On Fri, 8 Feb 2019 15:54:19 -0000 (UTC)
Anna Noyd-Dryver wrote:
Marland wrote:
Or use twin conductors like a trolley bus.
There was a short section In Greenwich when the Royal Observatory was
still located there where stray current even from normal track would have
affected some instrumentation.
They were rare though and I don’t immediately recall another UK
installation.
Having gone to the trouble of avoiding overhead returning a few years later
and putting up twice as much would hardly be popular.


That would necessitate use of trolley poles, where pantographs are the
current standard fitment for new tramways.

I suppose you could have twin pantographs as fitted for 3-phase on certain
mountain railways, though you might get polarity issues on single track

Install a bridge rectifier in the trams. Problem solved.