small boat rigging advice

[steve yates]

2 issues I'm looking for help with, possibly related. I've put the mast back up on my bradwell 18, and the cap shrouds can't be tightened enough. The rigging has swaged terminal for a bottle screw, and the bottle screws did have bent forks at the other end, so I chucked them. Now I cant remember if they were shorter than the new ones I replaced them with. It is a masthead rig with cap shrouds and lowers, the lowers I can get some tension but the bottle screws are closed up, so no more room to improve.

I'm a bit stumped as to why as the same rigging seems to have changed lengths! Which leads me to the forestay, possibly if I sort this the rest may fall into place, or not?

Its a furler, (plastic, problem plastimo or something)and it's always had a bit of sag in it, not to mention being attached with a toggle and a shackle. The backstay splits low down and both ends went to shackles at the stern.

I have got rid of the shackles for toggles, and managed to get the forestay attaching to a single toggle on the stemhead. There is a bottle screw between two prongs, and then some kind of aluminium plates screwed through the centre of the bottleswcrew and the toggle forks, which I don't really understand. Is it to prevent the spinning of the furler unwinding the bottlescrew?

My problem is, I tensioned the bottle screw up to get rid of the sag, and the two plates dont marry up now. I got some good tension further out on the stemhead but the plates phyysically didnt fit to put back in place, so I had to move it back again, and then just join the end of the plates to themselves, as I couldn't align through the toggle forks. The two pics might make it clearer. The first is as it was, the second how it is now.

So my questions are, should the forestay be taught? Are those aluminium plates really required or is the bottle screw sufficient in itself? Can I use the backstay to put the tension into the forestay and remove the sag? as I have a fair bit of bottle screw left to play with there, or will that just bend the mast back?

Thanks

 

[William_H]

The plates as far as I can see are there as you guessed to lock the turnscrew in place ie stop rotation once the tension is set. You could also use locking wire or similar through the hole and around something rigid like a fork end. If you take up the forestay rigging screw tighter then this should give you more ability to tighten the cap shrouds and inners. I am guessing here that you have a fractional rig with spreaders swinging aft to meet the cap shrouds. Generally on any rig the forestay is not adjusted but rather the tension is applied to the forestay by the cap shrouds and back stay. The forestay adjustment really only sets the verticality of the mast ie the amount it leans back. This affects the position of the centre of effort of the sails (as related to the centre of lateral resistance of the keel/hull. But actually makes very little difference so if it looks right (near vertical or slight lean back) then it will be ok.
The other option is to raise the mast by putting packing under the base. This can in effect shorten the shrouds. With the fractional rig with cap shrouds set aft of abeam the mast the rig is essentially held up by the cap shrouds and forestay. So set up tensions etc with back stay loose. Then back stay is tightened to help tension the forestay and to bend the mast a little (top back middle forward) when wind is stronger. This bending back of the top of the mast takes tension out of the leach and allows the top of the main sail to fall away. (good in a gust) Some racing boats around here have the back stay adjustment at hand for the main sail trimmer right next to vang and main sheet. You will probably however just leave the back stay tension as set. ol'will

 

[DownWest]

Backstay tension on a split setup can be done with two blocks connected with a strop and downhauls. Pulling down pinches the V and tensions the stay.
Otherwise what Will H said.

If I understand your photos and text, maybe you need to redrill the two straps to match the closed up turnbuckle? Fore stay should not sag, as it affects the cut of your jib (so to speak )

 

[Easticks28]

I would suggest that first you get a couple of replacement bottle screws that are a bit shorter than the first replacement bottle screws....
It would appear that they are longer than the knackered ones you threw away....

 

[steve yates]

I'll get shorter barrelled screws, and I I'll cut the plates and redrill them too, thank you. I have torn out all the internal joinery, including the mast compression post. I never intended to tension everything up until I put the post back, but perhaps the weight of the mast alone is enough to give a little sag to the roof, that I can't detect by eye? 'll reinstate that tomorrow and see.

 

[William_H]

I was a bit lazy yesterday in not checking photos of the Bradwell 18. It would appear that you have a mast head rig with spreaders and cap shrouds square to the beam intermediate side stays chain plate aft of abeam the mast and an inner forestay. So perhaps my advice was misleading. The cap shrouds will not change in length with mast rake. (couldn't think of that word yesterday) So if cap shrouds are too long you will need to shorten them or use a shorter turnscrew or jack up the mast either wood under the base or you should check for sagging of the cabin roof and perhaps spacers under/over the support post.
Cap shrouds will not affect the forestay tension. The back stay will do that. However inner forestay and intermediate shrouds should be tensioned to make the mast straight or slightly middle forward. ol'will

 

[steve yates]

Thanks will, the cap shrouds are the exact same ones that fitted before the mast was dropped, part of the reason for my post. No inner forestay, she is only 18ft long
Tho you may have just triggered something, I wonder if i have attached the caps to the lowers chainplate and vice versa? I dont think so but now I'm secondguessing myself. Will have a look and check later. Something has changed, which shouldn't have, thats for sure.
Ta.

 

[Easticks28]

Thanks will, the cap shrouds are the exact same ones that fitted before the mast was dropped, part of the reason for my post. No inner forestay, she is only 18ft long
Tho you may have just triggered something, I wonder if i have attached the caps to the lowers chainplate and vice versa? I dont think so but now I'm secondguessing myself. Will have a look and check later. Something has changed, which shouldn't have, thats for sure.
Ta.

When re-rigging, I always tell myself "cap shrouds aft "

 

[steve yates]

They are in the right places, but I have discovered the main issue! It was the removal of the compression post, (to refurbish the joinery below and above it) even with everything slack, the weight of the mast alone has lost a good inch in the roof. Am going to try and jack it up with a car jack and some blocks when the tide goes out, too bouncy just now. Failing that it will have to just come down again, sort the post and then raise the mast again. Ah well.

 

[Spirit (of Glenans)]

Yes you need to get the compression post reinstalled before the mast punches through the coachroof.