Winter time

It is cold in Houston, not the right time for epoxy... So progresses are slow.

I have redesigned the centerboard lifting system a bit. The original design was difficult to operate and I was not confortable with it. I have installed a 600 lbs manual winch borrowed to Kerness trailer with a web strap. There is a key slot in the centerboard top, where the strap is kept in place with a pin. Very efficient and simple design and no more issue with lifting the centerboard.

I had to use my sander a bit more, to make the center board move freely in the trunk.

The ruder is ready... almost!

On each side of the trunk, there are 2 hatches and a couple fastners to retain the lead in place. I will place the lead in heavy fabric bags and fasten them to the bottom with straps.

In the front, the space below deck is water tight.

The canopy is slowly covered, day after day, with 40 mm x 12 mm strips. Long process, but it is beautifull.

All the best for 2011...!

Center board

Last week-end was a busy one for Lady C....


There was this old boat vendor on the port of Brest, who told me once a motto he said was coming from our old neighbors, accross the channel. He was the kind of old Breton that do not really like the neighbors, but respect them as great sailors. So I was going to start the installation of the legs on my boat back home and I needed to drill 4 holes, about 1/2" in the hull. Humm, the kind of thing, I do not like much. So the old man told me: "as the englishman says, it is better to measure twice and drill once, than the opposite". So, I wanted to try the big centerboard in place before we glued in place the final soles pieces around the trunk. If I had to modify the trunk, better to know it now rather than later.
So the first thing was to lift the boat of its cart. This was done with the tack of Lady C. on one side and the tack of KerNess on the other side and a securing web. All was attached to the garage roof framing.
Then the centerboard was attached to the cart, ready to get in the trunk. The cart was pushed underneath the boat, centerboard inside the trunk.

Last piece was to lower the boat and have the kids put the axis in place through the trunk and centerboard.

It all went very well and we were able to test the lifting mechanism. Hughh it's heavy. I may have to rethink it a bit. At this moment, we have 4 strings, I may be able to add one more.

I also took the opportunity to trim the trunk to the outside shell shape and tapped to layer of cloth from inside the trunk to outside hull.

Next week, we need to glue the sole in place and get ready for the decks...

Centerboard or keel or both

Not much to say since last post, other than a lot of dirty sanding time on the hull, before flipping it. But now, I should be OK in the future. I added fiberglass on the hull sides up to the deck, in and out. I also laid two layers of fiberglass on the hull external bottom, for tear and wear.

Then, flip it...

Now time is for centerboard and keel. This is the design change I am trying, since I would like that this boat be either able to have the shallow draft or the preformance with the keel.

A piece of rope, four pulleys and some magic later.... Center board is gone!

Oooohh, how does that work? OK, here is a picture of the trick. You notice that the centre board is not the final one... The final one is ready, but way to heavy for that dummy run.

To install the keel, which a bit thinner than the centerboard (50 mm vs 60 mm), we install a box that fits inside the centerboard well. Note that the bolts for the centerboard go on each side of the keel.

Finally, in position in the large saw cut in the boat's bottom...

Lady C. is making progress!

Re-engineering

This lifting keel capability has been taking my mind for too long and I was not able to find a lifting solution that I liked very much. In fact I would like a centerbord version for easy launching and shallow water sailing, with the at sea performance of the keel version... The big issue with the keel version, is that I am afraid it becomes so complicated to launch and get started, that it will kill the rest of the sailing fun.

Then I came accross a post on the bateau forum http://forums.bateau2.com/viewtopic.php?f=3&t=17984&hilit=centerboard+sb18, where a member was thinking about keeping the option of both centerboard or keel version on the same boat. This allows to use the centerboard or the keel. It does not lock from start, which design the boat version will be. It requires a simple modification of the centerboard trunk and the addition of a couple removable inserts in the centerboard trunk, when the lifting keel is used. The width of the keel and the centerboard is about the same and I will use the holes made for the axis of the centerboard manoeuvering sheaves to lock the inserts in position. The inserts will become the foward and aft guides of the lifting keel trunk. Here is a quick sketch of the option I am about to take.

Sport Boat 18

So, now I have the drawings of the Sport Boat 18. A few data:
Length: 5.5 m
Wength at Water Line: 5.2 m
Draft (centerboard): 0.18 / 1.4 m
Draft (lifting keel): 0.46 / 1.57 m
Displacement: 663 kg
Ballast (centerboard / keel): 182 / 166 kg
Sail area: 22.4 m2
I really like the design of this litle boat. It looks very nice and must be very fast.
I went through several blogs of boat buiders and I have two fundamental questions that which I have difficulties to decide:
1- Lifting keel or Centerboard
2- Mast step on keel or mast step on deck
I would like to be able to take the boat in shallow water. Though it is not an absolute madatory thing, sailing in protected waters in the Houston area or at our place in Britany requires some ability to sail in shallow waters. The lifting keel system on this sport boat requires the main sail hallyard and the boom. So impossible to lift the kill at sea... It is a disadvantage in my eyes. However, this is a sport boat, if I start to question the fundamentals of a boat that is supposed to go fast, I should rather built a less extrem design, with a centerboard... I have looked a lot at the drawings, and I think I may be able to have some system install to lift the keel "partially" to meet my criteria. This may be adapted at a later stage. The other issue is trailer and launching from the trailer. Here again, I will need to look at how this can be done easily.
The other question regards the mast and it mainly concern the ability to rig up or rig down. I was more in favor of keeping the original design, but rigging up a mast 9 m long will be a difficult operation. I am looking at a carbon fiber mast to see if I can have it lighter than the alluminum mast. I have seen some of the SB18 under construction for a roof stepped mast. I do not really see how the mast can be rigged up with a hinge system on top of the roof. There are at least one interference with the cuddy top and one with the keel in its upper position.

After putting a lot of thoughts in all this, I am glad I come back to the original design of the boat and wont have to denature it.