The potential emergency was only averted because an automatic warning system held the train up at a signal before it reached the maintenance crew and the gap in the tracks.

The workmen had cut one of the railway sleepers at Thirsk, North Yorkshire, and were preparing to remove it when a call came through from a signalman, puzzled about why a Manchester Airport to Newcastle train was still waiting at the danger signal.

The train was stopped because the work had disrupted an electrical circuit. When the circuit is working it tells the train operators that there are no trains on that section of the line.

When the circuit is broken it makes it appear there is a train there and the danger sign goes up to prevent another one coming until the track is clear.

According to the investigation into the incident, on January 11, the construction crew were lucky to have severed the rail that made up the electrical circuit, so the train stopped without harm.

But a report by the Rail Accident Investigation Branch (RAIB) points out that there might have been a different outcome if the men had cut the other rail.

This was not in the warning loop and the train might have continued.

The report concluded: "The consequences of this incident were benign due to the fact that track circuit was interrupted as the rail was severed. This caused the track circuit to show occupied and the associated signal was held at danger."

However, the train could have approached the work site if it had already passed the signal when the rail was cut or the other rail had been severed, or if the line had not been fitted with the warning system, the report underlined.

It added: "If the train had approached the work site there would have been a significant risk of serious injuries to the track workers and a possibility that the train would have derailed."

The report is unable to clarify whether similar incidents have happened in the past – when maintenance has been carried out on the line without all the procedures being followed to ensure everyone knew about it.

"However, the data collected from the Network Rail National Control Log indicates that there are still a significant number of incidents in which misunderstandings, miscommunication and planning errors contribute to serious operating irregularities," the report states.

The responsibility for the day-to-day maintenance of the track lies with the depot at Darlington while Network Rail's offices in Newcastle and York are supposed to share information about where work is going on so services can be organised around the repair sites.

In this case there was no evidence that a form explaining the work had ever been sent from Newcastle to York – so the Manchester Airport train was still scheduled to call at Thirsk station as the last one of the night.

The maintenance crew involved believed they were in a safe area already isolated for work elsewhere, though in fact they were outside it on a track still open to traffic.

The RAIB made eight recommendations following its investigation, seven to Network Rail covering staff briefings, procedures and documentation and one to the Railway Safety and Standards Board covering forms used to draw up maintenance areas.