Doug Dotson dougdotson@nospamcablespeednospamcom wrote:
"Dag Stenberg" wrote in message
...
... pure aluminium has nearly double heat expansion
compared to stainless steel.
Where does that put us? I suppose one can then argue, that when it gets
colder, the aluminium mast shortens more than the stainless steel
shrouds, so those should actually loosen. Apparently I have been misled
earlier by incomplete information....

This jives with what I have observed. Not so much that shrouds appeared
to be loose, but I have noticed occationally that forestays and backstays
appear a bit slack.

Yep, now I heard something from our club: somebody left the mast up, and
it started to wobble in the wind, putting more stress on the hull.

About the risk of toppling over - there seems to have been an occasion
in Cornwall about five years ago, when 50 boats toppled over, because
the gusts had rocked the supports, making them loose. They used logs for
supports, no cradle.

With the mast up, the rocking against the supports of the cradle will be
stronger than without the mast. I hear that one yacht in a marina close
by our place got one of the supports through the hull because of this.

So I remain happy with unstepping the mast for the winter.

Dag Stenberg