I read that article yesterday, and wondered exactly what they are calling a "pylon" since none of the news sources had a picture, found out that steel structures are also called electrical pylons. Here in the US, steel structures are usually limited to transmission voltages, dunno about in Scotland.
However as an aside, I did find out about the really cool Pylons of Cádiz, a pair of very cool-looking steel structures supporting two 132 kV circuits crossing the bay of Cádiz, Spain.
True for Austria too, but just across the iron curtain I've seen my fair share of 10 or 20kV on steel lattice poles. Railway distribution (15kV 16.7Hz) favors those too, especially in Germany and Switzerland. Austria switched to concrete decades ago, but there are still plenty of old steel poles around. 50Hz distribution seems to use steel poles for 110, 220 and 380kV.
Back in the 50's, old rail tracks were welded up make a pole for 11kV lines in rural areas, you can see them here, rusting away in our harsh weather conditions. No galvanising, steel cross-arms and pins for the insulators. I have an idea that the Railways (before they were sold off) sold all their scrap to the PoCo and this ended up as power poles, with cheap 1" angle section to brace the two up-rights
Now, we have problems with either the welds failing or general corrosion, this was not a good plan.
No engineer worth their salt would ever have bare metal out in the elements, but I suppose they were cheap.