shroud tension

[viva]

wooden mast - gaff rigged. Can anyone give me a rule of thumb on how much tension to have in the shrouds. The boat has come back from having her mast raised and 1 shroud is "slack" I can't get the boat back to the yard and and there are no riggers round here

 

[bluemoongaffer]

I have a similar set up but probably much smaller boat (19ft). I just tighten the bottle screws until only a small amount of movement when I hold onto them and so that the leeward side doesn't fall loose when tacking. I also try to get them so that the staysail doesn't sag excessively - perhaps just an inch or two of sag in the middle of the forestay. I don't think the shrouds should be (or need to be) very tight - so not to the point where they twang. Not sure if that helps much but it has reminded me to tighten mine up this weekend!

 

[jerrytug]

wooden mast - gaff rigged. Can anyone give me a rule of thumb on how much tension to have in the shrouds. The boat has come back from having her mast raised and 1 shroud is "slack" I can't get the boat back to the yard and and there are no riggers round here

Hi Viva. Can you give some more info...what boat is it, what is the mast made of, how is it stepped, how is the rigging tensioned, and where are you sailing out of?

1st, do not, repeat not, keep hardening up the lee rigging, then going about and hardening the 'other' lee rigging. You will knacker something, probably serious.
2nd, buy " Hand, Reef and Steer" by T.Cunliffe. The only book about operating gaff riggers, and the best book by TC, by miles.
cheers Jerry
edit, there is an article, with numbers, on the classicmarine website I believe.

 

[viva]

Hi Viva. Can you give some more info...what boat is it, what is the mast made of, how is it stepped, how is the rigging tensioned, and where are you sailing out of?

1st, do not, repeat not, keep hardening up the lee rigging, then going about and hardening the 'other' lee rigging. You will knacker something, probably serious.
2nd, buy " Hand, Reef and Steer" by T.Cunliffe. The only book about operating gaff riggers, and the best book by TC, by miles
cheers Jerry
edit, there is an article, with numbers, on the classicmarine website I believe.

Thanks for your help - she is a Norfolk Smuggler so gaff rigged cutter.- mast is spruce I think and is tabernacle stepped. Shrouds are adjusted by conventional bottlescrews . I am in S.Brittany
Thanks for the book advice I have ordered it.

 

[Woodlouse]

Just nip them up on the bottle screws till they feel good to you. If you say one feels slack then tighten it up till it feels the same as the other one. On a Norfolk smuggler the loads are all pretty small so it's difficult to get it wrong.

 

[Lakesailor]

I have had small boats. As long as the mast is vertical athwartships the tension on shrouds for the low loads like this is not critical.
I usually get them so thrumbing them gives a double-bass sort of note. You can get the tension pretty even using this musical method.

My Solo dinghy had shrounds which were designend to be slack, even at rest.

 

[Wooden Boat Fittings]

I agree with LakeSailor. On a boat like this, the shrouds (and swifters, if that's that's what they are) are really there as backups if anything goes wrong. Get them thrum-tight, and then check by lying on your back on the house that the mast is vertical. Then you're done. (Over-tensioning them only tends to drive the mast's compression-post down through the keel.)

Mike

 

[Kukri]

On a gaff rigged boat, the lee shrouds should be slack when the boat is on the wind.There is no point whatever in tightening them more than that.

 

[Sniper]

Tell me if I'm wrong but the debate around shroud tensions seems as much to do with the material from which the rigging is made as it is to do with the type of rig. Most of the arguments I have seen for very high rig tensions seem to be driven by the need to reduce the flex and work hardening (probably not the right term) in stainless steel wire. Secondary to this seems to be the need in some rigs to produce prebend in the mast.

If this is the case, then presumably any discussion around reduced stay tensions in gaff rigged boats should be predicated on the assumption that the stays are made from galvanised steel, as stainless wire on a gaff rig will be subject to the same fatigue as a more 'modern' rig if not subjected to sufficient pretensioning.

For what it's worth, I never feel happy subjecting my wooden Bermudian rigged boat to the pretensioning suggested by rigging experts for FRP boats; if it means I have to replace my rigging more often, so be it - it's still cheaper than making good the damage that could be caused by over tensioned rigging, as I found out a couple of years ago when my mast supporting partners delaminated.

 

[Swg]

Shrimper shroud tension

On the cheaper vsn of the Gypsy I tighten until I can ping and hear a low note but not so tight that I could play a tune. On my boat that's hand tight plus a couple of whole turns using a screwdriver through the bottle screw.