CORROSION failure of the droppers supporting 25 kV 50Hz contact wires has been a cause of delays to trains on Network Rail’s East Coast Main Line.

The engineers responsible for overhead line maintenance are now using a tool that allows a man standing on the track to replace droppers on live wires.

The tool is fixed to the end of a standard insulated pole normally used to apply an earthed wire to the overhead wires after power has been isolated. Clamped to the contact wire, it allows the operator to remove the failed dropper and install a replacement.

Taking an isolation in the normal way can close the line for up to 4h, needing a hydraulic platform or scaffolding. The tool enables staff to go to a site where a dropper failure has been reported, then replace a failed dropper in as little as 5min.

Network Rail, UK