Hi Pauluk.
Yeah, Sweden / UK may have more things in common than Sweden / US . Much thanks to the EU I think. About the pipes. We uses “conduit’s” ( OPG-Pipes they are called here and can be built together by using pre-fabricated bends and seams) as well to protect wiring from mechanical damage, but like you said mostly in industrial work. I’ve seen some work here in Sweden from the 40’s or 50’s where conduits was used for running wires on the outside of walls.
In concealed residential wiring from the 40’s and 50’s maybe even some part of the 60’s they used something called “panzer pipes”. Junction boxes and boxes for light switches and sockets (I don’t think they are called boxes but I think you know what I mean) where also made of metal. One time I was searching for a electric fault in a house built in the late 50’s. My test instrument had probes which was not completely insulated. I had placed one probe on a live (240V) and was just about to remove it when it accidentally touched the box. BAM. The box was in some way, through the pipes, connected to ground. I don’t think the pipes or the box was grounded by intention it was more likely a coincidence.
