[Rhodes22-list] Forestay Wire Size Upgrade

Tue Jun 3 23:03:19 EDT 2003

Good point Roger.

Razz

-----Original Message-----
From: rhodes22-list-bounces at rhodes22.org
[mailto:rhodes22-list-bounces at rhodes22.org]On Behalf Of Roger Pihlaja
Sent: Wednesday, June 04, 2003 4:06 AM
To: The Rhodes 22 mail list
Subject: Re: [Rhodes22-list] Forestay Wire Size Upgrade

Razz,

I took the following quote from your recent post to Bob, "It's OK to go up
one size on the wire, but you will not be able to properly tension a larger
wire without overloading the rest of the rig."

This statement is FALSE!  Forestay sag is not a function of wire size.  i.e.
a 1/8" OD, 3/16" OD, & 1/4" OD forestay rigged & loaded in the same manner
will sag the same amount.  If the rest of the rig on Bob's R-22 was capable
of removing forestay sag with the original OD wire; then, it will still be
capable of removing the same amount of forestay sag with the new larger OD
wire.  The smaller OD wire will be tensioned closer to its rated load &
will, theoretically, fail sooner.  But, as long as the wire loading is kept
within the recommended limits, the mean time to failure (MTF) is measured in
millions of hours & hundreds of thousands of cycles.  The larger wires are
simply loaded to a smaller % of their rated load & will theoretically last
for 2 or 3 "infinite MTF's" vs. only one.  None of us will live long enough
to verify it.

Your comments re crevice corrosion & periodic replacement in salt water
service are quite correct.

I think Bob's forestay failure was in the wire itself not the swage.  That's
why I think the wire had been kinked or otherwise damaged.

Roger Pihlaja
S/V Dynamic Equilibrium

----- Original Message -----
From: "David Rasberry" <cinetics at acsinc.net>
To: "The Rhodes 22 mail list" <rhodes22-list at rhodes22.org>
Sent: Tuesday, June 03, 2003 1:59 AM
Subject: RE: [Rhodes22-list] Forestay Wire Size Upgrade

> Bob,
>
> If your forestay failed near the lower swage fitting the most likely cause
> was crevice corrosion from moisture getting into the swage over time. Its
ok
> to go up one size on the wire, but you will not be able to properly
tension
> a larger wire without overloading the rest of the rig.  Static tension on
> the wire is supposed to be between 10 and 20% of rated breaking strength.
> For 1/8" wire, which is standard on the Rhodes, the breaking strength is
> around 2100lbs. 5/32" wire is around 3100lbs, 3/16" wire is 4700lbs and
1/4"
> wire is 6300 lbs. 5/32" is one size up from the rest of the rig, which is
> plenty. One of my old lower shrouds failed under calm conditions with the
> boat at the dock. There was no visible damage or discoloration or other
> obvious outward sign of deterioration prior to failure. I replaced the
> entire rigging gang immediately. If yours is original to the boat and 10
> years old or more I would recommend the same. If you want to avoid the
> problem of swage failure, get a 5/32" forestay with a Sta-lok fitting on
the
> lower end instead of a swage. they don't make Sta-loks for 1/8" wire or I
> would have used them. Since I don't have a furler, I stayed with 1/8" on
my
> gloucester. I used Sailing Services of Miami for the new rig. They pack
the
> swage fittings with an anti-corrosion grease before compressing them onto
> the wire and use a rotary hammer press that produces a tighter fitting
swage
> than the usual Kearney roll swaging press without deforming or cracking
the
> swage fitting.  SSM specializes in rigs for boats that spend their lives
in
> tropical salt water areas, so they use a premium grade wire alloy and
> fittings and take extra measures to maximize corrosion resistance. If you
> are in a rush, Riggers Supply in Greenville can make a new one up for you
> while you wait if they are not too busy. They do mostly heavy gauge
> industrial rigging like cranes. They use a Kearney roll swager for smaller
> stuff. You might have to supply your own end fittings since they don't
stock
> marine hardware. They do have the wire though.
>
> Razz the Gloucester sailor
>
> Hi Rhodies, its been a while since I have been active due to family
> circumstances, though I have been catching up on the list backlog every
once
> in awhile. PS Bob,Ed and Rummy, my sister gave me a Loos tension gauge for
> Christmas, so if you want to tweak your rigs just holler.
>
> -----Original Message-----
> From: rhodes22-list-bounces at rhodes22.org
> [mailto:rhodes22-list-bounces at rhodes22.org]On Behalf Of Bob Keller
> Sent: Monday, June 02, 2003 8:20 AM
> To: rhodes22-list at rhodes22.org
> Subject: RE: [Rhodes22-list] Forestay Wire Size Upgrade
>
>
> Roger & Rummy,
> Could I super-size the stay by drilling a larger hole in the roller furler
> drums?  Or would it be better to leave well enough alone and keep the size
> the same.  I thought that I had 1/4" wire, but you (Roger) said that you
> increased the size up to 3/16"  I'm confused (as usual).
> Bob K
>
>
> >From: "John Tonjes" <johntonjes at earthlink.net>
> >Reply-To: johntonjes at earthlink.net,The Rhodes 22 mail list
> ><rhodes22-list at rhodes22.org>
> >To: "The Rhodes 22 mail list" <rhodes22-list at rhodes22.org>
> >Subject: RE: [Rhodes22-list] Forestay Wire Size Upgrade
> >Date: Mon, 2 Jun 2003 08:54:33 -0400
> >
> >Roger,
> >Thank you. We tried to convince Captain Bob that the wire broke due to
> >operator error and you helped to reinforce our opinions. Sometimes it's
> >hardest to see the forest through the trees.
> >
> >Rummy
> >
> >
> > > [Original Message]
> > > From: Roger Pihlaja <cen09402 at centurytel.net>
> > > To: The Rhodes 22 mail list <rhodes22-list at rhodes22.org>
> > > Date: 6/2/2003 7:43:57 AM
> > > Subject: [Rhodes22-list] Forestay Wire Size Upgrade
> > >
> > > Bob,
> > >
> > > When I upgraded my roller furler from the stock GBI unit to a Harken
> >Unit
> >0,
> > > I increased the forestay wire size from 5/32" OD up to 3/16" OD.  I
made
> > > this upgrade because 3/16" OD was the largest wire size that would fit
> >the
> > > Harken Unit 0 and the differences in cost, weight, & windage were
> > > negligible.  There was a significant upgrade in safety margin as the
max
> > > tensile breaking strength was increased by about 35%.  Just make
certain
> >the
> > > end fittings use the same size pins as you have now.  Before you make
> >this
> > > change in wire size, be certain your OEM roller furler can handle it.
> >My
> > > guess is that it will not be able to work with the larger wire OD.
> >There
> > > probably won't be sufficient clearance for the mechanism to turn
easily.
> > >
> > > It is rare that a wire rope will simply fail W/O any warning in the
> >middle
> > > of its length, especially in light air.  Most the time, progressive
wire
> > > rope degradation or imminent failure can be detected by inspecting the
> >wire
> > > visually & running your hand or a cloth along it.  Single strand
> >failures
> >in
> > > a wire rope usually show up as curled "meat hooks" that you will feel
> >with
> > > your hand or will snag a rag.
> > >
> > > It is especially important to inspect the fittings at the ends of the
> >wire
> > > rope.  Look for tiny cracks &/or discoloration (usually rust or black
in
> > > color) in the fitting or the wire near the fitting.  If you see any
> >cracks
> > > or discoloration; then, immediately take the piece to a rigging shop
or
> >just
> > > simply replace it.
> > >
> > > Your post implies you suspect your forestay was somehow getting
> >repeatedly
> > > kinked just below the bottom of the furling drum as a result of the
> > > trailering process.  If this is the case; then, you need to change
your
> > > trailering &/or mast stepping procedures.  In thousands of trailering
> >miles
> > > & dozens of mast steps since 1987, my forestay has never been kinked
as
> >a
> > > result of trailering or mast stepping.  If your forestay was getting
> > > repeatedly kinked in the same spot, this would be very bad for the
wire.
> > > Upgading to a larger wire size will do little to fix this problem.
> > > Stainless steel wire rope is not very tolerant of kinks.  So, if your
> > > trailering &/or mast stepping procedures are causing the forestay to
be
> > > kinked; then, figure out some other way accomplish the same task W/O
> >kinking
> > > the wire.
> > >
> > > Good luck, Bob!
> > >
> > > Roger Pihlaja
> > > S/V Dynamic Equilibrium
> > >
> > >
> > > ----- Original Message -----
> > > From: "Bob Keller" <r22yankeeclipper at hotmail.com>
> > > To: <rhodes22-list at rhodes22.org>
> > > Sent: Sunday, June 01, 2003 11:32 PM
> > > Subject: [Rhodes22-list] Frigging Rigging
> > >
> > >
> > > > While sailing today on a rather calm day on Lake Hartwell, my latest
> > > > calamity was that my forestay broke.  Yep, it broke off right at the
> > > bottom
> > > > of the furler drum.  Could have been worse because Roger R shinnied
up
> >the
> > > > mast (amazing thing to see) and tied a line just above the spreaders
> >which
> > > > we secured to the bow cleat to keep the mast from going too far.
> > > Meanwhile,
> > > > Rummy was mixing drinks below, oblivious to the goings-on up above.
> >We
> > > > motored back from Big Water and dropped the mast.
> > > >
> > > > Looks like the forestay was bent too many times, possibly from
> >trailering,
> > > > and it finally gave way.
> > > >
> > > > It was recommended to me to upsize the forestay to 5/16" (by the
same
> > > people
> > > > who told me to pull my diamondboard  down all the way unti lit is
> > > > perpendicular to the boat!).  Does anyone have experience or
knowledge
> >of
> > > > using a slightly larger stay?  Any problems to be aware of?  Sounds
> >like a
> > > > good idea to me, but I wanted to check the list to see if anyone has
> >done
> > > > this before?  Thanks.
> > > > Bob K
> > > > s/v Yankee Clipper
> > > >
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