Originally Posted by Adelie
I work in construction as a structural inspector. For one particular type of construction, post-tension, high strength (270ksi) wire is used. On of the big no-no's with PT cables
is for welders to hook their ground to the tendons when welding on any nearby rebar or structural steel. The high currents used in welding affect the properties of the cables
. I am unsure if strength is affected or the low-relaxation required for PT construction or some other important property. There is no visible evidence of the damage.
I can't say that lighning would or wouldn't affect stainless rigging
without visibly indicating it, but if it were my boat I would contact the wire manufacturer to see if they had anything to say. I would think that suppliers and rigger might have the info, but they also might have incorrect info. The manufacturer's metalurgists should know the answer.
Don't know how rigging
reacts with a massive belt if it can't earth, maybe momentarily overheat?. I had a custom built Masthead Cutter
made from "Corten Steel" developed to eliminate the need for painting and form a stable reddish rust-like appearance when exposed. A rusty-looking tower block in Leeds (Met University Tower) is made from it. Nevertheless, as the hull
& topsides were virtually sheathed more for appearance (won't take up more space here) and on a metal boat the rigging to the steel chain-plates in theory should act as a ground, I still had concerns about Lightning
Strike & how the Bolt would earth. I have always felt very vulnerable in the middle of an ocean during a lightning
storm with my little Metal Stick being the only grounding rod sticking up in the vicinity. I got a heavy duty copper braided cable and linked it from the mast
through to the rudder
post & Anodes. Don't know if it did any good but I felt a tad more secure knowing it was there. Subsequent to that, when I had a GRP boat, because the keel
wasn't encapsulated I was able to repeat the exercise through to a keel
bolt but fortunately never had occasion to find out if it worked.