Not pre-galvanising at all, that process dates from long before any of us was born (and by the way, it's actually hot-dip galvanised - a misnomer - rather than electro-plated.) All the original electrification hardware was very carefully planned/specified, with "galvanised" steelwork protected by a carefully-chosen paint system that would (if maintained) have kept the galvanised steel safe for ever. The other bits (the tubular steel supports) were also a bit special, being physically copper-clad, but they stood the test of time. Apparently the procurement was a bit fraught but a few of them are still around, clearly identifiable by their bright turquoise colour. I worked with a man who was involved in setting it up.Pre Galvanising. Just paint. And asset policy has changed from wholesale repainting to patch only when corrosion appears.
These structures are in an awful location to inspect unforunately, probably why it's got this bad...
Agree about the difficulties of inspection/maintenance though.
I'm not surprised to hear this!Heavy duty damage. All the zinc from the galv is long gone. Moisture and dissolved salts from rocks has exacerbated the corrosion. Expect all 1950s and 60s structures across the network to get an inspection this year.