Friday, June 20, 2014

The Shape of the Unangan (Aleut) Kayak

Unangan and to a slightly lesser extent, Alutiiq kayaks are distinct from the kayaks of other regions in that they are a good deal more flexible. And this flexibility allows any given kayak frame to take on a number of different shapes depending on how they are flexed. And so I thought I would post some photos that show the customary shape of an Unangan kayak, or iqyax^ as the Unangan called it. I've also included one picture of an Alutiiq three-holer. What is notable in all these photos is that on flat water the bow of the kayak clears the water for some distance back. The distance seems to be greater for doubles than for singles, but it is distinct in both cases. Another thing apparent from the old photos is that the deck stringer is more or less parallel to the water line back of the cockpit and slightly rising from the front of the cockpit to the bow. 
Here is an Unangan one-holer probably from the first half of the twentieth century.  The bow clears the water by what looks like about two feet.  Photo credit: Lauren Peters.

An Unangan two-holer with even more bow clearance.
And here is an Alutiiq three-holer in Cold Bay, AK.  Though Cold Bay is in the Unangan region, this three-holer is of Alutiiq style construction.  Note that the paddlers fore and aft are kneeling and the passenger in the middle hatch is sitting. All the same, good bow clearance.
From a functional standpoint, bow clearance helps the bow of the kayak rise to oncoming waves without punching into them. If the bow rises above the wave rather than punching into it, the kayak loses less momentum.  From a construction standpoint, the kayak needs sufficient freeboard, the distance between the sheer line above the water to keep the deck clear of the water. A low-volume flat bottomed kayak does not have enough freeboard to raise its bow very far above the waterline and so it needs more sheer, that is upward curvature of the the gunwales forward of the cockpit to give the bow some elevation.

Friday, June 13, 2014

Unangan (Aleut) Paddle Orientation Revisited

I already have two posts on how Unangan paddlers held their paddles.  To read them, type paddle orientation into the blogger search box on the upper left side of your screen.
Most recently, I have been having conversations with Rob Macks of Laughing Loon Kayaks and he graciously gave me access to some pictures he took of Unangan paddles when he last visited the Smithsonian Institution. Unfortunately I can't post them without the permission of the Smithsonian so I will resort to photos I have posted before.
I haven't seen any Unangan paddles in person, nor handled them.  Rob has. What he pointed out to me is that the Unangan paddles have looms that are roughly triangular with one of the corners of the triangle lining up with the ridge that runs down the center of one side of the paddle.  The looms are also quite deep, commonly about 1-3/4 inches.  The base of the loom's triangle lines up with the flat side of the blades.  What Rob pointed out is that trying to hold the loom with the ridge of the blades facing backwards is uncomfortable because trying to paddle that way has the ridge digging into your palms.
To test the idea of the uncomfortable loom, I carved a loom section out of a piece of two by four with a dimension of 1-3/4 inch deep and 1-1/4 inch wide and roughly triangular with rounded edges so it became more egg-like than triangular in cross section. 
Well, the loom seems a little more comfortable held as shown in the photo below, but not all that uncomfortable the other way around either.  What might be more of an issue, and I have noticed this with one paddle that I made is that a loom with a 1-3/4 inch by 1-1/4 inch cross section is that a loom with these proportions limits how far you can rotate it in your hands to get the right blade angle for efficient paddling.
I will be making a paddle with a loom that is an accurate replica of the Smithsonian type paddles to test this hypothesis.  The idea is that the triangular loom shape will orient the paddle in a favorable way when held flat side back and an unfavorable way when held ridge side back.  
So here is a photo of an Unangan paddler with his paddle.  He looks like a real paddler and so I would expect that when posing for a picture, he would hold the paddle the way he would hold it for paddling, that is, flat side facing backward. Note that the paddler is holding his paddle where the loom transitions into the blade.
This appears to be where you would be holding that paddle while paddling. If you click on the picture above, you will see that that is where the front paddler is holding his paddle.
None of this is conclusive of course, but I suspect that a lot of the dispute about how Unangan paddlers held their paddles has to do with opinions based on Unangan style paddles that aren't very close replicas of the originals.  How you hold a paddle has a lot to do with what is comfortable for you and that has a lot to do with how the paddle was carved and also with how the blades were carved.  Some fairly subtle variations in construction of both loom and blade can easily bias use of the paddle either ridge or flat side towards the back. And as I noticed with my own Unangan style paddles is that I can use them either flat or ridged side back and both ways work although flat side back typically generates more thrust.
Another thing I noticed while looking at Rob Macks' photos of paddles is that on some of them the ridge on the blade was not sharp but rather about a half inch wide and flat.  This type of paddle looked like the basis for the one with the groove down the spine.
One of the paddles in the Smithsonian was also quite long, 8' 6" according to Rob.  It falls into the category of extra long paddles that Jeffrey Dickrell, historian of Unangan kayaks has reported seeing in some historical photos.
So there you have it.  All in all, I suspect that Unangan paddles varied a bit from place to place and from paddler to paddler.  I also suspect that once Russians pressed Unangan paddlers into hunting sea otters for them, paddle and kayak styles became more homogenized than they were before the arrival of the Russians.

Friday, June 6, 2014

Captain Cook and his Expedition Artist John Webber visit Alasks and British Columbia

I got two replicas of John Webber prints.  I thought that they might maybe be actual Webber prints but it turned out that they weren't.  In any case, they are nice prints.
John Webber was the expedition artist for Captain Cook's voyage of discovery in the North Pacific.  John Webber did sketches of landscapes and local people they encountered.  These sketches were later taken by engravers and turned into etchings that could be printed and brought to the attention of a wider audience.

The first print reproduction I got is called A Woman of Prince William's Sound now called Prince William Sound without the 's after William.  Probably nobody outside of Alaska can find Prince William Sound on a map but if you're curious use your google. The only reason anyone may have heard of Prince William Sound it is because the Exxon Valdez oil tanker ran aground there and spilled oil all over the bay thereby impoverishing local fisheries and ensuring decades of work for Exxon lawyers. But that was a little over two hundred years after Captain Cook visited there.  When Captain Cook visited, the primary residents of the Sound were the Chugach people.  And as you can see from the print, the people of the time adorned themselves with piercings, hair weaves and tattoos much as the people of today.
The picture above shows Prince William Sound as it looked during Cook's visit.  Toward the back is Cook's ship.  In the left foreground are Cook's people in wooden boats.  And in the foreground just to the right of center you can see a two-man kayak.  You can take my word for this or you can click on the image above to see a larger version.The kayaks paddled by the Chugach people were similar to the kayaks of the Unangan people farther to the southwest. The Russians made no distinction between the Chugach and the Unangan people and referred to all of them as Aleuts.  And they called their kayaks baidarkas.
The other print I got was of the Man of Nootka Sound. Nootka Sound is on the west coast of Vancouver Island some distance south of Prince William Sound. People there likewise adorned themselves in modern fashion but paddled wooden dugout canoes instead of kayaks.

The drawing above and the one below are the Webber originals.  These are what the engravers used to base their engravings on. 

Friday, April 11, 2014

El Toro Trailer, Updated

You probably don't remember but a while back, I did a posting on kayak trailers that could be towed behind a bicycle.  The tow bar on that one broke.  The fundamental problem on that one was that it was made out of a fairly skinny piece of redwood that just wasn't strong enough.  This time I used oak.  Oak is stronger but the bar sticking out from the trailer is still about 8 foot long and so it flexes quite a bit.  When you're pedaling, the rhythmic motion of the pedaling sets up a back and forth oscillation of the trailer which is not only annoying but also slows down progress.
There it is with an El Toro loaded up for a test run. The length of the tow bar might seem extreme, but it has to be long enough to tow 20 foot (7m) kayaks.
I knew how to fix the oscillation problem which is by adding some cross braces in the form of a triangle, the universal stable polygon. But due to lack of ambition, I never got around to it.  But since the tow bar broke and I had all the tools out to replace it, it was time to add the bracing as well.  Mission Accomplished! as George Bush would say.
And the view from the rear.  The El Toro, an invention of the Richmond Yacht Club is 8 foot long and 4 foot wide.
Tow bar triangulated with two side braces for lateral stability.
And the link from the tow bar to the bicycle.  I should shorten that. Next time.

Desert Storm Tan Repaint

Over the last few years I have been painting the skins of my skin on frame boats with polyurethane varnish.  The varnish has UV blockers in it that protect the synthetic boat fabric from degradation by the UV.  The fabric I use is either nylon and of  late, mostly polyester.  Both get degraded by UV more or less equally.  Degradation means the fiber loses its flexibility and strength and crumbles into dust.  This is not a good thing in a boat skin and so it must be prevented.
In the past, I would try to touch up the varnish.  That worked for a little while but new polyurethane does not adhere well to old polyurethane.  The touch up varnish when exposed to sunlight for about a year starts to peel off.
Here's the original latex painted boat,  exposed to full sun for over two years already with no visible damage to the paint.
The solution as it turned out is latex paint.  Latex paint sticks to degraded polyurethane varnish and it effectively blocks UV radiation and it also is more flexible than polyurethane and does not crack.  Coincidentally, the polymer used in latex paint is acrylic, same stuff that they make UV resistant fabric like Sunbrella out of. You might ask, why not just cover the boats in sunbrella.  Good question.  I suspect it has to do with the price of sunbrella.  And you still have to paint the stuff to make it waterproof.
Here's the King Island kayak about to get a coat of tan paint.  Note the previously yellowish varnish starting to turn a chalky white, a clear sign that is near the end of its life.
The paint I was using was free give-away stuff left over from repainting about an acre's worth of commercial buildings in the neighborhood.  The commercial buildings have not peeled and neither have my boats.  Only drawback to this paint is its color, an unattractive sort of Desert Storm Tan.  Oh well, I also have four gallons of Gulf of Tonkin Gray.
And here is one of my baidarkas with a new coat of Desert Storm Tan or maybe it should be called, Afghanis-Tan or would you prefer Afghanistan-Tan
In any case, I painted about 4 boats yesterday.  Six left to go.

Wednesday, April 9, 2014

Basic Technology by Michael Wolf

Michael Wolf is a photographer working out of Hong Kong and possibly other cities.  A while back I ran into his photos of what he called "Bastard Chairs."  I would have picked a more flattering term, but bastard chairs is probably what most people would regard them as.  In any case, these chairs are what you get when people who are not professional chair makers improvise on chair repair.  They are in a sense, folk technology.  Go to the link to see more examples.
Housing is another area where folk technology proliferates.  And Michael Wolf has done photographs of that as well in a photo group called The box men of Shinkuju Station.
How does this relate to skin on frame kayak technology?  Well, given a need, people will invent a way to make do with what they have.  That is the essence of most primitive technology.  In our own very compartmentalized world where everything has to be done by experts we are usually isolated from folk technology and instead overwhelmed by what we commonly think of high technology.  But inject poverty and take away the money that it takes to fund the expert technologists, voila, up pops folk technology like mushrooms after a rain.

Wednesday, February 26, 2014

Eastern Arctic-Like Kayak, Performance Report

I finally did it. Finished the EA kayak with some deviations from the traditional norm, painted it and headed out to the water to see how it paddled.
There it is by the side of the water.  Launch imminent as soon as I get in and start paddling.  Weight is between 50 and 60 pounds I'm guessing.  Length is just short of 18 feet about 16 of which are in the water. Beam is somewhere around 27 inches. Two paddles are resting on the boat.  One Greenland style, 88 inches long and the other, an Aleut style with a 3 inch wide blade at 120 inches long, yes, that's right, ten feet long.
The big question was what sort of speed a flat bottomed boat could be paddled.
I had my GPS with me.  At the start of the test while I was still fresh, I managed to get the boat up to 5.6 mph. Cruising speed seemed to be between 3 and 4 mph. I did my usual two mile circuit once around Ballena Island. Wind was variable, maybe up to 15 mph and wind blown waves were about 1 foot max.  So not much of a rough weather test.
Overall, the boat seems to move about adequately.  Turning with the flat bottom is easy.  The boat responds quickly.  I thought that staying on track might be a problem but it turned out not to be.  The boat had no particular tendency to turn into or out of the wind and it had adequate length so it wasn't yawing right and left with each stroke.  Paddling both down and upwind was possible without any undue steering effort required. So all in all, the boat performed well.  I would still like to take it out on a rough day when waves are more like two feet, like a normal summer afternoon on the bay.
I ended up using the 120 inch paddle for most of the trip since it seemed to be a better match to the boat than the 88 inch paddle which required more effort to reach the water.
Overall, I felt that I needed more experience with the boat.  The initial outing left me feeling that its weight and speed was such that I need to discover some more positive attributes for the boat or it would not get much use. 
Speed is of course an ill defined measure.  What matters is efficiency.  Overall, the width and flat bottom of the boat are a combination that require a good deal more effort to make the boat go than just about any other kayak style that I have built.  If I were to build another version of this boat, I would probably decrease overall width and increase flare to the sides from the 10 degree flare that I put into this model. Increased flare would decrease the width of the bottom. I probably would also go with bent ribs to reduce weight of the boat and have some V in the bottom.  With lighter weight and less resistance  to movement this style of boat would be adequate for recreational use.
As I mentioned earlier, the boat also needs some rough water testing to see how the flat bottom handles going over waves.

Sunday, February 23, 2014

Eastern Arctic-like Kayak - closing comments

Time to bring the EA kayak building project back to life, on this blog anyway.  Time to make some comments on the building experience, a time when the building is done but the boat hasn't been in the water yet and provided feedback on its suitability as a water craft.  I could have waited another few days to comment on the completion, but I'm thinking that once I try the boat out, I will become preoccupied with how the boat handles and forget all about what I learned from building it.
Part of what building an actual boat is all about is internalizing its structure in three dimensions.  Plans are flat representations of a boat and typically don't show any more than a top and a side view and some cross sections.  But the flow of the form of a boat in three dimensions is a lot more complex than the plans show and to get a feel for the form, you actually have to build the boat.  Once you have the feel, you gain the understanding of how that form interacts with the water and determines performance.
In any case, if you did some careful reading of the title of this posting, you may have noticed that called it Eastern Arctic-like Kayak.  What I mean by that is that when I laid out the shape of the kayak in the horizontal and vertical planes I improvised, that is, I didn't follow a particular plan but rather adapted length and beam to fit the wood that I had available.  I came close to building something that could be called Eastern Arctic, but not quite dead on.  Let's look at some photos.
Here's a picture of the frame just before the skin went on.  If you let your eye follow the right gunwale line you will notice that it has some bumps in it.  I think in general EA kayaks had a smoother sheer line.

Here's a shot of the boat frame. Bow down.  As you can see, the plan view is more like a Greenland hull than an Eastern Arctic.  Part of the problem with working by eye in a tight space.  Should have dragged the frame outside at deck setup time for a better view and probably would have noticed that the back end should have been wider.  I suspect the boat will behave ok, just with a narrower stern won't have as much carrying capacity.  And anybody who knows anything will feel compelled to tell me that I didn't make the back wide enough.  Yeah, I know.
View from the side with the skin on.  The nose is unorthodox, a little taller than traditional.  Looks more like a northwest pacific canoe bow.  Also the sheer line is a tad extreme.  We'll see how that works out.
Meanwhile, the cockpit turned out more or less standard, maybe a few inches longer than traditional.  Soon this boat will have some paint and then hit the water.  Till then I'm holding off on any predictions re performance.  I am most curious to see how the flat bottom will feel and how much stability vs. speed tradeoff there is in such a flat bottom.  Stay tuned.