"Peter Able" wrote in message
...
On 16/04/2021 15:57, NY wrote:
I'm used to seeing three-wire (three phases) overhead mains wiring from
poles along a street. Sometimes you get four-wire (three phases plus
neutral). Modern wiring is a single larger cable which is the three (or
four) wires twisted together. In each case, two wires (between two
phases, or one phase and neutral) go to each house, with a different
phase for each house or group of houses.

But I'm mystified about five-wire mains. As far as I could see, all five
wires were the same thickness and were each fastened to the same type of
insulator on the wooden poles - so probably not three-wire mains and
telephone.

What would the fifth wire be used for?

Telephones - well it is around here.

With the phone wires on (as far as I could see) the same brown porcelain
insulators as the 240 V mains wires?


This is the wiring https://goo.gl/maps/7TY9tJ2LNZfzEGE46 and
https://goo.gl/maps/YRgYsyz7K75p3KUZ6: the latter shows a separate phone
wire swapping from below the five mains wires on the nearest post to the
above them on the next post, which looks as if it could cause if the
insulated phone cable was repeatedly blown against the un-insulated mains
wires, eventually taking the phone insulation off and shorting the mains
wires.