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Terry K Terry K is offline
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First recorded activity by BoatBanter: Jul 2006
Posts: 41
Default Emergency lightning protection

The resistance profile may reveal that the shroud becomes the main
dissapative element in the discharge path. It may well vaporize, and
you at sea with sails in a squall?

Every earth bond will include a weak link, which will burn out first,
causing x-metal vapour arc to be temporarily included in an
established hi current stroke discharge, if the bolt be juicy enough.

I would not want it to be a shroud which parts, possibly leaving me a
pedestrian.

Ground the base of the mast as directly as possible to a bare keel or
clean plate, keeping in mind you must plan a fusible weak point
somewhere, but hopefully not where it will cause the mistress to burn
her bum.

My weak point is the four smallish bolts penetrating the overhead at
the tabernacle.

My backup is that the shrouds should position the mast heel adequately
should all four bolts get burned off.

My proof is 25 holes burned in the old mast, repetitively struck by a
biggie. The path presented it's main resistance effect in two distinct
areas: The burn craters in the mast surface, strangely all at the
same point of curvature on the mast surface, and the keel bolt, which
cracked the fiberglass around it's bedding, to the tune of a new leak,
about one drop every five minutes. The bolt is fatter stainless than
the copper ground wire.

I would not want to be making connections grounding equipment once the
storm gets close enough to make it seem an urgent neccessity, I would
likely better be employed reefing or something. Then, I'll go below
and sit under a grounded umbrella, hugging the rum bottle and
whistling for a taxi.

I would have disconnected the VHF AE, but then the steaming lamp would
not work, besides I wasn't there at the time and had not thought to do
so when I left the boat at the dock.

No need, I suspect because the VHF survived the lightning stike.

Terry K