The vertical subdivisions behind the side panels are now done.There are four on each side in the fore cabin and the same amount in the aft cabin. I have now also begun work on the shelves. There are nine lockers on each side in the fore cabin and six on each side in the aft cabin, a total of thirty. There are more than three hundred liters of stowage for books and food. There are also eight water jugs under the aft deck, five liters each, four on each side. They are connected to my water catchment system. A small slow boat on a long voyage needs a lot of secure stowage.
Below is a picture of the fore cabin. At the bottom of the picture on the starboard side can be seen the shelves, the horizontal division of the storage space, coming up.
Below is one of the shelves. The clamps hold iron angels which the shelves rest on. the lead piece holds the shelf in place while the fillets cure.
Before this was done I had made the lead chambers here is the six ones on the starboard side. There is a total of eighteen. At this moment the lead weights is being poured at Blomstermåla foundry. More about that later. Each weight is 14 kilos or about 31 pounds
My heavy weather ventilation system.
First I put in the two bulkheads.
The ventilation channels are built on the main bulkhead.
I wish I could draw as well as Matt. As it is you have to do with this. The top picture show the boat on even keel healing 0 degrees. The air comes in from the deck and is ducted in an L-shaped channel down and across the boat.
The middle picture shows the boat heeled 90 degrees. Part of the deck and one ventilator then comes under water. It flows down the channel, but the bottom part of the L is now vertical and the water gets no further.
The bottom picture shows the boat healed 180 degrees. Now the first part of the channel is vertical preventing water from entering the cabin.
This is the fundamental theory. However as air not only have to enter but also leave the cabin two sets of channels is necessary. Also to get distribution of the air the entry and outlet have to be as far away from each other as is practical. Therefore the second channel is an L with an added bend making it an U. With this arrangement air can enter at the bottom of the boat and leave at the top or vice verse. This demands a drain in the bottom of the U were water can be let out in the bilge after an capsize. I use two small carbon pipes.
As there is plenty of wind pressure in a gale my channels have a small section 3 by 4 centimeter roughly equivalent to 1 by 2 inches. Still they are much bigger than my nostrils.
I build the channels of 1 cm divinycell which I edgeglue to the bulkhead.
When the first U is done I do the second L. The also function as a seat.
Here the system is seen from above. When the deck house is built I will continue the channels to the top of it.
Here is a view from below. The two black carbon drainers can be seen.
Below can be seen the side panels getting fitted. I sleep on the floor in the forward part of the boat. The read containers are NM-epoxy, but I use them as mock up for water containers donated by Mellerud Plast.
Below is the sleeping room. The lead chambers can be seen at the bottom the other openings are for stowage. The top of the plywood side panel is reinforced with a U-profile in carbon. It contains handhold’s which also serve to fasten my safety belts into. All the black stuff is carbon prepreg cured in Marströms big autoclaves. Thanks to Göran and Pers kindness I have the full run of their workshop.
Below is the aft part of the boat. There I will have a nice seat and big windows to give me a good look at all the interesting things outside the boat. At the forward end is the ventilation channels.
The side panels fits snugly into the ventilation channels. With an epoxy fillet and some fiberglass I get a strong bound.
Below the the stowage hatches gets a coat of epoxy to seal the plywood. Note that the top of my home made work bench is made of a one inch thick steel plate.
Below, last but not least, me and Göran Marström in fromt of the big autoklaves. Thank you Göran for all the help.
Yrvind ½ has 18 lead chambers. They are placed in three groups, six chambers in each group. They are situated to port and starboard and aft close to the transom.
The ones to port and starboard helps to control healing. In strong winds, to get more righting moment, six lead weights, each 15 kilos or 33 pounds can be shifted to windward, either all or some of them. In light wind, to dig in the chine runners deeper the weights may be kept to leeward.
The aft group is useful when running before gales with breaking waves. Weight placed so far back moves the center of resistance aft and makes the boat more course stable. Also as the mass moment of inertia increases with the square of the gyr radius the boat will much better resist pitch pooling. Naturally it will also be more easily pooped, but as the boat is strong and waterproof it is in my case a better choice.
The above picture shows the lead weights placed to windward. As can be seen, so placed they give a greater righting arm compared to, if the same wight in the form of a 200 pound man would have been placed on the rail.
This is how the starboard lead chambers look. (later I will add lockers on top of them)
Lifting the lid one can see one mock up weight with a wedge on top of it. When moving the weights from side to side they slide across the floor up on a wedge an fall down behind it. Then another wedge is jammed in filling the gap to the roof. After that a small door is closed keeping the wedge in place. Now they can not get anywhere even if the boat is capsized or pitch pooled.
The wedge which is placed on top of the weights.
A mock up of one of the 15 kilo lead weights with its stainless steel handle.
The door which keeps the wedges in place.
On its back can be seen the locking mechanism which keeps the door in its place
Its made of a piston hank. The pieces which holds the sail and attach it to the stay is cut of with a hacksaw. A piece of string is attach to the nob to easier get a grip on the piston.
I use these piston hanks to lock many lockers.
1985 designed and built Matt SWAMP THING 4m long 1.08 beam 19 cm draft with a cruising weight of 400 kilos she was the first boat to have chinerunners. Other boats based on the same concept is PARADOX and ENIGMA.
I consider it the most important innovation for small boats during the 20th century.
Here is PARADOX chinerunner.
Here is Matt with ENIGMA.
Here is a close up at ENIGMAS chinerunner.
This is how Matt did ENIGMAs chinerunner,
YRVIND ½ is a composite boat so I use a different technice.
First I attach plywood pieces insulated against epoxy with packing tape.
To them I clamp a glass fibre sheet. I fasten it to the hull with a fillet.
Now this shelf is ready to recieve several layers of glass fibre. As they are exposed I make them strong about 20 mm thick or about three quarter of an inch.
When i take the boat outside I will grind it to a nice shape.
Here is a drawing Matt made for a bigger boat.
The chinerunner concept looks simple, but dont fool yourself into thinking that they are just add ons. The idea of preventing leeway with the help of chinerunners, like most successful fluid flow devices, including the bumble bee, is a sophisticated concept. Matt is also taking help of the the lifting body concept and a large rudder.
The boat have to be relatively heavy to sink deep enough in the water, but small cruisers are not light. The ratio beam to draft has to fall within a narrow range. PARADOX beam is 1.23 m her draft is 0.23 m. YRVIND ½ has a beam of 1.3m and a draft of 0.22m
The concept gives shallow draft with no moving parts. The hull-shape gives a lot of stability as it like the catamaran quickly moves a lot of buoyancy to lee for a small angle of heel. It also gives a lot of flat floor on the inside, welcome on a small boat. It is also a hull-shape easy to build. Almost to good to be true. Strange that not more people take advantage of this windfall which has been around for quarter of a century.
Archimedes said, “Give me a long enough lever and a fixed point and I can move the earth”. Like Archimedes I like strong points. There should be attachment points on a boat not only strong enough to lift the boat, but also they should be able to withstand dynamic loads.
These points of attachment where my first job on the new hull.
To make them really strong I decided to join the outer and inner laminations. Normally there is no problem of pealing away a bit of lamination, but to my joy the combination of the NM-epoxy and the new 100 kilo Divinycell gave me a lot of problem. After cutting the inner laminate with a diamond saw I put in a chisel to bend it away, but it did not budge, so in went another chisel. No progress. I put in a third chisel hammering on the different ones alternativly to no anvil. Finally after adding two big screwdrivers did I get the piece away. It had taken a lot of work but I was happy of this strenght demonstration from my new boat.
I included apiece of stainless pipe on each side to protect the hull from chafe.
Here they can be seen from the outside.
This is my fitting 30 mm stainless steel 2 mm thick with two pieces welded on to prevent the rope from sliding up or down. To hold it in place while gluing it to the boat I temporarily attached it to a piece of plywood.
Here it is in position.
Whit the help of a bit of a plastic bottle I created a form. Now I can laminate from the inside and get a new inner laminate with a the necesary distance from the stainless pipe to give place for the rope. When that is done I cut the outside skin and inside this created cave lives my point of attachment. I made one on each side of the transom and one in the stem. Now I can turn my boat into any desired position while building her. And of course later when cruising they are invaluable.
Here they are seen with ropes attached to them. By the way, the weight of the hull came out to 150 kilos.
After getting the frames out, getting a fillet in corners, reinforcing the stem with a few layers of glassfibre and getting her nice and smouth she was ready to be sheated on the inside.
First however I could not resist the temptation to enter her and get a feeling of the size of my future home. I found her huge, here was plenty of space. I was happy I had not made her bigger.
Four people had promised to help. Unfortunatly two of them could at the last moment not come. I and the two brave ones decided to go ahead anyway. It became a very long day. We started 9 in the morning and were done 1 the following night after 16 houers of backbending work.
Here we start cowering her with NM-Epoxy.
Here the first of the two layers glass fibre comes on.
Next day I was happy to see that the work had been very succesfull.
When the big pieces of Divinycell were on place it was time to fill out small holes like here in the foreward part
or even smaller ones were plugged, here Im doing the holes were the screws holding the Divinycell to the frames had been.
After that it was time to shape the thick Divinycell.
I have found a good quality kitchen knife sharpened to a racors edge to be very efficient.
Checking frequently with a pattern of the desired radius.
That done it was time for sanding with the longboard
Finally her shape was to my satisfaction.
Now it was time for freinds to help me with the lamination.
It was Jonas and Ingrid who came from the west coast and Anders and Eva from Västervik. We started 9 am and finished 8 pm. Thank you my freinds.
We used NM-Epoxi and quadrupel-axial glass fibre, 600 gram per square meter. On the hullsides we laid three layers. The middle of the bottom got the most layers 14 + 3 unidirectional going from stem to stern. I wanted the bottom of my boat to be strong when drying out and when landing on beaches. We finished with peel ply.
Here am I the next day happy that everything had gone well.
After peeling of the peel ply it was time to turn her over that I could start on the inside.
Luckily there were some steel beams in the roof to attach the lifting equippment to. Even more lycky they were spaced 2.4 meter and the boat is 4.8 so I got one beam in each end.
Whith the boat on its side I took away the fundament to make a flat flour.
Then I started to take away the frames. To be continued.
Covering a small boat in Divinycell is mostly nice and easy work. Progress is quick. When the moulds are upp small pices of wood are scruved on to get grips for clamps and screvs. Then everything is sheated with plastic film to work as a release agent to avoid the epoxy to glue the Divinycell to the frames.
I used a roll of hewy paper to get the shape of the panels.
On the flour I cut out the shape and glued the Divinycell together to a long pice.
I used a rigging screw as a clamp to edgeglue the Divinycell pices.
The edgescarvs were held down with a lot of leadweights to get the panels straight.
Then I put them on. First with the help of a lot of clamps I got them into their places, then I screved them into the woodpices.
The back sidepanels was childs play.
But when doing the foreward bottom panels I had to watch my steps using patience and not rusching things. I let gravity work for me during lunchbreaks and overnight gradually increasing the weight. A small boat has smaller bending radius then a big one and I use very thick Divinycell 4cm wich is nearly 2 inches and its heavy duty quality 100 kilo kubik per meter. But its makes for a very strong boat, well insulated and unsinkable. qualitys I like.
The Divinycell is clued with NM-Epoxy edgewise to at the sherline its glued to the woodenpieces at the frames, then all screves and clamps can be removed.
Here there is still a few screvs left at the shear,
Now she is ready for the final shaping.
I now live in Västervik on the Swedish east coast. Here I have rented a room to build my new boat in. This is how it looked when i mowed in.
After i got order in the mess I put up the fundament.
Then I raised the molds.
As I was standing there brooding, seeing the huge boat in three dimension for the first time i realised that I better start with something smaller, so I took down the frames a recut them to a handier size.
This size suited me better. I named her YRVIND ½ after myself as I hope she will become my better half.
… to be continued…