Simple habits, simple boat

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.

CLICK ON THE PICTURES TO MAKE THEM BIGGER
To make the rig adaptable to every wind condition she carries plenty of spars: one topp mast, two light wind booms, two hard wind booms one sprit and one big yuloh to be used when there is no wind. If I had them on deck there would be no place for things like solar panels. I carry them below deck in carbon tubes. The picture below shows the holes where the spars will enter.
This arrangement has the advantages of lowering the center of gravity and reducinging wind resistance. The spars and the mast are easily accessible from the main hatch. I dont have to go on deck to adapt the rig.

The picture below shows the spars in the main cabin, the bed room. The two vertical struts support the deck beam.

The forward ends of the tubes drain overboard. Here I am building up a support of aluminum netting for the glass fiber which will connec the tubes to the drains.

The hinge is for the aft opening window in the deckhouse. Below is a picture of how I made a mock up of the window.

Below the window mock up is in place in the open position.

Below the window mock up is in place in its closed position.

Below is a close up of the hinge which makes possible angular and linear movements. It is important to have a linear movement in a window when you clamp it down. Ordinary hinges, in my opinion is no good. Still they are used by nearly every one. The reason why the are not always leak proof is you can only clamp down one side of the window, the side opposite to the hinge.
The thousand old trick of making a hinge of a rope threaded in a eight figure gives enough play to move the windows edge deep into the gasket. Making it non leaking in all conditions.

On Saturday 5 Dec 2009 Mattias visited me. He is a professional balance adjuster. Here he is adjusting my balance I use for epoxy. My balance is now accurate to a tenth of a gram. I feel that if I can do my best on land, my chances to succeed at see will be bigger. I also always pour the epoxy in a second container after having mixed it.
Mattias has is interested in small boats and have bought plans for an Paradox a Matt Layden design.
Paradoxes are slowly spreading from Patagonia to northern Norway.

The bowboard daggertype did not slide up and down to my satisfaction.

I made a new board rotating around an axis. However the line arrangement became to complicated to my taste. I wanted to be able to chance the lines at sea.

Next idea to keep the bow into the wind, making her nicely fore-reach in a storm was to have a mizzen on the rudderpost and sheated to the rudder like the Thames barges a hundred years ago.

However being modern I wanted to make a solid rotating wing-sail using a VX40 rudder. Even that turned out to have its problems, but if at first you do not succeed, try again.

The final theory is to lean the mast to lee. That will give the boat weather helm, creating the same effect as a bowboard or a mizzen but much simpler.
The above picture shows a mock up of the strut giving the mast additional support in storms. The tilting angle is 30 degrees. In addition I have the shrouds.

At the moment I am repairing the damage I have done to the boat. Taking away the case for the bowboard and filling up the big hole.

Thanks to the ingenuity of Beppe my web master my blogg now seems to work. Apparently there are a thing called html which somehow showed itself instead of the picture.

The above is the sides of my centerboard case the inside surfaces difficult to reach on the finished boat i have therefore sprinkled them with copper powder to make them antifouling. As copperpowder solves not well i epoxy i have put peelply on top. After tearing it away one gets a nice smooth surface. It is also good for the underwater part of the hull.
Greatings from Yrvind back in business.

This is line tensioner is for the jib. I have redesigned the rig. There is no longer a forespar nor a stay for the jib to be hankt on to instead its leading edge is made of spectra or dynema and tensioned. Hence the winch.
It gives a very big force fore its size and weight and need no servicing
An other great advantage is because the standing part is made of carbon it can be laminated to the deck spreading out the load on the sandwich construction

Unfortunately the software to this blog still does not work. This has been written blindly. When it works properly I will write more.

Bamboo can grow 121cm 47,6 inches in a 24 hour period with one hour burst of speed more than one meter. That is a world record and impressively fast. But my my boat will be much faster. She may average 3 knots or 133344 meter in 24 hour. But that is slow compared to a airplane which crosses oceans i a few hours. However the sense of speed of bamboo growth or my boats speed is big and that is one of the reasons why it is not boring to spend months at sea in her.

Body and mind is one.
A small boat gives a healthy body.
A healthy body gives a healthy mind.
A big boat gives comfort, but comfort makes you fat and bored.

WHEN WILL IT BE READY? THIS IS THE MOST FREQUENTLY ASKED QUESTION.

Good work is the determining variable not time. I like doing good work. I dislike haste. Therefore when not proud of what I have done I redo it until I am satisfied. Dogged does it, and one day the boat will be ready, but when I do not know and to me it is not important because I do enjoy building her.