Received: from hpoclrf.sj.hp.com by opus.hpl.hp.com with SMTP (1.37.109.8/15.5+ECS 3.3+HPL1.1) id AA22656; Fri, 20 Oct 1995 08:01:31 -0700 Return-Path: <kirk@hpmsd3.sj.hp.com-DeleteThis> Received: by hpmsd3.sj.hp.com (1.37.109.16/15.5+IOS 3.22) id AA297781286; Fri, 20 Oct 1995 08:01:26 -0700 Date: Fri, 20 Oct 1995 08:01:26 -0700 From: Kirk Lindstrom <kirk@hpmsd3.sj.hp.com-DeleteThis> Message-Id: <199510201501.AA297781286@hpmsd3.sj.hp.com-DeleteThis> To: poulton@zonker.hpl.hp.com-DeleteThis, wind_talk@opus.hpl.hp.com-DeleteThis Subject: Re: equal time for Fiberspar
In case Neyin reads this.....
I'm "Kirk" and didn't make the show, but I have broken 7 Fiberspar booms
over about 2-3 yrs with maybe 5 in a short time where they'd last maybe
20 good, hard sessions. Then the FE Al got thicker and they lasted
longer, but still failed the same way after maybe 60 sessions. Talking
to some VERY GOOD mechanical engineers I know, I find that making things
thicker where they fail only increases the time until failure....So it
might just make the booms last until the warranty is well past unless
you sail 60 days or more on the boom in the Gorge, Maui or SF Area and
then you see the failure. My observation in Maui and the Gorge is that
most "frequent sailors" use wave sails and don't need an expensive boom
that breaks so they use Chinooks in the Gorge and a hodge-podge in Maui.
So.......the low failure rate outside the Bay Area may mean others sail
less and certainly not in the same difficult conditions where we have to
go against heavy chop to get/stay upwind in flood tides.
Also, I've looked at all the Fiberspar booms that have broken and I've
not seen any sign of corrosion from improper plating. The thick and
thin FE's seemed to have failed the same way looking like a metal tube
that has been worked back n forth until it fails.
my $0.02 worth
...and alot more in boom dollars....8-(
Kirk Lindstrom
ASD epoxy: 8'8" RKT, 8'11" CS & 9'6" no-nose CS; Mistral CFlex & Malibu
Wt 213#, Ht. 6'0", Usually sail on SF Bay, Cailf.
(kirk_lindstrom@sj.hp.com-DeleteThis)
> Nevin's response to my report:
>
> I think your report is reasonable. I should point out that it is
> true that the boom front end failures are most accute in San
> Francisco Bay area. This is a combination of improper front ends
> arriving to SF, the particular chop, and big sails in big winds.
> The warranty rate is no where near 10%-20%, even in SF bay.
> Unfortunately a broken front end is way more dramatic, un-fun, and
> noticeable than all the Fiberspar booms intact that are pleasantly
> sailing around, so it may seem that the problem is bigger than it
> is.
>
>
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