Runaway Tube train: Operators fined £300,000
Three transport companies have been fined £300,000 after a runaway train came within 2,000ft (600m) of crashing into a packed tube train.
The Old Bailey heard how a maintenance wagon broke free from an empty passenger train which was towing it.
It hurtled at up to 30mph for four miles (6km) down the Northern Line, passing through seven stations.
London Underground (LU), Tube Lines Ltd and Schweerbau GMBH pleaded guilty to endangering passengers and staff.
They were each fined £100,000.
The court heard members of the public had been exposed to a substantial risk of danger.
The 39 tonne train was out of control for 16 minutes and passed through stations while passengers on the platform looked on at 06:30 BST on 13 August 2010.
The two maintenance workers on board managed to jump off at Highgate station.
Passengers on the train in front were instructed by their driver to move through the carriages to the front of the tube as it passed through stations as the runaway gained on them.
Prosecutor Jonathan Ashley-Norman, for the Office of Rail Regulation, said there could have been a "terrible tragedy" had it not been for the "prompt and skilful actions" of London Underground staff in the control room.
He said they managed to switch lines which slowed the runaway train so it came to rest as it reached an incline near Warren Street station in central London.
The court was told a coupler which had been attached to the broken-down track maintenance wagon broke, allowing it to detach from the train which was pulling it.
The Old Bailey heard that all three companies had made major improvements since the incident.
Keith Morton, QC, for the Tube companies, said: "London Underground is one of the safest railways in the world - if not the safest."
LU director Mike Strzelecki said it has since put in place tighter approvals and controls for the design and use of all engineering trains.
"LU staff's swift actions meant that this incident was drawn to a safe conclusion," he added.
Ian Prosser, Office of Rail Regulation safety director, said that in this case, the train companies through "inadequate management and planning" had failed to ensure the safe recovery of an engineering train.
"This is clearly unacceptable, and led to a potentially catastrophic incident on the Northern Line where the train careered out of control for over four miles.
"It was only the professionalism of control room staff taking decisive action which prevented a collision between trains, and averted a much more serious outcome."