Badlad and I were talking about this earlier.
About 30 years ago, he and I climbed a 90m high council incinerator chimney near Nottingham. Our job was to climb it and get it rigged so that in a couple or three weeks time, when the incinerator would be turned off, we could carry out a full internal examination of the stack by rope access.
The incinerator was running when we did the climb, over a couple of days if I remember. The view from 10m from the top was spectacular. We were surprised to see a 10m missile propped up against a wall in some ex-military equipment supplier near the bottom of the chimney. It turned out to be one of the famous Anchor Supplies depots.
We didn't buy the missile as it wouldn't fit on top of our van but Badlad did buy 8000 AG3B flash bulbs. He's probably still got a few left.
Back to the climb. Ropes were attached with Faders Offset D alloy carabiners. These were standard issue for personal rope access kits at the company we worked for. These were subsequently attached to steel Petzl hangers that we had installed to do the climb. We had chosen alloy carabiners for the climb as they were much lighter than the steel carabiners the company usually issued for rigging purposes.
The next time we went to the top, no more than 3 weeks later, the Faders carabiners were very badly corroded. Not quite as bad as in the example photos, but enough to always remember not to leave dissimilar metals connected to each other for long periods, particularly at the top of an operational incinerator stack.
I've got a couple of Clog carabiners that are well over 40 years old that still look and operate like new. They would certainly pass a Thorough Examination.
Mark