Friday, June 19, 2009

ergonometrics in reverse

Fellow kayaker, Duane Strosaker pointed out to me that I haven't posted since forever. So here goes, more postings.
Today's topic is ergonometrics in reverse.
Ergonometrics is generally defined as using parts of your own body as a yardstick to measure lengths. Before measurements were standardized, everybody used to measure this way.
Ergonometrics in reverse is the measuring of your body with a tape measure to see how it will fit into your kayak.
In the picture above, I am lying on my back on a plank which is balanced on chunk of wood. The point is to slide back and forth on the plank until both the plank and I are balanced. Then I can measure from my feet to the balance point and record the number.
You could also do the same procedure sitting up. This would give you the location of your center of balance when sitting. When you position your own center of balance over the center of buoyancy of your kayak, then in theory, the kayak should trim correctly. The only problem is knowing your kayak's center of buoyancy. If you are a techno weenie and have a naval architecture cad program on your computer and actually know how to use it, then finding center of buoyancy is no problem. Such people do exist. I have seen them posting to kayaking discussion groups.
For the techno deficient among us, we have to proceed by trial and error. Once you have built a boat, you can simply move weight forward and backward in the boat to figure out where the boat trims correctly.
In my case, I already knew where the center of buoyancy of my next baidarka would be. Only problem was that instead of sitting in the kayak, I wanted to be able to recline in it. And that's why I needed my own center of balance or longitudinal center of mass when in the reclined position so I could position the long recliner style cockpit correctly.
I will be posting on the baidarko-lounger soon.

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