Lightening Protection

[Close hauled]

As the originator of this post I've learned four things:

1 Lightening is spelt LIGHTNING

2 Lightning strikes are very injurious to your boats electronic systems. ie totally wipes them out.

3 Putting things in the pressure cooker or oven worked in our case.

4 My friend Buddy from New Oreans says 'Man, its all voodoo'.....

 

[TonyD]

Check out Ewan M Thomson's web site . I have no idea whether this guy knows what he's talking about, but his web site seems to carry some authorative articles on lightning protection for boats.

Isn't Google wonderful!!!

TonyD

 

[Close hauled]

Yes, he is Mr Lightning isn't he?

Everything I've read comes down to the same thing - make sure you've got a very good ground.

 

[raven]

So my steel hulled boat should fit the bill then?

Presumably it should dissipate a strike down the mast and rigging through the hull and water to ground? /forums/images/graemlins/confused.gif

 

[ianabc]

I thought that the purpose of the device shown in the web page link is to disapate/bleed off the ions before the strike.

Ultra high speed photography has swhown that before the down strike, there is a stream that goes upwards.

The wire stainless wire brush type devices (Forespar makes one) is designed to dissapate before the down strike and therefore does not in theory carry the extreme charge as it avoids the down strike.

 

[Cruiser2B]

I think video has shown the 'stepped leaders' and 'spark attachments' (upstrikes). As I said before, I don't think those brush type devices dissipate the charge, so much as they disrupt the formation of the 'spark attachment' (or 'upward feelers'). Just my personal theory. I think you're pretty safe in a steel boat. Don't know if some form of surge protection is warranted/advised. Anyone?

 

[peteandthira]

I would suggest a steel boat being safest. There should be a healthy path to earth. However, if it does get struck you will STILL have those 20000A flowing down from the top (actually up from the bottom) which via Ohms Law will produce unavoidable high voltages increasing with height of metalwork. These high voltages can jump adjacent gaps onto yourself or any other boat item. In addition, induced voltages in nearby wiring will still probably fry delicate electronics. Inside the hull I would expect reasonable protection from the latter if your decks are steel as well (Faraday Cage).

Aircraft are rarely damaged by lightning (Faraday Cage) but can often suffer compass or avionics problems as a result.

 

[Close hauled]

Nigel Calder has some interesting stuff in his 3rd edition