Lightning Strikes and The Faraday Cage

[Paul Arden]

Anyway if lightning never strikes the same place twice then I’m quite safe. Hit my roof last year and took out our broadband internet.

[Lasse Karlsson]

That's a myth though.. Lightning takes the path of least resistance, and where it just hit is usually that

Cheers
Lasse

[Limpe Iven]

Ok so sit in the middle of the boat. Would touching the hull be a problem?

yes. sudden death. no matter where the impact occurs on your faraday's cage.

You want the electricity to be lead away the fastest possible way.
Lightning will probably hit the highest point of the boat, a thick low resistance wire would be best to guide the electricity away from the metal structure.
eaxmple, a high point to catch the lightning bolt, guide it trough the lowest point of the boat (or a connection with the water) with an insulated low (but thick) resistance wire, preferably to a large surface under the boat insulated from the hull.

You'd be surprised what a lightning strike can do to relative thin aluminum ( i work with skyjacks, have seen aluminum telescopes after a lightning strike, big, big holes where the power discharged... not an option in boat, i guess).
Faraday's cage is only safe if the person or object is within and insulated from the cage.

Also, bare aluminum will oxidize, immediately when exposed to air, it grows a "skin" (ask your welder, he knows) wich has a higher resistance than the bare aluminum underneath, another potential hazard.

As for the faraday's cage usuablity on a boat,a microwave on rubber feet will work as one, during thunder and lightning it could help getting your electronic devices safe by putting them inside.
Also, mount a mainswitch to disconnect battery from any electrical device (gps, fishfinders, scanners, radio, your engine's ECU) so when in doubt you can swith it off. The voltage of lightning will kill any appliance with a low resistance.
Unfortunally, most device will be grounded to earth, in this case the hull, wiring-wise it would be difficult to disconnect them all with the flick of switch.

For electricians that work on high power/high voltage installations there are special rubber insulation mats gloves and boots available, i'd go for something like that to be on the safer side.

Put some shoes on.

[Limpe Iven]

That's a myth though.. Lightning takes the path of least resistance, and where it just hit is usually that

Cheers
Lasse

with a brick house yes, an aluminum boat is whole different game.

[Lasse Karlsson]

That's a myth though.. Lightning takes the path of least resistance, and where it just hit is usually that

Cheers
Lasse

with a brick house yes, an aluminum boat is whole different game.

So with an aluminium boat it will only hit it once?
Why is that, did the boat disappear?

Cheers
Lasse

[Limpe Iven]

i misread.. was referring to the cage thingy.
come to mention, houses don't have the tendency to move a lot, boats mostly do.
So as for probability, the house has a higher rating, especially the ones that are stocked with carbon rods

[Paul Arden]

So... sit in chairs, feet up and drink beer? Perfect!

I’ll look into a lighting rod insulated from the roof and earthed and insulated from the hull to below the waterline.

Two Orang Asli got struck from one of the villages last year, so it’s something I’m taking seriously.

Cheers, Paul