@ BS,
When chasing one of many faults on this infamous overhead run I accompanied the engineer who was making a forlorn but valiant attempt to cure our vary nasty noise problem.
This is the first o/h section of the lines.
I know that the unit is connected via a 50 pr (I think) cable to an u/g joint which has a .9 mm u/g feed from across the road and the outgoing 0.5 mm catenary cable.
At that time the earth wire was neatly coiled up under the unit indicating that it was no longer in service.
I suggested the engineer cut this away in case it was acting as an aerial but to no avail.
The engineer then opened the u/g joint to discover most, but not all, twisted pair gel crimps had three wires in them indicating that there was a tap configuration still in cct.
I do not know, but I strongly suspect, that some ccts still have tap connections although the engineer did remove the tap section for "our pair".
The engineer suggested it would take about 2 - 3 hours to remake the joint properly so we did not hesitate in beating a hasty retreat !
Kind regards,
Walter