"Edgar" wrote
Fatigue is failure of a component (in this case a wire) by reason of
repeated cycles of stress which individually are below the elastic limit of
the material. This happens if you leave the rigging slack while the boat is
rocking about on a mooring. I knew a guy who did this and brand new rigging
broke overnight as his mast twanged repeatedly at its rigging as the boat
rolled (shock loads are about three times as stressful as steady loads).
It is not fatigue if the hull slowly distorts under prolonged heavy loading.
This is 'creep' of the hull material and if you must have a dinghy rigged
that tightly then you should certainly slacken it up when you haul her
ashore.


What about stupid people who make their standing rigging looser for the winter?
They say it's because the cold shrinks the wire and puts more stress on it. Duh?
Maybe that might make sense for wooden masts but not for aluminum masts. Aluminum
shrinks too when it's cold. So the tension stays about the same hot or cold.

Cheers,
Ellen