November 27, 2012


The complexity of real life always guaranties an other solution. Looking at my mock-up I realized that I could make a better rudder arrangement. Seeing Marströms catamarans with their connecting bars for seven years I took it for granted that twin rudders needed a connecting bar.

One is blinded by preconceptions and hidden assumptions. This is not the first time. For example 1968 I bought an old wreck, named her Duga intending to do as Captain Joshua Slocum converting her into a world cruiser.

Below: Duga as a wreck. She was built 1885 as an steam launch. Click once or twice to enlarge.

I sailed Duga to Rio de Janeiro Brazil 1969 – 70. She was later sold in Florida. I rigged her as an staysail schooner. To prevent her making leeway I gave her a daggerboard. She sailed well.

Later Duga in the Bahamas under US ownership

Duga had her rudder post inboard. I gave her wheel steering and placed the quadrant behind the rudderpost as I had seen on other boats.

1971 I started to build Bris. She was a double ender. I had been happy with the wheel steering. Problem was the rudderpost was now at the stern, the very aft part of the boat. The problem was easily solved by a stainless pipe construction for the wire blocks to give them required distance from the quadrant. I sailed her happy for many years

A map showing some of Bris passages. Later I sailed her to Newport RI where I donated her to the Museum of Yachting.

Bris in Mar del Plata Argentina with a girl freind. The stainless pipe construction holding the blocks for the steering arrangement can be seen. Click once or twice on the picture to enlarge.

Then one day many years later back in Sweden standing musingly looking at her I realized that I could have turned the quadrant 180 degrees and would not have needed the stainless pipe construction, that although had worked fine had been unnecessary and a worry in ports being fragile compared to the rest of the boat.

One is blinded by preconceptions and hidden assumptions.

Now as I was looking at my mock-up I realized that if I bent the tillers toward each other I did not need the telescopic connecting bar the universal joints and all that. The bending would put the tiller more to the center and I would get the needed distance between the quadrant and the steering blocks. The rudders would then move in parallel by holding two two leeward pulling lines together on one side and the two windward pulling lines together on the other side. When I liked to use the rudder as sea-anchor the steering ropes would let me be able to put them in V-position acting as brakes.

Pictures below. If you do not follow I have not expressed myself clear enough and more will follow.

Do I spend to much time solving problems? No – nothing is as much fun as solving problems. By evolution man is a survival machine. The Swedish lifestile means that the gouverment solves all your problems and in exchange you are a slave working to make the economy grow. The idea is that entertainment and comfort shall make you happy. Most people spend their life waiting for something. My planned voyage is a thing to hang up problem solving on. It creates a problem rich environment. That will help me to reach the higher spheres of happiness. The voyage has already started. Planning designing building and sailing is not to be seperated.

To be continued…

Regards Yrvind.

November 26, 2012


Although a deep-water sailor i prefer kick-up rudders. Flotsam and jetsam may damage a fixed rudder. Attaching the rudder-blade to the rudder-head should be given some thought. Traditionally it is sandwiched in a slot much like the blade of a folding knife. There are some disadvantages to this method. The blade cannot be lifted more than 90 degrees. That is good enough to sail in shallow water but in port it sticks out and is easily damaged by other craft. Then there is the question of play. If given to much play the steering becomes imprecise going downwind. If given to little the rudder jams in its slot. The most difficult material to use is wood because it swells and shrinks.

A more modern way pioneered by Bolger and others is to clamp  the pieces together using one bolt. At first it looks week but an analyze shows that it is strong. It is not equally strong on each tack but nearly so and strong enough. It is a simpler and lighter method and by adjusting the nut on the bolt you get just the right kind of play and friction. Also the rudder can be raised 180 degrees, an advantage in port. That is the method I use today.

The rudder mock-up now has kick-up rudder. the below picture show one rudder-blade attached in down position. Thanks to the platform I do not need ropes to raise the rudder-blade. It can be done by hand.

The picture below shows the rudder in up-position. Click once or twice to enlarge.

The picture below shows the same thing from the other side.

On wendsday I go to Gävle to give a talk to SXK -eggesundskretsen. I do hope the do not have a blizzard. Thursday I will be in Örebro to give a talk to Sweboat. Friday I be i Trollhättan to my dentist. There i will also visit my freind the ultra-distans runner Rune Larsson who gives me inspiration for endurance undertakings. Rune has won the Spartathlon three times. He has run across the US. He has rowed the Atlantic. He run 262.4 kilometer in 24 hours.

Rune and me running

Thanking Rune

To be continued…

Regards Yrvind.

November 25, 2012


Today I completed one more ½ scale rudder mock up. It was elucidating. When playing with it I noticed that the connecting bar kept the rudders parallel to each other only when they were aligned close to the boats centerline. At bigger angles the lee rudder turned more. At Marström I have seen plenty of M20 and M32:s Rudders mowing in parallel thanks to the connecting bar. Why did mine not do so? Simple, M20 and M32:s rudder axis are parallel. My rudder axes are not vertical. They are angled outward and back.

When you do something new you always get it wrong the first time. You are a child in a new world. Why, because real life is to complicate to be imagined. Even the combination of a small number of elements gives many possibilities. Six persons can be placed in 720 different ways around a table. With six people one can have a different setting around a table each day for two years. With 24 persons the combinations increase to six times ten to the power of twenty-three. This is remarkable because even if you change settings a thousand times a second you have to continue a thousand times longer than our universe has existed. A boat contains many more elements than twenty-four. That guaranties that there are always new possibilities – and new ways of making mistakes. That is why I spend much time on making mock-ups and why building this boat takes longer than building one a conventional one with drawings from a yacht designer. But of course it is so much more fun and instructive.

Going about one push the rudder to lee. With this rudder arrangement the lee rudder will turn more than the windward on. Does it matter? If it had been wheels on a car and you were concerned with the Ackermann steering geometry and all that – Yeas. But rudders are not wheels. The rudder force is proportional to area and angle of attack. Both rudders give turning moment. If they are not equally big I do not mind.

Why do I have a connecting bar? Answer – it gives a simpler line arrangement and both rudders turn at the same time.

Below are illustrating pictures.

Aligning the hinges with the help of a ruler.

The mock-up seen from behind.

Seen from above standing on my ladder.

Seen from abouve standing on the workbench.

To be continued…

Regards Yrvind.

November 24, 2012



The bronze shoes serve several functions.

They act as ground plates for the lightning conducting system. There is one sole directly below each mast, one at the port bilge and one at the starboard bilge.

I use a high tin alloy for strength. Being located between the bottom and the sides of the hull they protect the boat from chafe and make her bottom so strong that she can be dragged over concrete and rocks when handling her on land. Taking the ground will therefore be made with less worry.

The soles are mirror images of each other therefore I had to make two molds luckily I got their volumes very close the weight of the two soles differ by only 0.5 %. Their weights are 52.8 and 53.1 kilos respectively, totaling 105.9 kilos. They lower the center of gravity and acts as ballast. 12 % tin-bronze has a density of about 8.8. Lead with a density of 11.3 is heavier. Cast iron with a density of 7.2 is lighter.

Containing 88 % cupper they are antifouling a good thing when chafe wears away the bottom paint.

Bronze is the most expensive of these alternatives but its many other advantages made it a natural choice for me that always strive for perfection. However only comparing the price of bronze and lead would be wrong as there are many consumables and handling costs like making the patterns mold the work at the foundry and transport that would be the same. These soles will keep for thousands of years and may be an enigma to future archeologists.

Below are pictures. Click once or twice to enlarge.

To be continued…

Regards Yrvind.

November 19, 2012


YRVIND-TEN will hopefully be propulsed by three different kinds of forces, wind power muscle power and wave power. Here I will discuss wave power.

Whalers had observed that a dead whale floating on the surface sometimes made about one knot of speed due to wave action on the fluke. It is said that some of the seamen being of the lazy kind cut of a fluke and fastened it under their boat that they did have to row. Haven’t been there myself at the time I do not give my guarantee for the truth the above.

What is true and documented and still exists is a boat that was built in 1895 in Neaples Italy by Herman Linden. He worked at the Zoological Institute. He was watching the fishes and especially the dolphins as the moved by moving their tails. Somehow he got the idea to put a fin under a boat and get it to move with the help of wave power. He named the boat Autonaut because it moved by itself. The boat was 4 meter long and had a beam of 90 centimeter. The weight was 200 kilo. The weight of the fins was 40 kilos and part of the ballast. To everyone’s surprise it worked very well it made 3 – 4 knots of speed against the waves.

Many more boats was built and experimented with during the following years.

Einar Jakobsen was one of the experimenters. He had observed that a wooden board released from underwater was not floating straight up but gliding upwards at an angle. That gave him the idea. 1977 after some practical experiments did he build a foil that converted 80 % of the wave energy into propulsion. His foil hinged on an axis. Elastic spring regulated the angle of attack. A BBC TV-team filmed his boat making 6 knots against the wind. There is a lot of energy in the sea, on the average about 100-horse power per front meter. But then of course you have to leave flat water behind you.

In 2008 Japanese yachtsman Kenichi Horie wave powered his catamaran from Hawaii to Japan. The journey took 110 days.

Wave propulsion has seen a lot of promises and a lot of setbacks. The problem is, grownups always want bigger and bigger things. Some things are intended for small things. Galileo was the first one to scientifically explain why scaling up a small successful idea does not work. Among engineers it is called the square cube law. If you double the scale of a structure the surfaces increase by the square that is four times but the volumes increases by the cube that is eight times. The strength is in proportion to surfaces load is in proportion to weight. That explains a lot of things among other why small things are stronger than bigger ones. That is why it easy to build a short bridge and why it becomes more and more difficult the longer they get.  It explains why birds only grow to about ten feet wingspan. It explains why a wave-propelled boat is better being small.

If you are small you can get away with things that are impossible for big creatures. Some small spiders spin a thread when they feel like traveling. The thread being light is caught by the wind. When the spider judges it long enough he lets go of the ground and flies to his desired destination. To land he eats up his thread, recycling it. It is protein after all. Being small he has a happy landing. He has been flying without using non-replaceable fossil fuels. Lets do like the small spider and not like the grownups. Like what is small and natural. Support small projects.

At the moment I am trying to integrate wave power propulsion in the YRVIND-TENs rudder system. I have some good ideas but there is as usual some interference with other functions. Nothing is as much fun as solving problems.

To be continued…

Regards Yrvind.

November 17, 2012


YRVIND-TEN has two rudders. They are angled outwards 20 degrees and backwards 20 degrees. They pivot (not shown in the modell) as not to break if hitting ice or taking the ground. Each rudder has a top and a bottom bearing. Between them is the tiller or arm. A rod connects the two rudders via the arms. The connecting rod is telescopic. ( not shown)The reason is that in strong following winds each rudder can be angled outwards by shortening the connecting rod. This has a bit the same effect as a drogue. It slows the boat down and make it directional stable. If the boat deviates from it downward course the lee rudder gets a bigger angle of attack while the windward rudder will get less angle of attack. The resulting force will restore the boat to its downwind track.

The steering is done with ropes. Tackles (not shown) provide the correct power ratio.

The bottom bearings is fastened to platform close to the water handy when getting in and out of the water. I intend to swim every day if the weather is not to bad. That will contribute to keep me fit. There is a step on each rudder.

This platform makes it easy to raise and lower the rudders. Hopefully I will develop a water generator that fit the lower part of the rudder, likewise a foil that with the help of wave power propels the boat in calms.

The pictures below show the first model. The scale is 1:2. The real product will be bolted to the transom with four screws. The model is very rough, not more than a mock up and many details are not included. If the concept is difficult to grasp blame me. Better models and explanations will be shown in course of the building.

The connecting rod and the stearing ropes can be seen where the plywood is screved to the particle board.  That position is chosen so that it will not interfere with me getting in and out of the water. I have used pieces from my scrap pile. the big round hole has nothing to do with this project.

In the picture below the stearing lines can be seen crossing each other on the transom. The crossing is to make the boat stear the conventional way. One can also re-learn. I chose to go conventional. Not everyone does. A freind of mine reads upside down. He learnt to read himself at a young age by looking at his fathers newspapers across the breacfast table. He can also read the conventional way. Click on the pictures once or twice to enlarge them.

ADDENDUM Sunday 18 Nov 2012

After sleeping on it I realsise that if I add one more sheave to the block fastened to the connecting bar the ropes do not have to cross each other. That will be a neater solution.

To be continued…

Regards Yrvind.

November 16, 2012


Here is the beginning of my bunk. Becouse much of the sailing will be done in the winter using no heater and no fossil feul I will do plenty of insulating. The hull thanks to the sandwich construktion and Divinycell gives in itself excellent insulation. Still there will be many months of winter sailing therefore inside that insulated hull is an insulated box that is my bunk.

The first step is shown fixing the position of the aft side. I use four sticks of equal lenght to get the planes parralell.

The below picture show how I have have attached the bunkside with epoxy filler. When it sets I will remove the sticks and the clamps to get better acces.

To be continued…

Regards Yrvind.

November 15, 2012


When building a small boat, deep clamps are good to have. When my former small boat laboratory was illegaly attacked by the oil company (It was situated right on top the worlds lagerst stock pile of oil, 2.7 million cubik meters which they now intended to use. The stock pile was originally intended to be used in the eventuell war against the Sowjet Union, now the oil company planned to use my land. Only problem was my lack of respect for big buisness )  I won the battle but  lost a lot of tools and had to mowe to the other side of Sweden.

To expose the oil companys illigel action I had made a counter attack on their head quarter using smoke grenades in front of most of the Swedish news media including four TV-teams

The alarm went, the police was on its way the companys security force seized me

Minutes later the CEO was informed. Of course the last ones he wanted on the place was the police that would have taken the case to court and exposed there criminal activity even more. They police were ordered back and I released. The action topped the Swedish news that day. I won the battle but the locals did get angry they lost a lot of emplyment and I had to leave town a half finished boat and most of my tools. In my book Konstruktören you can find a chapter dealing with the episode.

Just a few weeks ago I replaced two of the lost 50 cm ( 20 inches ) deep clamps. Today I needed one of them. I was setting the lids of the Yrvind-cleats in bedding compound but could not get enough pressure on them to make it flow. I had tried with my hand I had used the stronger muscles of my leg to give my foot enough pressure on them, to no effect. Finally with the help of the heavy deep clamps it went easy as butter. I was pleased.

By clicking twice on the picture you may just see a bit of black bedding compound beind squized out.

To bee continued…

Regards Yrvind.

November 14, 2012


I now have a phone that can take pictures. Just for fun I put a 1:10 scale model of myself on the spreader. There are two stepps on each mast in addition to the 30 cm high deckshouse that is not on the mock-up modell.

I like to climb things and it will be a lot of fun to run up in the mast and have a look around now and then. It will also give me some excersice.

To be continued…

Regards Yrvind.

November 12, 2012


600 days of nonstop sailing, mostly in the southern ocean will very likely expose us to strong winds. Although I will endeavor to make the masts sturdy it will be nice to have a simple way to increase their strengths.

The following pictures shows one way of doing that. I will place a horizontal strut between the masts at about half their height. The strut can also be used for exercises and lookout. From the strut where it connects to the masts Dynema ropes extend down to the deck, to strongpoints, my Yrvind-cleats acting as super-strong chainplates. The shroud angles are never less than 26 degrees. Half that angle 13 degrees is ample. The haliard is now down to half the mast hight. This reduceses the compression and bending appreciably.

I do not think it will take long to set it up, especially after getting some practice. The masts are very close to the hatch and with one mast on each side the operating area will be very steady.

The below pictures shows a one to ten scale mock up of the idea. The first picture shows the port side of the model slightly from foreward with the wind in from foreward.

The second picture show the boat with the wind from starbord slightly from behind on the same tack.

The below picture shows the model going downwind. The nice thing about the balanced lug sail is that the downhaul can be mowed. The sail is not attached to the mast. In this scenario the dawnhaul is on the Yrvind-cleat on the bow on the starbord side. I all of the pictures the sail on tha other mast is rolled into its casset and lashed to the deck.

The last picture shows the same set up but from behind-

To be continued…

Regards Yrvind.

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