Loosen rig when hauled in the winter?

[Bob Pingel]

Up here in WI, we haul our boats in the winter and typically store mast up. Every year, someone questions if you should loosen the rig when hauled - typically stating material contraction due to low temp.

Does anyone have a definitive answer, or even educated opnion on this?

It appears that aluminum has a higher coefficient of expansion than stainless steel, so it would seem that the spar would get "shorter" than the wire in low temps.

We also know that hulls change shape when hauled, but I don't think we know enough about the "bulges" that emerge to measure the impact on the rig.

I know you don't want to truly slack the rig, but is it warranted to take a few turns off and why?

Thanks,

Bob

[Ian McColgin]

The prevailing wisedom around here is that assuming you can set the boat up so well that any side loading from wind won't topple her over leaving the rig up is good for the boat as it keeps her from sagging at the ends. Not that that seems much of a hazard assuming proper placement of poppets.

The main reason for keeping the rig up is cost. This may be a pennies wise pounds foolish way to evade a careful and responsible look at the whole stick and its components. Also, I've experience with three boats where the aluminum mast gained such an electrolytic weld with the stainless step that the only way to get it out was to cut. I really think you should pull the stick on each haul.

Most folk don't slack the rig, at least not much. If you've the stays tight enough to prevent too much mast vibration, then it's tight enough that the microscopic shrinkage in the cold won't be making any real difference.

The biggest problem with not slacking the rig a scoootch - no more than a turn or two - is that it's easy to just ignore the turnbuckles alltogether. After a few years of that, the adjustment option is pretty much lost. A few more and the turnbuckle may be compromised.

G'luck

[Brion Toss]

Hi there,
It is true that aluminum has a much higher coefficient of expansion, but that assumes analogous structure, and that ain't the case here. The mast is a column, the wire is a series of spiralling cylinders, and all bets are off. Rigs get tighter in the winter, and this can be easily tested, of course, with tension gauges in various temperatures.
That's just one variable; haul the boat, and now the hull shape will change as well. Best to document that separately.
Finally, in general, rig tune does nothing to cause or prevent hogging; that's a matter of relative lack of buoyancy at the ends. One proof of this, of course, is that power boats hog.
In sum, a little simple measuring will tell you how much, if any, to loosen or tighten the rig relative to temperature or hauling. Around here (Puget Sound), tuning for light-air summer sailing can often automatically adjust, in Winter, for heavier airs.
Fair leads,
Brion Toss