Re: Almost lost my mast.... operator error.

DAVID_KAUTZ@HP-Sunnyvale-om5.om.hp.com
Fri, 14 May 1999 11:21:32 -0700


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West Wight Potter Website at URL
http://www.lesbois.com/wwpotter/
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Bill,

Whether or not you are compromising the strength of your rig would depend on
some of the details of how you are using the bolts. If the bolts are threaded
all the way up and you are using a bolt that fits into the existing holes, this
is to say you replaced a 1/4" clevis pin with a 1/4" fully threaded bolt then
you have a significantly weakened connection. In shear, the bolt will be
slightly weaker than a pin of the minor diameter of the threads (the bottom of
one thread to the bottom of the one opposite). If you are using longer bolts
with an unthreaded upper section and cutting them down so that the entire loaded
portion is unthreaded and a few threads remain for the locknut than you should
have a secure system with equivalent strength.

A problem with threaded fasteners in the marine environment is crevice corrosion
between the components (there is a helical shaped void remaining after a bolt
and nut are assembled). But since you are using the nut essentially only to keep
the bolt from sliding out, a compromising of strength there due to corrosion
should be inconsequential.

Hope this helps,

Dave Kautz
P-15 #1632 Tilly Lucy
Palo Alto, CA
______________________________ Reply Separator _________________________________
Subject: Re: Almost lost my mast.... operator error.
Author: Non-HP-ttursine (ttursine@gnt.net) at hp-boise,mimegw7
Date: 5/13/99 8:21 PM

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West Wight Potter Website at URL
http://www.lesbois.com/wwpotter/
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> My rigger has told me a zillion times that the 95% of rig failures on
> cruisers are caused by a lost retaining ring or or cotter pin. So TAPE THEM
> ALL DOWN with rigging tape, friends, so a loose line can't whip them out or
> rough seas jiggle them out. That includes quick-pins on your forestay -- it
> only takes 30 seconds when rigging.

Being almost entirely self-taught in these areas, I apparently do some
unusual things. In this instance, I use SS bolts and aircraft nuts for
all fastenings that secure standing rigging. Not a clevis pin (nor,
obviously, cotter pin or ring) to be found. This is most assuredly
secure and inarguably faster, but does anyone see anything wrong with
it from any other viewpoint?

Regards,

Bill Combs
WWP 19 #439 (Aug 1987)
"Ursa Minor"
Fort Walton Beach FL
ttursine@gnt.net