Re: Cotter Rings
Tue, 18 May 1999 20:13:47 EDT

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West Wight Potter Website at URL
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In a message dated 5/18/99 12:23:58 PM Pacific Daylight Time, writes:

> we have a consensus about the SAFEST STRONGEST way to keep your
> rigging attached??? i've just bought my p15 had it out twice and I don't
> want to chance losing my rig. short of leaving too much sail up in heavy
> weather, what is the best way to attach rigging? Judy, I'd like to hear
> from you, sailing in sf bay and all....
> Ken Silverman, p15 "Vegan Lorax"

Ken et al,

I go by the advice of my rigger, Bruce at Svedsons Boatyard in Alameda. He's
the boss of the rigging shop that re-rigs million dollar yachts and little
boats like our Potters. He's a racer who has won several single-handed
long-range races. He sails hard, rarely breaks anything, but he's seen lots
of rig failures for lack of maintenance and inspection.

Last fall, I paid him to inspect Redwing's rigging and hull from top2bottom,
tune the shrouds, and give me an oral report and recommendations (captured on
audiotape) . Here's some of what he told me, as best I remember it:

*Tape all cotter pins and rings with rigging tape so they can't be snagged
and pulled out. Zing! : ^ (

* Use the correct length clevis pin (those 1/8" to 1/4" pins with a head on
one end and a hole for a ring on the other). Don't use one that is longer
than you need. Zing!

*Use the correct diameter clevis pin for the hole. Snug is good. Too small
is bad. Point loading is bad.

*Use the correct diameter cotter pin or ring for the hole in the clevis pin.
Snug fitting is good. Don't use one that is too small.

*On cotter pins: After you insert the pin through the hole, bend/separate
the tines so they form an angle of about 30 degrees between the two tines.
Next, clip them off to the appropriate length. Next then bend the very end
(1/8" or so) of one tine to about 70 degrees. Finally, tape the area with
rigging tape. Do not bend the tines out 90 degrees right next to the hole.

*Do not use bolts with threads such that a tang, toggle or thimble can rub
against the threads. Use a bolt with a smooth shaft anywhere another fitting
will rub against it. You can bolts of all descriptions at chandleries. The
only place he recommended using a bolt on my P19 was where my head stay
attaches to the tangs on the mast of my P19. ( A note on mis-matched
diameters: The tang had a smaller diameter hole than the toggle, which
required use of a bolt that was too small for the toggle hole, so Bruce made
a sleeve to go around the bolt where the bolt goes through the toggle.)

* Most places, I use rings without extra bends in them, just plain rings.

* On open-body turnbuckles, you can use cotter pins or a single wire, shaped
like a funny "c" that inserts into the holes in both threaded studs. It's
shaped like this:
l l
l __l
l __
l l
l _____l

*Inspect holes in chain plates and tangs for enlargement or elongation. This
can be caused by too small clevis pins or by not strong enough chainplates or
tangs. Replace if there's any elongation of the hole.

*Inspect stainless toggles (like on open barrel turnbuckles) where one SS
part is machined into another. If you see corrosion near the insertion,
assume there is much more inside the insertion and replace the part.
Stainless steel corrodes where is is not exposed to oxygen (chromium + oxygen
= protective patina), so the corrosion is much worse where you can't see it
than where it's exposed to the air. (I replaced all the threaded toggles on
my open body turnbuckles because of this. 8 of them at $8 each. Ouch!)

*Inspect wires for meat hooks and corrosion. Replace any wires that have
"meathooks" (broken wires) immmediately; it has lost at least 10% of it's
strength. Replace any with significant corrosion. Bruce the rigger doesn't
like shroud covers because they block the oxygen and hide corrosion. If you
must use shroud covers, he recommends you use as little as possible and leave
at least 1" uncovered above your turnbuckles so you can inspect them where
they insert into any fitting. That's usually where they fail.

* Don't use hollow body quickpins (with the thumb-push button) at the bottom
of my CDI unit or any other stay. Use a solid shaft quickpin with the little
ball bearings at the end. The hollow body type won't fail, but the shaft can
crush/flatten/distort, making it impossible to pull out. You have to cut
them off with a hacksaw if this happens. Tape the quickpins for stays before
you go out. It's quick and cheap insurance.

*Inspect everything. He gave me a two page list of stuff to inspect
periodically, and a short list of stuff to inspect every time I go out.

I can't think of more stuff at this time, but I'll dig through my junk and
find the written material the rigger gave me about rig inspection, line
selection, wire types and selection, swages vs staylocks vs thimbles, and
recommendations for single handed rigging. I'll post it all on my website
when I figure out a software bug that's bugging me.