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Sabtu, 15 Oktober 2016

Unangan Single Bladed Paddle to Double Conversion and Back Again

When I first saw this picture of a double bladed paddle, I thought it was a new Aleut type.  And so I made a copy of it.  As it turned out, it was too short for me and I never used it after its original trial. Later, the photo showed up on some forum and somebody perceptive pointed out that the double bladed paddle looked like it was two single bladed paddles lashed together, possibly after having been sawed to better fit together. Sure enough, if you look carefully, you can see the lashing that made one paddle out of two.  The picture was taken at the Chicago Field Museum when it was the site for the World Fair.
The problem with using a single bladed blade shape for a double-bladed paddle is that the single bladed paddle is designed to be used more or less vertically so that the full blade is immersed in the water at then end of the stroke.  The blade on the double bladed Aleut paddle is widest near the tip so you can get more blade in the water at the beginning of the stroke at a lower blade angle.

Click on the photo for a better view.  Note the single bladed paddle tucked under the improvised double bladed paddle.
Just recently, it occurred to me that the one paddle out of two process could be reversed and if I cut my too short double paddle in half and spliced some more wood to it. Then I could have two usable single bladed paddles instead of just one unusable double bladed paddle.
The double cut in half on a bandsaw. The half on the right already has its extension glued to it. 

And here, a close-up of the sliced portion of the paddle.
Soon as my paddle transformation is complete, I will report on the performance of these paddles.
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Kamis, 22 September 2016

Single Bladed Paddles Get a Tank Test

Ive been working on a bunch of single bladed paddles for a number of reasons.  The first is that I was making a single bladed paddle blank for one of my kayak students. And once I got going on that paddle, I thought, why not make a bunch more. The second reason is that when I make double bladed kayak paddles,  I always have some thirty inch lengths of wood left over that I cant use on the double bladed paddles but that are long enough for single bladed paddles.
So I got four paddles roughed in for myself, two are the Aleut single bladed paddles I made out of a double bladed paddle that I had cut in half.  Go back a few posts for the details on that. And two of the paddles were canoe paddles of roughly Ojibwe style.  At least I think one of them is since its based on lines I took off a paddle I saw at the Ojebwe Museum in Lac Du Flambeau, Wisconsin.
Photo of my SOF canoe at the Encinal boat ramp on SF Bay.  The dark blue part is the Bay.  The medium blue stripe along the horizon is the SF peninsula.
Heres a 3/4 shot of the canoe with paddles spread out for the photo.
A better view of the paddles from the blade end.  The two on either side are the two halves of the former double balded Aleut paddle.  The second from the left has an eight inch wide blade and a length of 64 inches.  The third from the left is based on the paddle in the Ojebwe Museum.  The blade on that one is six inches wide and total length is 68 inches.
And this is a view from the end of the handles.  The two middle handles are based on traditional Ojibwe samples.  The two on the outside are tee handles mortised to the ends of the paddles.  After taking the paddles out I decided to round over the outside edges of the handles some more since I found myself using them with the upper hand on the outer edge of the handle rather than square in the middle as you might think.  This is the kind of thing one discovers on tank tests.
What found on the tank test was that I really liked the Aleut paddles even though they had less surface area than the other two canoe type paddles.  On the other hand, the canoe paddles, especially the one that was 68 inches long worked better for paddling on one side only by transitioning to a rudder stroke at the end of each propulsion stroke.  With the Aleut paddles, I had to do two strokes on one side then switch to the other side to get the boat to swivel back in the other direction.  Im not sure why that was, it may simply have been that with the canoe paddles with their bigger blade area I was able to do a rudder stroke more easily.
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Jumat, 01 Juli 2016

Fire Good Fire Bad and Whatever Happened to Pyrodiversity


I recently bought a book called California Indians and Their Environment. California Indians unlike most of the other Indians in what is now the US had never developed any agricultural technologies.  Instead, California Indians made their living exclusively off plants growing wild in their environment.  However, Indians managed their environment by burning practices that encouraged their food and medicinal plants to thrive.
Enter the Europeans.
Fire, an environmental management tool for the Indians was a threat to property for the Europeans.  The use of fires intentionally set  by the Indians, what are now called prescribed fires was outlawed by the Europeans. I imagine that the dwellings of Indians were subject to fire damage just like the dwellings of the Europeans but given  that the Indians set fires to manage the vegetation in their territory did not build dwellings where they would get burned down.  In addition, Indian dwelling may have been more temporary or movable and therefore more disposable or more easily relocated if a prescribed burn was called for.
I have never seen the reasons for antipathy to fire spelled out anywhere in text, but the idea that fire is bad seems almost self evident probably at least in part because of a massive public relations campaign by the department of Agriculture.  The appeals were mostly emotional and aimed at a population that probably had very little contact with forests on a day to day basis. The reasons for preventing forest fires are primarily economical and have little to do with ecological concerns.  Fire is a natural phenomenon and ecosystems have adapted to fire and in many cases depend on fire to keep the ecosystem in balance.  Not so in National Forests managed by the Department of Agriculture.  National forests produce lumber.  The lumber is sold to lumber companies and the Department of Agriculture collects money when the trees are cut down.  Trees that go up in smoke dont produce any revenue and whether by training or by natural disposition, most people, myself included dont like the look of burned over forest. 
The National Park people on the other hand dont sell any lumber and so they can afford to let forest fires burn.  No revenues are lost as a consequence.  Perhaps park attendance goes down during a forest fire but quickly picks up again afterward.  National parks even do prescribed burns since some trees like the giant Sequoias dont reproduce unless the ground is burned over.
But back to the Department of Agriculture anti fire campaign.  While the motivation to prevent forest fires was primarily financial, the advertising campaign instead focused on the fact that forest fires could potentially kill cute baby deer and bears, and so Smokey the Bear was created.
OK, so fire wastes resources, not to mention displacing or possibly orphaning young deer.
Heres the orphaned deer theme again.  no mention of wasted resources this time.
And again, this time, who knows, might be Smokeys nephew thats getting bandaged up there.  Smokey wants to know WHY?
This time, no orphaned animals, but the implication is clearly that those two cubs would be in a heap of trouble if there were to be a fire.  Smokey meanwhile is taking a break from shoveling dirt on top of camp fires to read a fan letter.  In the background, city dwellers recreate on a lake in the woods at a forest service campground in an environment of statuesque ponderosas unmarred by fire.
And for the children, a reminder that theres lots of critters that would be indisposed by forest fires, the advertising campaign bleeding out into the culture at large via childrens books.
And finally, WWII poster.  Needs an update there with Putin and Osama.









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