"Walt" wrote in message
...

Rig tension looks about right to me - very loose when the boat is not
actually under way. Why leave the rig under tension any longer than
you
need to?

Because flex=fatigue. A rig left loose wears out faster as it flops
around.

Um. No.

Sorry.

Um. Yes.

Indeed yes if the boat is afloat

Perhaps you should ask Brion Toss.


Be my guest. Phrase the question like this:

"I've got a 505 that I dry sail from a launch dolly. Should I loosen
the rig when I bring her ashore?"

Here's the answer:

Absolutely. With a dry sailed dinghy, you always slacken the rig once
ashore. It takes the tension off the hull, which will fatigue if kept
under load.

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.

"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

Edgar wrote:


Because flex=fatigue. A rig left loose wears out faster as it flops

Indeed yes if the boat is afloat

Agreed.

But the boat in the picture is not afloat. It's on a launch dolly.

//Walt