National Rail was warning passengers that some trains could be cancelled, delayed by up to 15minutes or revised as a result of the problem, with disruption expected until at least 10am.
The problem affected numerous operators, including:
Avanti West Coast between Edinburgh / Blackpool North / Preston / Wolverhampton and London Euston
CrossCountry between Manchester Piccaidlly and Birningham New Street / Bristol Temple Meads / Reading / Bournemouth / Southampton Central
London Northwestern Railway between Liverpool Lime Street / Crewe and Birmingham New Street
Transport for Wales between Holyhead / Aberystwyth / Shrewsbury and Birmingham International
West Midlands Railway between Shrewsbury / Wolverhampton and Birmingham New Street / Walsall
CrossCountry passengers were told they could use their tickets at no extra cost on any West Midlands Railway and London Northwestern Railway train between Stafford and Birmingham New Street or any Transport for Wales service between Wolverhampton and Birmingham.
They were also told they should change at Birmingham New Street for another service towards Wolverhampton, while those at the Black Country city were told to board a local train which would "divert around the affected line". They could then continue their journey from Birmingham New Street.
National Rail also said to CrossCountry passengers: "If any services from Wolverhampton towards Manchester Piccadilly are cancelled, please travel with London Northwestern Railway towards Stafford and change for the next available northbound CrossCountry service."