Hi Annie,

have you looked at the leeboards on my Rodark design on my page in Box. This type of board could be a good alternative for Puffin. They would clear the interior of the boat from the complexity and intrusion of the bilge boards, and the main stresses from the leeboard hinges would be transferred to the bulkhead forward of the head. The hinge is made from a very robust "T" made from stainless rod, a salvaged 1 1/2 inch prop shaft would be good as a source of material. This would be held to the board by a pair of stainless straps bolted to the solid hardwood boards. The inboard end would pass through a strong angle bracket bolted to the hull and bulkhead. The hole through the hull would be a section of 2 inch stainless pipe welded to the inner bracket with a nylon bearing inside. The friction at the hull would be mitigated by a 1/2 inch nylon bearing plate screwed to the hull with a corresponding stainless steel plate on the leeboard. High density rubber sealing washers would be installed inside and out to prevent water ingress.

  The solid hardwood boards should deploy without additional ballast, however if needed a steel shoe could be bolted to the leading edge at the base. This would then allow you to use the board as a depth sounder in shallow water, without damaging the board. A lifting tackle at the back would be easily accessible from the cockpit for raising and lowering the boards.

   Anyway have a look at Rodark and let me know if you think they would be a better alternative for Puffin.

David.

I don't think the boards need to be ballasted, or heavy enough to sink.  That would be true with a centreboard that needs to sink under its own weight, but you can use one tackle to push the board down and another to pull it up.  When you release the "down" tackle, if the board is not under load, then it will come up easily.  I've seen them pop up on their own!  But usually they need a little tug.  With the lever arm provided by a 5:1 tackle, and the directional effect of the case - the pressure from the tackle can only go in one direction, either up or down - the boards should go up and down easily.

Especially if you put the windward board down just before you tack, when it will have minimal load on it, then haul up the board that was previously to leeward after the tack is complete.  If you were willing to cant the boards inboard at the top by 15 - 20 degrees - whatever the optimal heel of the vessel to windward in 15-20 knots of wind - then the leeward board would be vertical, and you could leave both boards down when short-tacking as the windward board would be canted out at 30-40 degrees and would be providing some righting moment, if it was doing anything.  The top of the cases would take up a bit more space, of course, but you could always stow your wine bottles behind them!

If the boards are built from appropriate structural closed cell foam, with splines, rather like a surfboard, maybe even 6mm thick carbon fibre splines, with some exotics in the epoxy layup, it will be massively strong.

I'm not saying this is the only way to do it, just the way I would.  I might even be wrong, since my daggerboard experience has all been on multihulls. Even though these boards are going on a monohull, though, it is a small boat and the boards are proportionately small as well.

Annie, you said you wanted some lively debate about the Sib Lim challenge, and you are getting it!

PS: (just added this)  Ballasted leeboards may well be the easiest solution here, which can be raised and lowered effortlessly from the cockpit with a single tackle on each board.  I sailed with this set up on Grace Ellen in 2014 and was impressed.  If the hinge pins and their brackets are strong enough, they are structurally very robust.  My experience of daggerboards is that you may well have to step up onto the deck at times to "encourage" them to go up or down, due to pressure on the boards in the case. Since the boat is moving, there will always be some pressure, and no amount of ballast will overcome this.

Dear Arne

Your insistence on my lack of sanity here is wearing me down.  I don't believe that I'm asking for the impossible.  Surely, the point is that when the boards are down, the boat isn't shoal draught?  And my design criteria are not producing a lightweight boat.  There is a trailer sailer, called the Noelex 25 that is very popular in New Zealand and they are not only sailed in open water, but regularly raced: and we get a fair bit of wind in this country.  If a trailer sailer, equally limited by design constraints, can be persuaded to go to windward, why can't my Sib-Lim concept?

Annie,
I hate to be the naysayer (or the devil’s solicitor ) here.

I am sure (as said before) that the Sib-Lim contenders will stand up to quite some offshore conditions, better than that Noelex 25. With really big bilge- or leeboards (Noelex draws 1.4m with c.b. down) there may also be enough leeway resistance.
It is just that the 3 ton Sib-Lims have 2.5times the displacement of the Noelex 25 on about the same waterline length. My fear is that this last factor, heavy displacement for the wl. length, will make the Sib-Lims slow, since there is little room for increasing the sail area.

But enough grumbling from me on this thread,

Good luck!

Arne

David Webb wrote:

Arnie, David,

 at four inches thick and without holes in the bottom, the bilge boards, when fully immersed will displace about 200 pounds of water, my original two inch thick solid hardwood boards weighed in at about 130 pounds, still very heavy for Annie to lift. They will need to weigh well over 200 pounds if they are to deploy under their own weight. They will also need this much lift to fully raise them and I think that this will be too heavy for Annie to manage, correct me if I am wrong Annie. This is with no allowance for friction of the board in the case. If there are holes in the bottom then the structure of the board will weigh about 60 to 70 pounds and this is all that Annie will have to lift plus friction, but this is still marginal for her strength I would imagine. With a two to one tackle and a small winch I would see it as  quite possible. This would need a sheave embedded in the top of the board and a sheave with becket at deck level,  with the tail led back to the cockpit and a small winch on each side. If the boards are open at top and bottom then ant stones or mud could easily be dislodged with a stick poked down from deck level.  What are your thoughts Arnie, David, Annie.

You are quite right: 200 lbs is way too heavy and a fair bit of the overall displacement.  However, if they are made of wood, surely a good portion of this weight will be supported by water?  There do seem, she said somewhat plaintively, do be other boats of this size sailing around with boards of manageable weight.  I assumed that there would be some sort of purchase to raise and lower the board; however, I don't think a winch would be acceptable: too slow and, equally to the point, too expensive.  I want to be able to rattle the boards up and down fairly smartly.

I think I might just saw off Fantail's keel and add twin keels.