Freezing weather conditions have been identified as a possible cause of disruption to rail services on the West Coast Main Line (WCML) over the last few weeks. Sub-zero temperatures could have been a factor in three key incidents where overhead power lines came down, track operator Network Rail said.
A Network Rail spokesman confirmed that an internal inquiry had been launched into the delays. These occurred at:
Wembley where a fibreglass rod had been installed incorrectly
Watford where metal fatigue had caused a screw assembly to fail
Bletchley where the support for the main catenary cable failed.
In the same period, overhead lines also came down at Nuneaton following a mistake by electrical contractors in the process of isolating them for maintenance. The spokesman said preliminary assessments had not pointed to recently increased line speed as the cause of the accidents, as most of the network had been using increased line speeds following completion of the £9bn WCML upgrade last year.
In addition, two of the locations had not been subject to an upgrade. Mott MacDonald technical director Paul Lambert said he had not seen a detailed break-down of the faults, but: "It is possible that the screw and the wire breaks were aggravated by the recent low temperatures if already compromised in some way." Network Rail confirmed that it would be looking at the effects of the very cold weather.