PASSENGERS spent almost two hours on a train after problems when it entered a a tunnel this morning (Wednesday).
The 7am Tring to London Euston service had to be stopped for safety checks and came to a standstill after exiting the tunnel at Northchurch.
London Midland spokesman Mike Dalton said: “There were reports of a train entering the Northchurch tunnel and being struck by something, but that is not exactly what happened. There was ballast thrown up and the electricity supply tripped.
“Nothing has been found untoward, but there is a train we need to remove from the line.
“Network Rail have been investigating the line, but it has meant delays to trains to Euston.”
Some services operating between Tring and London Euston have already had to be cancelled and Mr Dalton said trains are likely to be disrupted until later this morning.
Network Rail spokesman Russell Spink said: “There has been some superficial damage to the overhead line.”
He recommended that rail users visit www.nationalrail.co.uk for the latest travel updates.