UK: Infrastructure manager Network Rail says it has reduced the amount of copper needed for signalling power supply projects by a third through a three-year project to enable two-core unarmoured class 2 cables to be used in place of armoured class 1 cables containing two live wires and an earth wire.

'The whole system of power transmission had to be redesigned, from the transformers to the switchgear', according to Mark Southwell, director of NR's IP Signalling Programme.

'Normal three-core cable has steel strands wound through it to protect it from rodent damage and other hazards, which also means that any fault will find its way to all the equipment it connects. A new form of armour had to be developed, along with double or reinforced insulation for signal housings and switchgear.'

Enhanced mechanical protection is provided by fibre weave, with integrated identification features to deter theft.

Suppliers involved in the project

Transformers and rectifiers

Signalling Solutions, Invensys, Trans-Tronic

Power cable

Cleveland Cable, Anixter Cable, Eland Cable, Apex Cable

Low-voltage switchgear

Schneider Electric, CSE, Henry Williams, Ilecsys, MGB, Traix

Auto reconfiguration systems

Kelvatic, Schneider Electric