Simon Taylor

Just enjoying lockdown by restoring an old GPO clock relay unit. I need to take a little care as apparently,
GPOtelephones@... cloth cables were doped with arsenic to stop rats chewing them!

Although designed in 1936, this unit is dated as 1951 being built at the GPO factory, Birmingham. 
Lovely bit of quality wiring.

Simon GPO Clocks

Simon GPO Clocks

John Haine

Could the arsenic story be a ruse to discourage theft?  Like the story that the main benefit of pressurising PO cables was that when a navvy put a pick through one the hiss would make them think they'd punctured a gas pipe and be more likely to report it...