Rigging during the winter

[derekgillard]

Our Sadler 29 will come out of the water in Jan for three months, if you were to do this (eg have a boat in commission for 9 months) would you slack off the rigging during the 3 lay months, indecently I always slack off the back stay when leaving the boat .

Thanks for the advice in advance.

Delbouy

 

[Guest]

'indecently I always slack off "

/forums/images/graemlins/shocked.gif Interesting !!

Ok - all boats will tend to pull out of shape to an extent when out of water. (Often bog doors catch .. draw bolts don't fit ... etc). The hull is no longer completely supported throughout its length. It is localised now by struts / props etc. and keels. Allied to rigging this does produce different stresses.

But you also have to weigh up - slacking rigging may have the mast moving in its mount creating other stresses / actions.

My boat - when lifted the few times ... I just took a tutn or two out of bottle-screws - just enough to take out the in-commision tension ...... but not enough to let mast move. The mast is still trying to move with windage etc. - the hull is now immovable object - unlike when afloat !

 

[derekgillard]

We had new rigging two years ago and the rigger told us to back off the back stay every time we leave the boat, of course I would back it off when on a run and tighten on a beat ETC, I am inclined to take a turn off all the rigging when out of the water???

Delbuoy

 

[RobBrown]

For boats ashore with the rig in place, the Selden mast tuning guide advises the following:
Decrease the tension of your lateral rigging slightly just
to ease off the load on the hull. No part of the standing
rigging should be slack. Slack rigging will create substantial
wear during the winter.

Rob

 

[Guest]

[ QUOTE ]
For boats ashore with the rig in place, the Selden mast tuning guide advises the following:
Decrease the tension of your lateral rigging slightly just
to ease off the load on the hull. No part of the standing
rigging should be slack. Slack rigging will create substantial
wear during the winter.

Rob

[/ QUOTE ]

Duh ... think I said that ?? /forums/images/graemlins/wink.gif /forums/images/graemlins/wink.gif

 

[johnalison]

The Sadler hull is fairly stiff (I had one for 15 years) and it probably doesn't matter a lot. It used to be said that you should slacken the rigging as the cold would cause it to contract and tighten, and then someone came up with the answer that the mast would contract even more and thus slacken the rigging. I'm not sure if this is true, but a lot of us keep the boat in commission in winter and tend not to worry about it.

 

[VicS]

[ QUOTE ]
then someone came up with the answer that the mast would contract even more and thus slacken the rigging. I'm not sure if this is true,

[/ QUOTE ] Simple enough to confirm, and by application of a bit of schoolboy physics, quantify.

Kaye and Laby gives the coefficients of expansion for aluminium and stainless steel as 23.1x10^-6 and 9.5x10^-6 respectively. A little bit of simple arithmetic tells you that a 10 metre aluminium mast will contract (or expand) by 0.136 mm per degree more than 10m of rigging wire. Compared with the 3 mm of stretch per 2 metre, or 15mm in 10m, for a rig which is "correctly" tensioned according to Selden that's negligible.

Conclusion, just slack off a bit of the tension as suggested by SBC and supported by Selden Masts.

 

[FAITIRA]

No I wouldn,t slack off, more movement more fatigue, if it was bending this boat I would be very surprised.

 

[PeterGibbs]

I do the same - 5 months out of the water, mast standing. Done so from new. Never touch the rig setting except to ease the tensionable backstay a little. What would be the gain from working the threads of the bottlescrews?

PWG