"Wayne.B" wrote in message
...
On Tue, 14 Mar 2006 00:31:35 -0600, sherwindu
wrote:

All these horror stories makes me wonder. I have used snap shackles for
35 years
and never had the slightest problem.

You've been fortunate. There are actually conditions where some snap
shackles are able to flog themselves open just from inertial forces.
I had one set that needed to have extra strong springs installed on
the shackle pin because it was happening too routinely.

Having the release pin or its lanyard snag on something is another
proven shackle opener.

We had a situation on one of our boats where that happened at the tack on a
jib. It was a few years ago... the halyard wasn't all the way up and was
bouncing up and down enough to pop the shackle. I believe the shackle was
defective, so I'm not sure if that was the reason or if it would have
happened anyway.

--
"j" ganz @@
www.sailnow.com

On Tue, 14 Mar 2006 12:02:58 -0800, "Capt. JG"
wrote:

I believe the shackle was
defective, so I'm not sure if that was the reason or if it would have
happened anyway.

Probably not defective strictly speaking, just a spring too weak for
the flogging forces generated. My issue was on spinnaker halyards if
memory is correct. When the wind was blowing hard the spinnaker would
get about halfway up, and poof, the shackle would magically open. I
originally assumed that the shackle had not been properly closed or it
was some kind of weird one-time event but after several more fiascos
it became clear that the shackle was actually opening under its own
volition. The cure was a stronger spring which fortunately my rigger
had in stock.