Ralph, I hadn't seen this link, and I thank you for it. <<Lightning is a capricious, random, stochastic and unpredictable event>>
This makes me rethink my already-rethought position... I'm going to go after some of the sources quoted by the author of this document, especially the one mentioned regarding the ineffectiveness of 'air terminals' in protecting a structure (which is what I was attempting). I do note that he suggests alternative protection--shielding wires above a structure, like our shrouds... But I'm not too happy with the idea of having all the conductive leads outside my hull all the time. Drag, maintenance, appearance... it's just about enough to make me go all the way back to my original plan, which was to stay isolated from ground. Darn... And if I switch to solid copper strapping inside the hull from all the shrouds and lifelines and mast, I'd be adding a lot of weight to what's already a really heavy boat (anchor chains, 7 batteries, inboard engine, beefier rigging, etc.) Rats.
This makes me rethink my already-rethought position... I'm going to go after some of the sources quoted by the author of this document, especially the one mentioned regarding the ineffectiveness of 'air terminals' in protecting a structure (which is what I was attempting). I do note that he suggests alternative protection--shielding wires above a structure, like our shrouds... But I'm not too happy with the idea of having all the conductive leads outside my hull all the time. Drag, maintenance, appearance... it's just about enough to make me go all the way back to my original plan, which was to stay isolated from ground. Darn... And if I switch to solid copper strapping inside the hull from all the shrouds and lifelines and mast, I'd be adding a lot of weight to what's already a really heavy boat (anchor chains, 7 batteries, inboard engine, beefier rigging, etc.) Rats.
I wish I had a poem to lighten my spirits...
Thanks so much for your input. I have, by the way, read Thompson's book and agree with you... The book that convinced me about bonding is another one, focused on marine electrical systems, and offering a lot of the principles of the ABYC; I thought I'd avoid insurance issues and gain an advantage on my eventual resale of Pixie if I just followed what ABYC wanted. What a tough decision...!
David Shaddock
as confused as I've ever been--but more educated now....
----- Original Message -----
From: "Ralph E. Ahseln" <[EMAIL PROTECTED]>
Date: Saturday, July 15, 2006 11:04
Subject: Re: RE: catalina27-talk: Lightning
To: [email protected]
> See the following:
> http://www.lightningsafety.com/nlsi_lhm/explosives.html
> Particularly the sentence in the Abstract,
> " Franklin's 1752 lightning protection invention consisted of a
> rod in the air, one in the ground and a connecting conductor.
> This "conventional wisdom" today is helpful for fire protection
> in cases of direct flashes to ordinary structures. For more
> complex facilities, where electrical systems/electronics or
> explosives or volatile substances are present, the 248 year old
> design is questionable
> "
>
> I might add. Item.. 4.2 says a
> lot.. Why would anyone want to conduct the stuff INSIDE
> your boat..
>
> Our boats are rotten Faraday cages..
>
> David, I suspect the book you've read is by the (IMHO) the
> infamous Dr Ewan Thompson supposedly from the U. of Florida..
> I would take what he has to say with a VERY big grain of salt.
>
>
> UW,
> Ralph Ahseln
> Oblio
> Gresham OR
>
----- Original Message -----
From: "Ralph E. Ahseln" <[EMAIL PROTECTED]>
Date: Saturday, July 15, 2006 11:04
Subject: Re: RE: catalina27-talk: Lightning
To: [email protected]
> See the following:
> http://www.lightningsafety.com/nlsi_lhm/explosives.html
> Particularly the sentence in the Abstract,
> " Franklin's 1752 lightning protection invention consisted of a
> rod in the air, one in the ground and a connecting conductor.
> This "conventional wisdom" today is helpful for fire protection
> in cases of direct flashes to ordinary structures. For more
> complex facilities, where electrical systems/electronics or
> explosives or volatile substances are present, the 248 year old
> design is questionable
> "
>
> I might add. Item.. 4.2 says a
> lot.. Why would anyone want to conduct the stuff INSIDE
> your boat..
>
> Our boats are rotten Faraday cages..
>
> David, I suspect the book you've read is by the (IMHO) the
> infamous Dr Ewan Thompson supposedly from the U. of Florida..
> I would take what he has to say with a VERY big grain of salt.
>
>
> UW,
> Ralph Ahseln
> Oblio
> Gresham OR
>
