January 12, 2010

YRVINDS YULOH

The picture below shows the essential yuloh geometry. There are three points of importance. The centre of effort or pressure on the oarblade. The fulcrum and the point were the rope is attached. If you draw a straight line betwwen the centre of effort and the point were the rope is attached the fulcrum shall be a inch or two above that line to keep the thing in balance. Exactly how much is depends on personal preference.

The curvature of the traditional yuloh fixes these three points. On my boat it is not possible to have a curved yuloh as I will store part of my yuloh belov the fore deck in a carbon fibre tube. My yuloh is therefore straight.

To get the essential geometry I have added a removable piece at right angle to the shaft. At the end of that is the attachment point. By varying the length I can adjust the balance. That solves the problem of stowing the oar. It is also very convenient because I can use a straight pipe as oar shaft.

An other thing. Some people like to have the rope doing the twisting of the oar blade at each stroke. I do not agree, neither do the Japanese scullers. They have a technique that differs from the. They have a small handle at right angle to the oar shaft a bit like wrench to twist the blade to the desired angle. In that way you have control and can use the oar blade as an variable pitch propeller. Going against strong winds you use little twist and get much power but the boat mows slow. In calm weather you use much twist and the boat goes faster.

The yuloh traditionally uses a ball and socket at the fulcrum. It is simple to make but a universal joint like mine shown below has several advantages. As a yuloh replaces an engine and I use it a lot I do think it is worth to spend time and money on a better fitting. First the oar cannot jump out of the socket. Second it enables one to scull in reverse and row the stern around. This is very convenient when one maneuvers in tight places. And I do like to get into tricky places to discover interesting things.

....

Yuloh design cycles

Posted by timesuptim in Boat Building, CoC, Traditional and Regional Boats

We have decided to use a Yuloh paddle on the Subak. There are a number of reasons for this, including simplicity, facing forward, efficiency, wanting to experiment and probably a certain aspect of wanting to just be bloody minded and difficult. We had seen videos of people moving (even huge) sampans(apparently up to three knots!) and adaptions (e.g. the Ve-scull) that are quite quick. So on Saturday we wasted too much time making a Yuloh while the wind blew, then launched the Subak into a windless harbour a few hours later.

The new Yuloh socket is cut out of a larch verandah plank, then drilled at 45 degrees to match the mounting angle, then a wider hole to allow the yuloh to tilt on each side.

The first experiments with the Yuloh tied onto the transom were surprisingly successful, although quite wrong in many ways. We then built a socket and a pin for the Yuloh and mounted it on the stern. This socket, cut from some hard plywood, was put onto a rounded head screw as the ball joint and was a semi-successful improvement. The plywood had been significantly worked over by the attachment and the work: this seems to be inappropriate.

We then took the design advice from a Yuloh design text (which we had approximately used previously) and made two major changes: the socket was cut from some larch planks we had been left with from someone’s new verandah, given a 45 degree basic drilling to support the correct angle of the yuloh, and the mounting on the stern was raised 30cm. The mounting on the stern is now a simple 12mm steel rod with a round head, shaped with a grinding wheel, as recommended here. The main problem is the danger of bending over and sticking the rod in one’s eye!

Tests this afternoon with the new socket are positive, but there seems to be a one sided tendency of the movement. This might be that the hole is asymmetric (it was end-shaped by hand) so that the angle of the yuloh on each stroke is different. It might be that I was not standing appropriately centrally, so that the whole movement was off center. The Subak is asymmetric, with the windsurfer dragging off to starboard, so that might have been causing the spin. Tomorrow morning the next experiments and tests will be done. Let’s see what happens.

The $10 Yuloh!

A cheap introduction to "scientific sculling."

If you're like me, you think of sculling as a kind of inferior form of rowing only to be resorted to when you've lost an oar or are trying to maneuver in close quarters. The way I learned to scull and the amount of time I gave to practicing, it is best left as method of last resort. However "yulohing" has been described as "scientific sculling" and it has remained the oar locomotion of choice in the Orient for hundreds of years and maybe longer. Was it only a matter of long standing tradition that kept the Chinese or Japanese from adopting western rowing techniques once they were exposed to them? I think not. Let me try to explain the Yuloh's advantages.For those of you who have researched outboard motor auxiliaries for sailboats you know that larger props moving at lower RPMs render more torque than smaller props at higher RPMs. This same principle can be applied to oar blades. Being bigger, the Yuloh is not capable of being moved very quickly, however the long Yuloh blade with a surface area many times that of a traditional western rowing oar displaces a lot of water as it moves. Like the western oar, the Yuloh makes use of a fulcrum and a lever, however rather than merely having your muscle and your body weight at the working end of the lever, you have a lanyard attached to the deck or bottom of the boat. This gives great assistance to the rower in counteracting the pressure of the water against the business end of the blade, which translates into forward thrust. Whether from the flex of the Yuloh blade or the snap of the lanyard at the end of the arc of the stroke (see notes below), there is power and forward thrust coming from the yuloh blade all the time it is in motion. Now this bears contemplating. Notice that when rowing there is always a coasting component to the stroke. As the oars are lifted from the water and returned to their power position, energy is being expended that is not directly applied to moving your craft. With the Yuloh this isn't the case. As you are leaning to and froe, all of your movement and body weight and strength is being translated into forward thrust.
Add to the above advantages the ability to propel a craft that might be too wide to row, and the ability to face forward and see where you're going, and you can begin to understand the reasons behind its long lived popularity.

The materials I started with:

one spruce 2x4 8 feet long ($2.49)

one spruce 1x6 8 feet long ($3.99)

one 3/8" galvanized carriage bolt 6" long + 3 nuts and 2 washers

one 1/2" PVC pipe cap

6 - 1.5" galv. deck screws

PL Premium glue (could substitute Titebond II)

Added later:

1/2" polybutyl tubing - a couple of inches

7/8" dowel rod 6" long

After examining all the literature I could lay my hands on, (A huge thank you to Craig O'Donnel, who proved to be his usual font of information.) and checking a bevel guage against my shanty dock sketch, I settled on 11 degrees for the angle between the blade and the shaft or handle of the oar. I drew the angle on the 2x4, then began the cut with my circular saw and finished it up with my Japanese pull saw. Save the piece you saw off to help you clamp the joint.After this cut I did the taper cuts on my table saw. The blade tapers from 5.5" at the water end, to 3.5" where it joins the shaft. The shaft tapers from 3.5" where it joins the blade to 1.75" at the end.

My research showed the aft side of the blades to be flat while the leading sides were either triangular in cross section or curved to give lift like a mini wing section. I personally question the validity of the "lift" aspect of the Yuloh's thrust, but decided to split the difference and make a three sided leading face.The blade stays 3//4" thick in the middle but tapers to 3/8" thick at the edges. I tilted the table saw blade to 13 degrees and ran the oar blade against the saw fence. Leave it square where the glue joint will be. Since I did this step after cutting the lengthwise taper in the blade, the top face in the photo narrows with the blade while the outer facets maintain their width.
I also rounded all the edges on the shaft with a 3/4" round over bit in my router.

Testing the fit of the blade and shaft.

Apply glue and clamp. The wedge you cut off earlier will give you a parallel clamping surface. Since I was going to use mine before the glue had fully cured I also used four 1 1/2" galvanized deck screws. I used PL Premium glue because I like it so much, but I'm pretty sure Titebond II would work as well.

Here's a look at the wear that resulted from just a few minutes of sculling with the first pin attempt without the poly butyl tubing. It chewed up the cap edges pretty quickly. I counted on the plastic pipe caps to be expendable and easily replaced, but not with every use!

Here is the pin and cap ready for use. The pin is a 6" by 3/8" carriage bold with a short piece of 1/2" polybutyl tubing held in place with a washer and nut. This both limits wear of the cap edges and limits the side to side travel or tilt of the pin in the cap. That in turn limits the feathering of the yuyloh.The cap is inset in a 1/4" deep hole the diameter of the cap. It's held in place with a galv. deck screw, that is countersunk into the inside of the cap.

Here is the pin in place in the cap.

This is the cap after about an hour of sculling, and the wear is negligible.

My original idea was to drill a hole through one of the boards in my shantydock, and tighten it with nuts and washers top and bottom. Turned out I had a bronze oar lock that was more easily movable for experimentation so I used it on my motor mount.Here is the pin in the oar lock. I've secured it with another washer and two more nuts, the last acting as a lock nut against the first. This places the pin vertical. If I needed more slant to the oar, I'd have to mount the pin at an angle as well.

The oar is amazingly well balanced. The shaft is slightly heavier than the blade so when at rest, the blade comes clear of the water.

Some observations:I'm finding that limiting the amount of feathering is the challenge. The oar is wanting to rock off the pin. If I only hold the lanyard it will over feather. I'm not sure if this is the fault of the pin mount or the angle of the oar offset. I chose 11 degrees while some claimed 8 degrees was the ideal. Though my GPS wasn't working I got the shantydock moving pretty well judging by its wake, even into a light breeze.
Some of the instructions claim a "snap" of the lanyard is necessary at the end of each stroke. I'm not finding this to be true. What happens is the blade flexes during the stroke and when the end of it is reached the blade straightens and the oar rotates into the new feather angle. This is without my assistance. It makes me feel that if the tendency to over feather can be cured adapting the oar to step power should be pretty workable.

A short wooden handle off the top of the shaft, as shown in some of the drawings, might be useful. This would be to counteract the feathering tendency of the blade. Though subtle steering can be done by pulling harder on one side of the stroke than the other, its more dramatic to alter the feather of the blade. For most decisive turning the blade can be "un-feathered" meaning trimmed horizontal so it travels back to the other side without imparting thrust at all. A handle would greatly facilitate that control.

Return to the Yuoh Resources page.
Feel free to email me, David Beede simplicityboats
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For the article about this project, see: http://sailingauklet.com/2013/10/13/the-yuloh/

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Removable post, to raise transom pin to correct height.

Shemaya, and all that seizing in progress.

Raised out of the water by double-wrapping the lanyard. Chain weight "training wheels" also in place.

Chain wrapping for additional weight, to prevent jumping off the transom pin. Approximately 1 lb. 12 oz., 4 feet of 3/16" chain. Ankle or wrist weights meant for exercising would probably be easier.

Transom post, with bicycle trailer hitch; yuloh loom sockets.

Yuloh in position for use, blade raised by wrapping lanyard twice around handle.

Demonstrating at the dock, with a pretty good current from the stern, as seen by that big whirlpool.

And one more, showing the tie-point for the lanyard.

Chain wrapping for additional weight, to prevent jumping off the transom pin. Approximately 1 lb. 12 oz., 4 feet of 3/16" chain. Ankle or wrist weights meant for exercising would probably be easier.

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How to Scull a Boat

Article taken from WOODEN BOAT #100, June 1991. Many such articles are in each publication and provide a wealth of information to the Boating Industry. Please purchase and support this magazine. Reprints can be obtained at the Wooden Boat web site or by calling or writting WoodenBoat Publications Inc PO Box 78, Naskeag Road Brooklin, Maine 04616 USA ........Tel: 207-359-4651 Fax: 207-359-8920

Text and illustrations by S.F. Manning

Click on each image to make bigger.

"Notch" snorted Robbie Weatherford as he swept up an oar from the float. "Ye don't need a notch if ye do it right!" With that he thrust the Oar over the side of the float we were standing and began a vigorous twiddling with it that sent wavelets breaking into the mangrove roots ,just beyond. I could feel the float depress under the force of' his oar. As he yanked it back and forth while demonstrating how a sculling oar should be handled, the loom of that oar stayed right where he'd placed it on the edge of the float, There was no notch or crack or anything there to keep it put.

Happily, I'd remembered my mother's admonition that you never tell it cowboy that you can ride a horse. You say, "I'll try." And try I did for that 75-year-old Man 0' War fisherman who'd sculled boats all his life the Bahamian way. But I couldn't get the oar to stay put without restraint where it crossed the edge of the float.

The fact is that I too, have been sculling boats all my life , starting on a farm pond way back during the Depression. But up North we do it differently or perhaps I'd never taken notice of how other people scull boats. Robbie's stroke was more powerful than mine .He could make it Man 0' War dingy-boat move as if it were inspired by a small outboard. His oar was straight, narrow bladed, and fully as long as the boat he sculled. Bahamians scull. They do not row, with two oars, nor do they use sweeps. It was once common to see a Bahamian sloop or schooner being sculled by a single oar over the stern when the breeze failed. A single long oar is often primary or auxiliary equipment in boats of that region. The sculling notch, if used at all, is very shallow.

What is sculling? Sculling is traditional way of propelling a boat or vessel through the water by means of a single oar mounted on, or worked from the stern. Consider the various types of oars and how they're used. A paddle is gripped in the hands and is pulled independently of the boat. A rowing oar is pivoted through a lock on the gunwale or a port in the boat's side and is pulled or pushed from a position just inboard of' the pivot point. Small-boat oarsmen normally pull two oars at once over opposite sides of the boat. A sweep is a long rowing oar that is pulled through it pivot point located oil the opposite side of the boat front the oarsman. A scull is another name for a shortrowing oar. A sculling oar call be a rowing oar, a sweep, or even a paddle operated through a pivot point in a propeller-like stroke that pushes the boat front behind. A breed of oars specialized to sculling has evolved in many, parts of the world over millennia The best known of these are the Bahamian oar, the "slat" of tile Chesapeake watermen the bent scull float oar of the duck gunners, and the yuloh of the Chinese. We'll examine the strokes used by scullers, and then we'll have a look at the various oars.

Allied to Sculling, and Sometimes described as sculling, are two types of stern propulsion that most boatmen have done at one time or another. The first might best be Called "levering" This entails jamming all oar blade straight down over the stern and giving the loom at hearty yank forward. A boat moves convincingly, if erratically' this way. The second might be called "fishtailing." Here the tiller of, a small boat is it quick yank in one direction and then a quick yank in the other, back and forth in a vigorous motion. The effect is to push water with the outboard side of' the rudder blade. Dinghy sailors often use this technique to gain steerage in light airs or to move the boat without sails from dock to mooring.

The oar-sculler's stroke is simple in principle, but it is difficult to learn by watching someone do it. Sleight of hand, not easy for a sculler to convey to the watcher, is involved. Basically, the oar is run into the water over the boat's transom, angled outward anddownward about 45 degrees, and pivoted atop the transom. The oar is rotated slightly so that the blade becomes a kind of' diving plane. The loom is pushed against the pivot point so that the depressed edge of' the blade cuts a path through the water, angling toward the stern of a boat on one side. When the limit of the stroke is reached, the blade is rotated so that it dives in the opposite direction. The loom is now pulled against the pivot point until the blade reaches the end of that stroke. The oar is again rotated and the first stroke repeated Since the loom of' the oar is bearing against the boat's stern, the back pres sure oil the blade as it cuts obliquely through the water shoves the stiffly held oar, and the boat itself forward . Simple enough But this whole description reads the same whether one leading edge is utilized, or two. Thus my in frustration in watching Robbie Weatherford sculling without a notch in which to pivot the oar, and possibly your frustration if you've made the effort before We'll get back to it.

Why scull, why not row? Well there are, times when a boatman find himself with only one serviceable oar . At other times there might be neither established rowlocks nor-deck room to swing two oars or a long sweep. The sculler, usually standing to his oarhas a clear view ahead and can maneuver through clustered boats, marsh channels, or ice leads where oar room is lacking on either side. The sculler call propel his boat ahead or astern by simply reversing his stroke while standing in the same posture if his oar notch has beenclosed with restraint at the top. He can spin the boat around within itsown length. He call move it sideways if he positions his oar over the side amidships. The sculling oar, like the canoe paddle, is a water lancet that offers tremendous potential for thosewho can exercise skill. With a suitable oar you can propel a dinghy , a motorboat ,a gondola, a barge, a junk, a schooner. It's all been done to practical advantage, somewhere in the world.

Is sculling faster than rowing? For most of us, no. However, on one morning several years back, my wife and I were overtaken and passed by the black skipper of' a Bahamian yacht who was sculling a rubber inflatable. Susan and I were double rowing a Banks dory at a reasonable clip. The Bahamian was working his single (plastic!) rowing oar through one of the oar-grommets in the inflatable's side. The thing was moving fast and forward. It wasn't even crabbing. Now, there was skill with an oar. We gaped, as did others.

While Robbie Weatherford made that float gyrate under our feet with his powerful Bahamian sculling stroke, I began to feel the frustration that others have exhibited during my efforts to teach them how to scull at home. Robbie and I both seemed to be doing the same thing: the oar was run into the water and pivoted at the edge of the float while the blade cut a zigzag path toward our feet. His oar stayed put and propelled water vigorously. Mine flopped about on the edge of the float, and the blade stayed pretty much where I'd run it in. I longed for a deep notch, all oarlock, tholepin, or even a lashing over the oar at the edge of' the float to show this old man that I could really do it.

Clearly it was he bottom of a notch that was important to Robbie's way of sculling. I needed a deep notch with sides. Susan and I were home from the Bahamas it dawned on me what the distinction was, and why it had been too obvious to be seen that day. The distinction is this. Robbie's Bahamian oar operated like a double edged sword being wielded side to side in a shallow falling-leaf pattern. Both edges of the blade were alternately the leading edge as the oar- cut the water- back and forth. The flat of the blade was essentially horizontal, with the leading edge depressed slightly to make it dive as the oar moved in that direction. At the end of the zig stroke, Robbie rotated the loom just slightly to depress the opposite edge to make it dive oil the zag stroke. His effort, if any, seemed to be in pressing the loom downward on his side of the pivot point so that the upper side of the blade pushed water away from us in the course of each cutting stroke. With Robbie pressing downward on the grip, at one end of the oar, and with water- pressing down on the flat of the blade at the other, the middle of the loom stayed right where it was on the edge of the float despite the tweaking and rotating that made the stroke work. Had he been in a boat instead of on a moored float, the oar would have driven the boat forward instead of pushing water astern. As the boat's speed increased, Robbie would have added more and more angle to the diving edge of the oar so that it steepened the path of the zigs and the zags. If he didn't, the oar would float up or. he would have to increase the frequency of strokes in order to keep up with the moving boat.

The Bahamian sculling stroke, as show me by Robbie Weatherford is a falling-leaf Pattern with the blade cutting both ways in a horizontal stroke. It is a powerful stroke, not tiring and well suited for long-haul propulsion. The sculling stroke that I'd grown up with looked about the same but was very different in its effect. Here the oar is operated like a single-edged knife cutting a downward, slalom pattern in the surface of the water. There is only one leading edge employed. The flat of the blade floats vertically in the manner of a steering oar, which it essentially is, in this form of sculling. For a power- stroke, the oar is rotated slightly so that the lower- leading edge can be slashed across the stern in one direction, rotated back, and slashed the other way. The blade is given considerable twist (toward horizontal) at the outset of the stroke when the boat is stopped or moving slowly, then less and less angle is applied as momentum is gained and the slalom pattern is deepened. At maximum speed about 2 1/2 knots for me in a good skiff, the wagging back and forth has narrowed considerably and the blade remains almost vertical on both left and right strokes. The end result is almost fishtailing with an oar in the manner of the rudder scullers. But you can see why rise of a deep notch is necessary for this vertical or slalom stroke. The sculler's effort is directed as much sideways as downward on the grip of the oar. Without a notch, the loom slips. There are merits to both the vertical and the horizontal scullingstrokes The latter is at more powerful propulsive stroke because the force vector against the water is more directly astern Body weight of the sculler is the main force pressing the loom downward too lever the boat for ward Only at little effort goes into guiding the oar from side to side. Steering is accomplished by loading the oar more on one slash than the other or by giving it more angle to increase side resistance A long oar is highly desirableThe vertical stroke in my hands isbest for a jackrabbit start in still water and it is more responsive for intricate steering through congested areas But it can be more wearing on the sculler over a long pull because arm strength not body weight is the main propellant The fishtailng aspect of the vertical stroke demands side-to-side exertion against the resistance of water. The force vector of each stroke is more diagonally astern today I combine the two strokes The vertical stroke is an excellent "low gear" for underway and for threading the boat through crowded harbors Then I shift to "high", with the horizontal to make speed and distance There are variations but these are the two basic strokes that scullers use.

You also can scull a boat in reverse Its the horizontal stroke falling upward rather than down You'll need a loop or lashing over the oar's loom where it crosses the transom because you'll be lifting the grip rather than pressing I it down to make the blade "climb" astern Tryit. You'll The applauded

In mid-June of 1983 an informal group of sculling enthusiast met at Camden Harbor to try out various kinds of strokes and oars The group was organized by Ben Fuller then curator of the Mystic Seaport Museum who was researching anarticle on sculling for Small Boat Journal The event was hosted by editor Dan Segal and his wife , Judy who had traveled from Vermont to participate. Lance Lee, then director of the Rockport Aprenticeshop gave us a demonstration of Bahamian sculling done with a proper Bahamian oar. Lance had spent much of his boy hood Man O' War Cay, where he'd learned to scull under the critical eye of old Robbie Weatherford and other local fishermen. the oar , lie pointed out was always operated from the port side of the transom allowing the sculler to lean into the oar on one stroke and too pull it back with both hands on the other This placement allows relief of the right hand for fish over the side. A shallow notch wasdesirable. Lance bent to his work with a slow, easy rhythm. He leaned into the oar with both hands on the push stroke; then, thrusting his right arm out horizontally to cause overbalance on that side, he leaned to the right while towing the grip of the oar with his left. The boat he sculled boiled along . He used a straight, thick, narrow-bladed 11' oar .

Dave Jackson of Camden an enthusiastic duck gunner, showed us how the duck hunters scull His boat was a camouflaged fiberglass reproductionof the traditional Merry- Bay gunning "float" with pointed bow, flared sides, and round- bottom. It was fully decked except for a narrow cockpit stretching from about center to nearly all the way aft . The wide transom was pierced on the port side for a tight oar port that accommodated only the looms of his sculling oar. the oar was square lightly fashioned and curved along its whole 7' length so that it arced nearly 3 " upward when laid flat on the ground Dave stretched full length in the cockpit with his head against the headrest on the coaming ,aft, gun (presumably) at right, and the loom of the oar extending into the cockpit over his left shoulder From his prone hidden position Dave could propel the boat quite comfortably by wagging the oar with his right hand in a shallow figure- over his chest. Since the oar was slightly bent it automatically capsized into the proper diving angle of a horizontal sculling stroke each time the loom was reversed with a push or a pull His stroke was rapid, smooth and efficient Steering was accomplished by lengthening the stroke on one side or the other

Ben Fuller's classic 16' wooden Delaware Bay ducker is at slim low-sided half-decked, double-ended boat traditionally meant to be rowed or sailed to the gunning site, then poled close to flocks of birds In a departure from tradition Ben addled a sculling bracket mounted slightly outboard on an exposed crossbeam just abaft the cockpit coaming This boat could be sculled right or left-handed with a bent oar from at lying down position Or it could be sculled while sitting kneeling or standing to a straight oar in either a horizontal or vertical stroke The sculling/rowing/ sailing (and paddling) capabilities of Ben's boat are plain delights to anyone who seeks freedom with an oar Lines of this common style of American hunting skiff', circa 1870-85 are in Howard Chapelle's A American Small Sailing Craft . We didn't have a Chesapeake 'slat" too experiment with. Nor was there a waterman to show us how one might be used Tradition has it that they, operate through a V-shaped notch in the stern of' a boat. Ben Fuller who spent curatorial years at the Chesapeake Bay Maritime Museum could not remember seeing a sculling notched indigenous to the slat- e oar and he wondered whether itmight have been worked against alternate Sidles of a protruding stern post The "slat" I've drawn was done from an isolated oar in a photo Itappears to be a long flat stave of wood molded in a straight taper from the tip of the blade to the narrowed grip. I can't tell whether the blade end is ribbed on both sides in the fashion of a Bahamian oar or whether it is ribbed or arced only on the upper side as a yuloh would be. Possibly a knowledgeable reader can tell us The flat, sectioned loom of the "slat" would make this oar a natural for the horizontal sculling stroke However, with a deep-V notch it could be used like a steering oar too with a vertical sculling stroke

No one in our group had operated a Chinese yuloh . Just about everyone was intrigued by the prospect of propelling a large boat with at long bent oar perched atop a pivot and tethered inboard by a lanyard Plenty of photographs have shown Chinese women yulohing lengthy and loaded sampans with abandon Roger Taylor made and used a yuloh as auxiliary power in a 37' skipjack But Roger away that weekend so we made our own a 10footer from a bent oak plank and mounted it on a 14' crab skiff with a trailer-hitch ball for pivot It worked very well so well, in fact that Jim Benson a bystander drove home and returned with a homemade yuloh that he gave us. He'd given up on it, apparently not having fully worked out the pivot for it before find- a buyer for this boat. Sad. With a block attached underneath to receive our trailer ball, it turn out to be a better, wider-blade propeller than the one we had cobbled Our time together was up before there was opportunity to lengthen its loom to try it out on at lobster boat

Despite our amateurish handling of a homemade yuloh in at miniscule craft the thing seem to have real potential for someone who doesn't trust his engine The stroke is easy back and forth with a yank on the lanyard at the end of pass to capsize the oar into the diving angle for the stroke to follow the properly timed yank on the lanyard also gives the blade a bit of a kick outward and upward increasing the power of the stroke considerably Deft steering with a yuloh would require more skill than We developed that day. The yuloh seemed to The an automatic sculling machine that develops a perfect horizontal stroke without any need for skill to keep the oar from sliding.A full discription can be found in G.R.G. Worcester's The Junks and Sampans of the Yangtze River .The authority on Chinese water craft notes it would seem that the junksand indeed many seagoing junks have generally straight yulohswhich is probably the most primitive variety The curved yuloh is more generally found on the rivers the man or womens at the yuloh holds the rope in one hand and with the other works the yuloh too and fro in a circular manner If more than one is at the yuloh the second works the rope while the others work on the loom".

I'm tempted too draw all illustrations for Worcester next paragraph which talks about eight men on the loom and two on the rope the rope-men throw themselves back- wards with great abandon until they lie almost flat on their backs their opposite members doing the same thing bringing them too their feet again But I'll leave this drawing for the, future and show instead how the oar actually worked during our trials at Camden Man Can you imagine a yuloh the size of a small telephone pole being worked this way by your friends en route to an outer island beach party? What a people that wouldA sculling oar with a shaped blade was brought to our Camden sculling meet by Douglas Martin designer and manufacture of ocean rowing craft based at Kittery Maine This oar with an appended upright has one leading edge obviously intended for use in a vertical sculling stroke It was mounted through an oarlock at the end of a slim cross-deck timber much in the fashion of the ducker coati- mounting on Ben Fullers gunning float Those who tried Martins oar said it was efficient and easy to use I don't know whether or not the oar was patented He allowed us to measure it for publication I offer it here in a dimensioned perspectiveBen Fullers subsequent article "Sculling" A Lesson in One Oarsman ship Part 1 appeared in Small Boat Journal No. 45, (1985). It is a clearly written treatise on handling a straight sculling oar in the horizontal vertical and reverse stroke modes Along with this how-to is at good deal of colorful observation of aboriginal sculling in this on that kind of boat as Beth has witnessed it in various parts of the world I must here confess that we coined the words "horizontal", "vertical"' "falling-leaf," and "slalom" as a means to sort out the various ways that sculling oars are handled Part 11 of Ben's article "Sculling Putting Your Best Oar Behind You " appeared in SmallBoat Journal #46(1986). It covered the bent oars of the duckers the yuloh and Doug Martin"s scientific blade Now all that remains is for you to learn to scull if you haven't already. If you have neither boat nor oar, practice the various strokes with your hand in the bathtub Grip your elbow (the pivot point with your other hand while you do it. Go out to a dock. Make a "slat" oar. Try it there. It's fun and who knows, knowledge Of sculling may get you home someday if you find yourself up a creek without a paddle.

Sam Manning learned how to scull when he was eight years old. His stepfather a civil engineer experienced in building harbor works taught him, and Sam's been at it ever since.

Feel free to email me, David Beede simplicityboats

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I have been a recreational sailor for many years, with a particular interest in small sailing craft; therefore much of the content of my 'blog' will be related to this subject.

Friday, November 29, 2013

‘Minnow’s’ Yuloh – Part 3 (Yuloh Links)

The epoxy cured overnight, and this morning I sanded the yuloh’s shaft in preparation for varnishing. I also started sanding the blade to give it a better finish. I’ll paint the lower part of the yuloh.

Until I receive a stainless steel pivot pin from the firm that is manufacturing it, I am reluctant to drill into the shaft to form a cavity for the pivot cup. I shall use the pin to shape a cup in an epoxy base – that is my plan. I’ll coat the rounded end of the pin with grease to prevent it from sticking to the epoxy. The reciprocal pieces should fit together perfectly.

I shall have to devise a means of suspending the pin in the epoxy so that no more than half of the ball is submerged in the epoxy. If that were to happen I would not be able to extract the pin from the cured epoxy without cutting into it.

Links

Wooden Boat NZ Sculling

http://woodenboat.net.nz/Stories/Sculling/scullthree.html

How to Scull a Boat

http://www.simplicityboats.com/ScullYulohaboat.htm

Bing Yuloh Images

http://www.bing.com/images/search?q=boat+yuloh&id=A2EAB6E133DFD7959A722CE5BD12E9E86EED5D10&FORM=IQFRBA

The $10 Yuloh

http://www.simplicityboats.com/yulohpage2.html

Single Oar Sculling

http://www.diy-wood-boat.com/Sculling.html

Yuloh, Zhujiajiao, China

http://www.youtube.com/watch?v=UjyE7dyR2X4

Stevenson Pocket Cruiser under Yuloh

http://www.youtube.com/watch?v=P3pbYMOK8Us

AD-scull. sculling action,deck view

http://www.youtube.com/watch?v=AT0h0gY_JEk

Easy Go Yuloh – Part One

http://www.duckworksmagazine.com/11/howto/yuloh/index.htm

Easy Go Yuloh - Part Two

http://www.duckworksmagazine.com/11/howto/yuloh/index2.htm

Cranks with Planks

http://freepages.genealogy.rootsweb.ancestry.com/~fassitt/cranks/cranky_sampans.html

Yuloh – Dave’s Wiki

https://aiki.pbworks.com/w/page/1594891/Yuloh

Collars – The Yuloh Sculling Oar

http://www.collars.co.uk/site/scripts/documents_info.php?documentID=32

Yuloh Design Cycles

http://timesupboatingassociation.wordpress.com/2011/08/24/yuloh-design-cycles/

Sailing Auklet – The Yuloh

http://sailingauklet.com/2013/10/13/the-yuloh/

Posted by William Serjeant at 9:06 pm

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4 comments:

Brian said...

Lovely picture of a Paradox and nice article about sailing her. Just to spur you on!http://smallcraftadvisor.com/our-blog/?p=4119
10:04 pm

William Serjeant said...

Thank you Brian,
Sean's blog is a favourite of mine. I am inspired by what he is doing with 'Scout'.
Cheers,
Bill.
11:17 pm

Sean Mulligan said...

Bill....first you are way to complimentary....thank you for that...please know the feeling is mutual. :-)

Fantastic amount of information on this post on Yuloh's...thanks for compiling all that. I am about to make some mods to my own as we got the shape of the foil on the blade reversed from the way it is supposed to be. It works and I am getting the hang of it, but I suspect I can make it much more efficient if I get that foil corrected.

Minnow is looking outstanding! Keep up the good work!!

S
4:11 am

Steve Carey said...

From one of your links Bill, I found this wonderful video. Love the way that his sculling oar dobles as his rudder!

http://www.youtube.com/watch?v=y-G_StsC3zo

Steve
12:10 pm

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A Depth Sounder for 'Minnow'

‘Minnow’s’ Yuloh – Part 3 (Yuloh Links)

‘Minnow’s’ Yuloh – Part 2

‘Minnow’s’ Yuloh

'Minnow's' Outboard Bracket

Fitting ‘Minnow’s’ Autohelm 800.

Identity and Fulfilment

A little more done on 'Minnow'

Varnishing ‘Minnow’s’ Autohelm Supports etc

Solution for ‘Minnow’s’ Autohelm

Satisfying Afternoon with ‘Minnow’

Better Progress with ‘Minnow’

Accomplished Something with ‘Minnow’

Major Distractions from 'Minnow' - Part 2

Major Distractions from ‘Minnow’

‘Minnow’s’ Autohelm – Part 2

‘Minnow’s’ Autohelm

Electrics for ‘Minnow’ – Part 3

Electrics for ‘Minnow’ – Part 2

Electrics for 'Minnow'

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‘Minnow’ on her Trailer

'Minnow's' Anchors and Trailer

'Minnow's' Steering Gear

'Minnow's' Road Trailer Again

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Something Done on ‘Minnow’

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Bill's Log

Friday, November 29, 2013

‘Minnow’s’ Yuloh – Part 3 (Yuloh Links)

4 comments:

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	Apply glue and clamp. The wedge you cut off earlier will give you a parallel clamping surface. Since I was going to use mine before the glue had fully cured I also used four 1 1/2" galvanized deck screws. I used PL Premium glue because I like it so much, but I'm pretty sure Titebond II would work as well.
	Here's a look at the wear that resulted from just a few minutes of sculling with the first pin attempt without the poly butyl tubing. It chewed up the cap edges pretty quickly. I counted on the plastic pipe caps to be expendable and easily replaced, but not with every use!
	Here is the pin and cap ready for use. The pin is a 6" by 3/8" carriage bold with a short piece of 1/2" polybutyl tubing held in place with a washer and nut. This both limits wear of the cap edges and limits the side to side travel or tilt of the pin in the cap. That in turn limits the feathering of the yuyloh.The cap is inset in a 1/4" deep hole the diameter of the cap. It's held in place with a galv. deck screw, that is countersunk into the inside of the cap.