpreted as oscillation of the stagnation line, causing flow to preferentially spill over one side of the blade, then the other, in rapid succession. The resulting pressure fluctuations on the blade cause the paddle to wobble side to side.
A GP held in a canted manner will generally present enough asymmetry to the flow to anchor the stagnation line in the right place, so a canted GP shouldn’t flutter, unless pulled way too hard. An Aleut paddle can be used with the smooth face as the power face in the same way.
It’s the flutter thing.
That’s the purpose of the ridge and it works well to stop any flutter, which can be a problem if you don’t cant a GP.
You should trust the Aleuts and the Inuit on anything with a kayak. They were sophisticated in their technologies for their intended uses, and this wasn’t entertainment to them, it was literally life-saving!
Trust doesn’t work
I do trust the ability of ancient paddlers, but I don’t necessarily trust us to understand what it is they intended. I’m still not convinced the ridge isn’t a cambered back face.
Second, how can you “trust” inconsistent propositions. X and not-X cannot both be true propositions. If a minority of ancient paddle makers made paddles with ridges and a majority made paddles without ridges – both groups depending for their lives on their paddles – which design am I supposed to “trust”. It doesn’t work logically for me.
I’ll await some empirical reports on slicing and rolling with the ridged paddles because there’s more to the sport than a forward stroke.
There’s plenty of info
If you want reports on the behavior of Aleut and GP in various scenarios, you can start reading over at qajaqusa.org, there’s a wealth of info there, most of it very well reasoned and perceptive.
Per your logic argument, there are generally multiple solutions to engineering problems. Neither the GP or the Aleut is a single design — GP and Aleut paddles, with their wide spectrum of sizes, shapes, etc represent a family of solutions to the paddling problem. To pose them as competing designs doesn’t seem particularly useful.
As far as the intentions of the builders in crafting a ridge on a paddle, of course that lies shrouded in mystery. From the standpoint of low-speed fluid mechanics, however, the behavior of the ridge in determining the flow pattern over a paddle is not really an issue of trust, but of analysis and observation.
As far as the effect of the ridge when slicing the blade or rolling, I don’t remember reading anything about a difference between the two. The difference may exist, but I wager it’s subtle, otherwise it would be talked about more often. If it was a real drawback, I bet the Aleut would have discarded the idea — after all, being able to roll successfully is probably more important (as in life-saving) than avoiding flutter.
Someone Handed Me One
out on the water and I played with it some. The ridged side felt power facey to me. It rolled just like a GP.
I went home thinking it was a GP with an annoying ridge in it... and unnecessarily heavy.
A man’s wife would always cut off the end of a roast before cooking it. When he asked her why she did this, she said that her grandmother was a wonderful cook and that’s what she always did.
The next time he saw his grandmother-in-law, he asked her why she always cut the end off the roast. She said that she always did it because her pan was always too small!
Sometimes things get started for practical reasons and then continue on as “tradition by the experts”.
Carl, I’m initially inclined to disagree with some of the general assertions in your post – re designs not competing, multiple engineering solutions (at least concerning paddles), and stagnation lines – but I agree that I should do more research on Aleut paddles.
I must begin, however, with my more than 60 years of observing paddles. The only ones I have ever seen with an aggressive ridge down the center, other than some of these Aleut paddles, are what I would call Walmart paddles. Cheap things, where the builder merely glued flat blades onto a central pole to produce a $25 paddle.
Preliminary reading of forums indicates much confusion as to the power face of an Aleut, but the consensus seems to be that the ridged face is the primary power face, mainly on the authority of someone named Wolfgang Brinck. Some users report greater stability with the ridged face as the power face; others report less power. At least one poster reports flutter when slicing the Aleut.
Do you think the stagnation line concept – assuming it is relevant to paddles at all – relates more to paddle flutter or paddle power? I think the concept of a stagnation point, or small stagnation area, may be a more relevant concept for the power face of a paddle than a stagnation line. For example, a concave and curved power face would increase and hold the stagnation area more so than a convex power face. This increases power.
It seems conceivable that a sharp and abrupt power face ridge might result in a less laminar and “bumpier” water spillage off the face than a smoother and more flowing dihedral convexity. After all, a paddle is rarely pulled perfectly flush to the water, and hence that edge seems as likely to cause drag and disturbance as it does smoothly parted waters.
Finally, I can’t help but observe that I have paddled with hundreds of canoe and kayak paddles that have no excessive flutter and that none of these has an Aleut ridge. Moreover, no racer in any paddling discipline that I’m aware of uses a paddle with an Aleut ridge. If such a ridge solved any efficiency issue – flutter, power, slippage – why haven’t racers rediscovered that solution?
These are questions I’m asking mainly to myself as I conduct some further research. I’m not confident, however, of finding anything truly objective and empirical. Hardly anyone spends any real money doing real research on canoe or kayak physics. I think you told me that.