[Public-list] Lightning Protection

[George Dinwiddie]

Thanks, Mike.  I'm still trying to get the old message archives.

I did some in-depth study of the problem, some years back.  Even if 
you're not concerned with direct hits, there are significant problems. 
For one thing, you need *at least* 2 square feet of clean copper in the 
water to begin to have a grounding system that will do any good at all. 
  Any electrostatic discharge system should be grounded to that, and 
isolated from the through-hulls.  There have been many incidences of 
through-hulls being blown out of the boat because of bonding or 
grounding.  You also need a fairly straight path with a heavy conductor 
from the air terminal to the ground.  Unless you have an exposed lead 
keel and a keel-stepped mast, the difficulties are overwhelming.

Even then, it's not clear that grounding is the best idea in all 
circumstances.  If I'm going to take my chances, anyway, I'll do it in 
the fashion that requires less work.

  - George

Michael wrote:
>>I started thinking about lightning protection.
> 
> <snip>
> 
>>Does anyone else worry about this?
> 
> 
> Yes. I was going to direct  you to the archives-the subject was covered in
> detail a year or so ago. It doesn't look like the archives go back that far,
> so...
> 
> I think George Dinwiddie had the best summation, if I may paraphrase him
> from memory: there is no reasonable safeguard from a direct lightning
> strike, there is simply too much energy involved. you can play around
> ameliorating stray currents, but it is possible that by having a ground, you
> will attract those strikes more than if you had no ground at all.
> 
> Not much help, I know, but nature is an awsome beast. Sometimes you just
> have to take your chances.
> 
> Michael Grosh
> Checkmate #220

-- 
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   When I remember bygone days                         George Dinwiddie
   I think how evening follows morn;            gdinwiddie at alberg30.org
   So many I loved were not yet dead,           http://www.Alberg30.org
   So many I love were not yet born.
                                             'The Middle' by Ogden Nash
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