Centreboard Issues on BRE

[Llafurio]

My centreboard would not go down all the way any more, so I decided to fit a downhaul.

First had to hammer a wedge between mahog top and case to prise the case open. Silly sealant glue there. Unserviceable at sea like this.

1.
What hindered my board from going down was not the friction of the pulley system inside the case, it was -only- the too small diameter of the through-deck eye fitting at the rear end of the centreboard case. The 6mm uphaul rope fitted by the yard, when slightly frayed, does not glide smoothly enough through the 6mm through-deck fitting. Have to install a bigger through-deck fitting.

2.
My boat always had a sh... balance on the rudder. She had a leeward tendency, and was poor to go through the tacks. Now I know why: The board COULD NOT go down all the way but stayed approx 20 degrees from vertical,  independent  of the downhaul friction problem, because there was a knot iin the wrong place in the uphaul pulley sytem. Glad I finally found that. IMO a yard mistake.

3.
The 8mm rope connecting the centreboard head to the pulley system is -again- smeared to the head with resin, and such is unserviceable at sea. Why?

4.
Finally fitted a downhaul rope, simple enough. I can now fully control the position of the centreboard.

Glad I looked in there.
 
C.

[charliea]

Certainly agree that sealing down the lid on the centreboard case is daft. I've had to remove it a couple of times to unjam the uphaul so have now removed all the sealant.

I check mine fairly regularly but without the sealant I'm relying on the screws to hold the lid in place.
They don't actually have much to bite on as they pass straight through the casing. At some point I may try to back the lip of the centreboard case with two lengths of hardwood so the screws are more effective.

A jamming centreboard is always a worry. If I was specifying the changes I'd be happy to pay for in a custom BRE a hinged lid that gave easier access to the centreboard would be top of my list.

[Llafurio]

Certainly agree that sealing down the lid on the centreboard case is daft. ...
... A jamming centreboard is always a worry.

How can the centreboard uphaul jam?

[charliea]

I'm not sure how it happened or if I remember the details correctly, as it was a couple of years ago.

As far as I recall the centreboard went down ok but didn't budge when we tried to pull it up again. We were on a mooring off Dale so had plenty of time to sort it out, but a lack of tools meant I couldn't get the centreboard lid off.

After hauling on the uphaul for a while I stripped off and had a look underneath. We'd spent the night before on a mudflat so I thought I might find something was caught on the centreboard or jammed up the casing. In fact a loop of the uphaul had somehow found its way round the wrong side of the centreboard. The loop was visible sticking out of the hull and was also jammed itself between the hull and the centreboard.

Ann got in as well and we had a fun time hauling on it until it came loose. I seem to remember we managed to pull up the CB about half way using a line slung under the boat. We could then get the loop back round to the right side.

When we got home I was able to get the lid off and found that one of the sheaves on the block (or tackle, I'm never sure which is which) had collapsed so the uphaul was running round the steel pin. I replaced them with HS Sprenger blocks and so far have had no more problems, although I try to check them regularly.

I'm also really careful about lowering the cb onto the trailer when travelling. I suspect it may have been forgetting to do this that caused the original problem with the sheave.

[charliea]

I seem to be unlucky with sheaves.

When choosing the replacements for the centreboard I found a technical section in the Sprenger catalogue that differentiated between three types of block.

Sliding Bearing
• heavy-duty sliding bearing (yellow)
• breaking load: min. 600 kg
• safety working load: min. 300 kg
• especially suitable for standing loads

Ball Bearing
• easily running plastic ball bearing (red)
• breaking load: min. 600 kg
• safety working load:  min. 150 kg
• especially suitable for slightly veering

Needle Bearing
• low-friction needle bearing - stainless steel (blue)
• breaking load: min. 600 kg
• safety working load: min. 300 kg
• easily running even with high loads

I went for the 'sliding bearing' type, no idea if it will make a difference?

[Llafurio]

... We'd spent the night before on a mudflat ...

... which would explain how a sling of the uphaul tackle could get round the board.: When one forgets to uphaul the board (and thus keep the tackle under tension) before falling dry the uphaul gets so slack, its pulley rope can go places where it should not go.

And yes, any single trailering without releasing the board uphaul for the board to rest on the trailler keel rollers is a real killer for the uphaul system The dynamic forces from the board swinging up and down during the drive over bumps and dips add to -and far exceed-  the static forces of simply holding the board up. The problem was always there with the lighter weighted BR centreboards, and increased with the ballasted BRE boards.

BTW, good idea to glue two strips of hardwood under the centreboard case GRP flanks to give the screws better grip.

[Llafurio]

I seem to be unlucky with sheaves.

When choosing the replacements for the centreboard I found a technical section in the Sprenger catalogue that differentiated between three types of block.

Sliding Bearing
• heavy-duty sliding bearing (yellow)
• breaking load: min. 600 kg
• safety working load: min. 300 kg
• especially suitable for standing loads

Ball Bearing
• easily running plastic ball bearing (red)
• breaking load: min. 600 kg
• safety working load:  min. 150 kg
• especially suitable for slightly veering

Needle Bearing
• low-friction needle bearing - stainless steel (blue)
• breaking load: min. 600 kg
• safety working load: min. 300 kg
• easily running even with high loads

I went for the 'sliding bearing' type, no idea if it will make a difference?

You did right, in terms of value for money, and robustness.
The unsuitable blocks for the centreboard uphaul tackle are the -red- plastic ball bearing ones. As I said above, the dynamic forces from the uphauled ballasted board swinging up and down in a swell or during a trailer drive are critical, and require blocks with the best possible working load. I once destroyed in a regatta a ball bearing block in my BR jib halyard system. Indicating not just the load in the jib luff wire, but also the vertical downward pressure in the main mast. That is why -btw- I did not go for the new taller bermudian mast on the BRE.
C.

[Graham W]

On the BR20, the centreboard case wooden capping is screwed down rather than sealed, which is the good news.  The bad news is that the screws are drilled through the centreboard case GRP, which means that they are not secure.  Mine came completely adrift once when sailing off Corfu after over-enthusiastic crew tried to fully lower the centreboard while we were already sailing to windward.  Luckily the local taverna owner had some spare trellis battens which I fixed underneath so that the screws had something to bite into.  Now replaced with something more permanent - thoroughly recommended for all BR owners.

Similarly, the centreboard uphaul fittings on the BR20 are screwed into bare GRP on the side of the centreboard case and can also come loose.  I’ve replaced my screws with nuts, bolts and penny washers.

I’m a fan of HS Sprenger blocks too.  There used to be a UK seller who had bought a whole load of (bankruptcy?) stock and was selling it off cheaply but he’s no longer about, unfortunately. I think the full range is available from svb24.de and probably also from toplicht.de but thanks to the weakness of the GB£, they are somewhat more expensive these days.....

[Llafurio]

On the open BRs the centreboard uphaul mechanism is very different from the BREs. On the BRs, if you do not release the uphaul for trailering, the foremost screws holding down the wooden case top break loose from the upward pull exerted by the downward swinging board.

A wooden underlay helps the screws to new grip, or you can put "Fischer UX" plugs in the broken out thread holes which form a nylon knot around the screws inside of inaccessible cavities.