Instant Yuloh

There was one more thing slung on top of the canoe during that tugboat expedition at the end of the last post, just to push the oddball-look a bit closer to the edge of absurdity. In our age where for fetching a bottle of milk at the corner store we use a petrol powered car and to peel carrot we need an electric machine I do try to make a point of using my able body whenever possible, bare and without help of artificially produced energy. So there I was, like a madman paddling into the wind with two thirty foot long glassed bamboo spars in tow in the water behind me and a giant yuloh strapped onto the slim hull of the outrigger canoe, and just to push the envelope a little bit further I solemnly put the paddle down and fumbled for the mobile phone in the pockets of my pants. I wanted to call Beatriz, who was on board Aluna out there on the mooring, to have her take a couple pictures of my regal arrival. This had to be done quickly before the wind pushed the canoe’s bow over to the side so much it would be impossible to straighten it back with the drag of the load attached to her sterns. Unfortunately the call didn’t get through and the phone almost slid out of my hands into the water. No visual evidence of this rather unusual event is therefore preserved for posteriority.

What’s a yuloh, my friend Tony asked, when I texted him after the successful completion of the task. There was no way I was going to give him a detailed description thumbing on the numerical buttons of my not very smart phone, so he got the short version. Chinese sculling oar! Since I’m sitting in front of a standard computer keyboard now, you’re lucky. You get the full version.

The Chinese have been a seafaring nation for millennia. While maybe not precisely to the tune of the fantastic accounts of Mr. Gavin Menzies they have come up with some nifty gadgets that make the harsh life on the seas a bit more feasible. Most mariners of European decent when using their own muscle power to propel themselves across the surface of the water row with their back turned towards where they are heading and waste a good percentage of their energy in repositioning the blade of their oars and their upper body to the beginning of the power stroke on each and every cycle of their art. I have tried every possible contortion of my neck and upper spine to make reasonably straight progress towards a desired destination in that way. I therefore early on in my maritime career opted to resolve the first one of these rather serious obtrusions by adopting the style of our brothers living in the vast expanses of the Pacific, which is also used by many other indigenous people around the world. I paddle our tender, which is a slim canoe. That means not only can I see exactly where I’m going, but I’m also able to precisely alter the stroke to influence the direction of the craft. I can even instantly turn the paddle into a steering blade if that’s needed for a particular maneuver. This does nothing however to solve the second issue of the wasted energy through the intermittent nature of the stroke.

Here is where the yuloh comes to shine! There is a vanishing art in the European realm as well called sculling. It has gone a similar way. A long and slender oar is used over the stern of the boat and moved from side to side. The Chinese have refined this idea to the point where a single man is able to move a heavily loaded junk with apparent ease through the backwaters of the Shanghai markets and back up the river to his home out in the country side amongst the verdant rice paddies. Two technological tricks are involved in the improvement. For one there is a bend in the oar’s shaft or loom of somewhere between ten and fifteen degrees, lowering the blade close to vertical into the water. Then, apart from sitting firmly on a fulcrum at the stern of the boat, it is also connected with a piece of rope tied to the handle to the floor of the boat where the operator is standing. In fact the yuloh artisan has only one hand on the handle of the oar while the other one moves that piece of rope from side to side ahead of the handle, so as to make the required twist of the blade almost automatic. The result is a propulsion tool that is in fact much more a single blade of a propeller than an oar. Its side-to-side motion mimics the natural movement of a leave falling through the autumn air.

On one of Aluna’s first outings and subsequent tense return to the fingerdock of the San Leandro Marina, where the stubborn second or probably even third hand outboard motors had refused to start up, we came into the maze of fancy maritime real estate under sail. Since then I longed for a way to propel her with my own arms and hands over short distances in emergency situations. At that time I had grossly misjudged our brand new vessel’s turning radius and her ability to make headway into the wind once head on, and we found ourselves stopped dead in the water about 20 meters short of our spot on the dock and started to drift straight towards a shiny shell of immaculately waxed gelcoat. Luckily we had our good friend Thomas Nielsen on board! While I stood there wide-eyed scratching my balls, I mean, my glaring boldness, Thomas reached into the pockets of his pants, handed me his latest and greatest model smartphone, and next thing I saw was a splash in the water and him swimming with a rope clinched between his teeth over to the dock. We easily pulled Aluna home with that rope.

I set out to fabricate a rudimentary paddle with a three-meter handle out of an offcut from the pine sapplings used for the first version of the spars. With that I’m able to stand on Aluna’s aft decks, dip it into the water over the sides, and pull at it with all my might. It is quite helpful when having to go through the eye of the wind in very light air, when the boat’s speed is so minimal that it just can’t do so on its own, but its efficiency is rather limited. That’s how the yuloh had established a firm place on my list of pending projects, and while it sat there eternally in the waiting line I had combed the internet down to its most obscure and rarely visited corners and absorbed any and all tidbits of information I was able to light up on the computer screen. But years went by and I never got around to start the actual process of designing and building it. When I looked at the two offcuts from the two bamboo culms for the spars, they stared back at me, impeccably dressed in spiral wrapped and already faired fiberglass, and begged: Do something! Don’t just let us sit here and go to waste!

I had never even gotten to the point in the yuloh project where you sit down and do scale drawings based on the real measurements, but I had rolled the idea of it around in my head for so long that I decided to walk the fun route and wing it. After all, James Wharram’s profoundly human concept of the functional sculpture gives all us hobby engineers a very broad artistic license. And since our modern world seems to suffer from a rampant over-rationalization of just about every aspect of our lives, I said to myself: Let’s play around with it a bit, shall we?

The angle in the loom should be around 11 degrees. That much I had distilled from the various texts and treaties on the net. Easy enough! I cut the ends of the two bamboo sticks at the corresponding angle to end up with a scarf joint to spread the load over as big a glue area as possible, fasten them together with sufficient epoxy and then wrapped some more of my leftover glass cloth around it, covering the culms about a foot on either side of the joint.

yuloh1 yuloh6The blade was a bit more complicated. On most of the pictures I have seen, the yuloh blade is thin and long and benefits from a certain elasticity. Looking around in the shop I couldn’t set my eyes on anything containing such a shape. But again there were leftovers staring at me. It looked like re-utilization would be the theme of the day. There was roughly a quarter sheet of the 4mm ply leaning against the wall, left over from the ama project. The problem with it was that there was nowhere close to the required length left on it without having to do extensive scarfing. Since my self-esteem always seems to thrive when I can do something different than everybody else, I talked myself into making a much wider blade to get a similar surface area.  A little playing around with cardboard mockups pretty quickly revealed the most effective use of the plywood scrap. Three ribs provide the profile of the blade, which needs to be curved on its forward side in order to provide lift. Panels glued onto these built the basic shape. The aft side is usually left flat and there I didn’t feel any need for rebellion.

yuloh2 yuloh3 yuloh4 yuloh5 yuloh7These were my last two days in Ted’s workshop. So things had to fly together fast. Ted’s long sailing vacation up the coast was coming to an end and we were departing the Bay of Islands for a mission to the metropolis. What came out of this sprint on the final stretch is a curious contraption. Just to find a place to store this angled thing on board Aluna turned out to be a major headache. An odd sculpture it is for now, its functionality not yet established. When we’ll be back it will have to face the reality and prove its usefulness. I’m just about certain that it is but a first sketch of an evolution. Nothing comes easy in the world of technology, and that is a very, very good thing!

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2 Responses to “Instant Yuloh”

  1. Beatriz Restrepo Says:

    Hay que seguir experimentando hasta que se refine la idea!!!!

  2. Yuloh gonna love this. Or, how I’m handling my first engine repair. – STEADY AS SHE GOES Says:

    […] Another sailing blog and the joys of using a yuloh. […]

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