Over the past six days the WCML has suffered five separate incidents of power lines coming down, causing heavy delays for thousands of passengers.
The most recent took place at 9pm last night in Kenton, Hertfordshire, when powerlines fell from their catenary to strike a Virgin Trains Pendolino service, forcing the cancellation of all trains to and from London Euston until 10am this morning.
Reports by the BBC have suggested that the successive faults may be linked to the higher speeds trains are able to travel on the line thanks to the WCML upgrade.
However, a Network Rail spokesman denied this, telling NCE that all five failures were being treated as separate incidents,with no underlying cause evident.
Prior to last night's incident, the WCML had be closed last Friday due to a light aircraft crashing in to overhead power cables in Staffordshire. This was followed by powerlines falling on to the track in Watford in the early hours of Monday morning, plus lines coming down in Nuneaton, Warwickshire and Bletchley, Buckinghamshire on Tuesday.
The causes of the failures in Watford, Bletchley and Kenton are as yet unknown to Network Rail investigators.
However, the track operator is blaming (as yet unnamed) electrical contractors for the failure at Nuneaton, who were in the process of isolating the overhead lines for maintenance.