[Alberg30] Lightning Protection

[R.C. Alley]

A few years back, the CBA30ODA summer cruise visited (if memory serves)
Urbanna, VA for the fireworks over the 4th of July.  Great fireworks, made
more so by the thunder& lightening which occurred more or less
simultaneously.  Anchored less that 10 meters off a T dock, we got to see a
boat on the dock take a direct hit on its mast by a relatively large
(perhaps because it was close) bolt. For about a second, the boat's
(presumably) radio antenna glowed bright orange, and then disappeared.
That, to the naked eye, was all the hard damage that the boat suffered.
Since we did not subsequently visit the boat, I have no idea what its
internal grounding (if any) was, or what other damage she might have
suffered.  I can say that the boat suffered no hull damage, as it was
sitting properly on its waterline in the morning.

Technical issues aside, it seems to me that this is, at least in the
Chesapeake, little more than an exercise in the laws of probability.  Of the
literally hundreds of boats in the harbor during this storm, only one hit
occurred; there were literally dozens of boats within a 20 meter radius of
the strike, including the boat I was on.  Some were occupied, some not; some
had electric's on, some not, etc.  If this strike was in fact random, then I
see no need to install "lightening protection," as the chances of being hit
are so poor to begin with that it would be a poor use of resources.

I was actually thinking about this last night, in Colorado Springs. I got to
see a truly magnificent storm, at dusk, against the Front Range--best
lightening display I have ever seen.

RA
----- Original Message -----
From: "Helmes, Gail S." <gail_s_helmes at md.northgrum.com>
To: <public-list at alberg30.org>
Sent: Friday, July 12, 2002 9:26 AM
Subject: [Alberg30] Lightning Protection


> While Encore is still out of the water and the mast is down, I am thinking
> about adding lightning protection that would include a grounding plate on
> the bottom of the hull.  We have read up on Nigel Calder,  and have found
> some good Web sites, but would like to hear some experienced opinions.  A
> survey of the local boat yard indicates that most boats don't have
lightning
> protection, but if we are going to do it, now is the time.  Any thoughts
on
> whether to add it?  Any advise on how to do it?  Does anyone wish they had
> installed it?
> Your comments are appreciated.
>
> Gail Helmes
> Encore US 11
> Annapolis, MD
>
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