Freedom 40 Centerboard

[bad]

Couple of weeks ago we managed to drop our centerboard from the fully raised to the fully lowered position and it broke in the area where the pivot pin goes through the board. We managed not to loose it and pulled it out of the water using the yacht club hoist. This is a 1987, hull 21 vintage boat, center cockpit. We have managed to weigh it and it is 1100 lbs. The head - that portion that stays in the centerboard trunk - is solid glass. The lower, fin shaped portion appears to be a fiberglass shell filled with metal - steel or lead. I thought this may be a good time to take accurate measurements in case somebody has to replace theirs and I will gladly post. There was a boat in Australia that had also lost their board and it was never clear what actually broke. But I imagine it is harder to reconstruct a board not knowing what the original looked like.

Some pictures at this link https://drive.google.com/open?id=0B3nYlNawVM9gfmZmLXI4QUZubzJhdm5aWGFqeFdxSURqNy1rWmVremZvVlJCbVV4Mmt2UTA

Erik

[Castaway]

Wow! I’m not sure I wanted to see that! For years, my CB has been clunking in a seaway. I replaced the bearing, and that didn’t stop it. Now I shall be waiting for it to fall out, like yours. Very skilful to have saved yours from loss.

The F33/UK35 CB is said to weigh 500kg (about 1100 lb); I haven’t checked, but this seems realistic. Why do they need to be so heavy? The boats are not unstable with the boards raised, so the extra moment of the ballast is not essential. If I had to remove mine completely, I would be tempted to remove half the metal and stow it inboard. This would reduce stress on the pivot, facilitate raising, and make occasional ‘depth sounding’ less damaging to the GRP leading edge when sailing in rock strewn channels. I can’t think it would greatly affect the sailing performance, but the logistics of removal defeat me.

I am, presently, replacing the pressure pads on the CB, which are meant to stop lateral movement of the board when lowered, and will post some pictures when complete; these don’t seem to exist on the F40 board, from your photos. Thanks for posting them; it’s always interesting to see how problems can be managed. Good luck with the repairs.

Gerald

[midnightsailor]

Instead of just redoing the solid glass area around the pivet point I think a stainless steel or bronze fabrication of a “cap” over the area of the pivet point , through bolted through the solid glass would be much stronger… Wish I new how to post a drawing of what I have in mind but hopefully it is obvkious. Rick

[bad]

Thanks you both for the comments.

Sailing without a centerboard-there is at least one F40 that only has the keelson, but from photos it looks like it is deeper than ours has been done. Plus the boat in Australia seemed to sail around just fine. I’ve noticed huge differences though in the way the boat handles when turning when the board is up vs down, bother under enine and sail. Stability wise, the F40 supposedly has 6000lbs of ballast. If 1100lbs are in the centerboard, one would want to replace the lost righting moment. That would mean more lead/weight because it would be installed higher in the hull. Guestimating - if the leverage arm of the board is around 6 ft from the center of gravity, and the new lead averages out at 3ft (I think I’m optimistic there) one could figure on twice the weight to replace the righting arm. And that does affect performance and where the boat sits on its lines. We like the board - it’s not quite as traumatic when running agound, and raising and lowering it isn’t the worst. Does become a hassle when it breaks though

Metal head - I’d opt for bronze if possible since it stays submerged. Fabricating in bronze - it can be cast by mere mortals and it cetainly machines and drills better, is worth considering. But that the board has lasted 38 years and I doubt it’s the first time it has dropped (or dropped on other F40) is also a good data point. It was fabbed with polyester and simple roving. Epoxy and uni-glass will go a long way in making it stronger.

We still need to get the pivot pin out and see what diameter it is. That may change the engineering of the repair.

I’ll report…

Erik

[Castaway]

I am (hopefully) attaching a couple of pictures of the centreboard pivot on Castaway; one shows the fore end of the board, the other shows the original pin – since replaced – which is held in a sliding yoke at the fore end of the CB case. I think that the F40 may have the pin located through the keelson; there may be pictures from the refit of Alabama Queen (search Michel’s posts), although that was an F44.

We certainly find Castaway difficult to manoeuvre with the board raised, and usually keep it down except on a long run or in very shallow water. However, I am uncertain of the need for a large righting moment. We never get more than about 15º of heeling in anything less than a Force 6, and we try to avoid going upwind in anything as much or more than that! I am getting older and less fit, so I find winching the board up is quite an effort. I would alter its position more often if that were not the case.

I like the idea of a cast bronze repair, but I wonder how you would bond it to the rest of the board? Perhaps a stainless strap around a nylon bush would be easier?

Regards,

Gerald

[VeloFellow]

My brother is rebuilding Freedom 40 #7. The centerboard is partially down. It is most likely the heavy steel version. We have question about the mechanism as it exists.

There is winch which exerts a pull on another cable, doubled as a safety? The distant end of has an eye splice and u bold jammed at the double sheeve cabin sole of the boat. He was curious if this was the original position of the powered cable end as it gives up one pulley advantage of not hving this free end fixed above.

We know their are a variety of solutions in the various F40 cat ketches. Anyone with one of the other early boats with a similar design?



Mike

[bad]

Mike/All - sorry, but it’s been a while since I’ve checked this thread. We are still hauled out but the center board is coming together and hoping we are back in the water by years end. This long haul-out has been a great chance to get many other projects done while the yard slowly fixes the board. We’ve replaced the entire drive train on our engine aft of the coupling (we have a Sabb 2H (18hp) with a pitching prop that was all original and luckily the boat came with a complete spare shaft, propellor and hub). In order to remove it, the rudder had to come off. That lead to a reglassing of the rudder leading edge which was separating, replacing of the upper and lower gudgeon bushings, rebuilding of the steering quadrant, the idler pulleys and pins, replacing the steering wire with spectra, replacing the edson steering chain and sprocket. In parallel we installed new instruments and transducers (depth and speed), some bronze bow hawsers (had to cut and gas two 6x8 holes in the bulwark immediately after the main mast deck. Then I took off all the cleats and chocks from the bow deck and in a moment of foolishness decided to dress up the deck with some teak (glue down). Now I am struggling how to best lay out the anchor roller etc. I’ll post pictures or a link when I have more time.

Back to the centerboard - As I stated earlier, it is 1100lbs, glass skin of made up of 3 layers of roving. The board is filled with lead or steel, the center of gravity is about 1/3 from the bottom. The head is filled with chopped glass/polyester. The head is now solid using vinylester and a layup consisting of uniglass, carbon fiber, and biaxial. probably 10x stronger than before and hopefully will not be a problem again. The pivot pin was a 3.5" stainless pipe, machined down slightly with a transverse 1/4" pin locking it in place in the trunk (looked similar to Castaways pivot pin). Although the hole could be accessed from the port side, slightly above the keelsom, removal was not contemplated by the builder. We used a hole saw to cut a full sized hole from the starboard side on the keelsom into the bilge and then through the centerboard trunk. Then used a die grinder to grind off the ends of the 1/4 pin, and finally with a large, long drift, pounded out the pivot pin towards port. The new setup is to have a complete fiberglass tube spanning both sides of the trunk. Also we will make the pin full length and have the ability - if ever needed - to pull it out without. I will be taking a template of the board before it is installed.

Mike - Our pulley setup for the board is somewhat different than yours. - our boat is the center cockpit version and there is a bulkhead separating the engine room from the main cabin that is at the aft edge of the cockpit bridge deck where the mizzen mast is located. Inside the cabin from the bulkhead going forward, first there is the mizzen mast, then a cable trunk that houses the lifting cables and guides them to a winch that is mounted to the aft facing vertical side of the cabin roof, immediately in front of the mast. This is an old bronze Merriman cable winch made just for centerboards. Because one can not swing a winch handle past the mast, we use a small steering wheel. Works pretty well. The purchase is a cascading 4x1 with the wires attached to the mast collar of the mizzen on the bridge deck.

From your pictures it is not clear to me if you lifting cables are forward or aft of the mizzen mast but I’m guessing aft since it looks like a nicely painted bilge . You have a 2x1 purchase. If the loose eye was attached to the shackle holding the double cable, you would have three wires pulling on the shackle, giving you a 3x1. Your range of travel doesn’t change but you would need to make sure the wire is long enough and whatever winch it is leading to, can deal with the longer length. Our winch is manual and the gf really can use the 4x1 purchase. The winch is sized for 3/16" wire which seems adequate. 1/4 seems better if the sheaves can deal with it. I have switched to a Suncor sheave on the board with 1/2 pins (There is no reason for you to have a sheave on the board given your setup. You may consider using two saddle clamps on each end of the double wire. I’d feel better about it then .

Finally I noticed that your cable trunk is open at the top. Our wire trunk is continuous from the centerboard trunk to the bridge deck. We have a centerline galley sink that drains into the trunk, about 18" below the bridge deck, but still above the waterline. We sailed in 20kn+ winds downwind once and it was evident that water from the cable trunk got into the galley sink. I can’t recall if the board was up or down.

Erik