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.