I recall reading in a DIY magazine about a proposal to adopt what we would now call TNC wiring, in order to save copper.
Neutral and earth combined up to the fixed light or the socket outlet, though still 3 core flex to appliances.
The risks of a broken combined neutral/earth conductor were noted. To alleviate such risks it was proposed that at the distant end of each radial circuit, that this conductor be connected to any of the following.
1) The CNE of another circuit.
2) A metallic water pipe
3) Structural metalwork.
4) An earth wire installed for the purpose.
Sounds all a bit dodgy, and obviously was never adopted, but was this ever a serious proposal, or was it a rather involved April fools day prank ?
Late 1970s IIRC.
I am aware of concentric wiring* which was what we now call TNC, being used on private supplies, and sometimes misused on public supplies, and I am aware of the practice of "earthing" to the neutral in some places, but neither of these is the same as the proposal that I recall.
*I took out a load of concentric wiring in about 1978, Formerly a 110 volt DC private supply, but later connected to public mains.
