[Rhodes22-list] The great lightning debate.

Ronald Lipton rlipton at earthlink.net
Mon Dec 6 15:48:55 EST 2004


I  think that we agree on this.  The most important
thing to do is stay away from contact with metal
parts of the boat during a storm.  Overall, the risks
due to lighning strikes on a small boat do not justify
the significant effort and small chance of positive
effect of grounding the mast and rigging.

Take a look at:
http://www.thomson.ece.ufl.edu/lightning/
He has studied lighting protection for boats and concludes
that the existing code requirements are inadequate for
a significant strike and recommends #4 gauge wire
and concludes that you can't effectively shunt the
current at all with a reasonably sized plate in fresh water.

Ron
----- Original Message ----- 
From: "Richard Smith" <sailnut at worldnet.att.net>
To: "The Rhodes 22 mail list" <rhodes22-list at rhodes22.org>
Sent: Monday, December 06, 2004 2:29 PM
Subject: Re: [Rhodes22-list] The great lightning debate.



< The best it can do is shunt the current to the water rather than
> though your electronics, rigging, and you.>

Impossible...!  The amperage from a lightning strike would be measured in 
hundreds if not thousands of amps.  The notion of conducting this kind of 
power to the water is totally flawed.

In the past his subject has been addressed by me (I am a graduate 
metrologist) and others.  The long and short of it is that setting up a 
grounding system MAY be better then nothing and that's about it.

Probably the Catalina described was struck because (of the grounding 
installation) it offered the path of least resistance to the water.

It can not be stated to often;  THERE IS NOT ONE INSTANCE OF ANY ONE ON A 
SAILBOAT BEING KILLED BY A LIGHTNING STRIKE!!!  Yes their have been injuries 
arising from several eventualities associated with a strike but no deaths.

Richard Smith

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