Network says it has concerns over 'TfL's handling and management of both the project and contractors'

Network rail has banned Transport for London’s contractors from working on the bridge at Liverpool Street station which collapsed on Wednesday.

Network Rail said the ban, which will affect firms including Carillion and Balfour Beatty, had been introduced because of “concerns over TfL’s handling and management of both the project and its contractors.”

The ban will remain in place until TfL has completed an investigation and can show what measures it will put in place to avoid a repetition of the incident, in which falling debris hit a train.

Network Rail's chief executive has written to Transport for London's Commissioner Peter Hendy to seek “urgent answers” about the severe disruption caused to tens of thousands of passengers.

Commenting on the incident, Network Rail's director of operations and customer service, Robin Gisby, said: "Passengers rightly want an explanation, as do I. Passengers deserve an apology for the disruption they suffered and I want assurances that such an incident can't and won't happen again."

TfL confirmed it had begun an investigation with Balfour Beatty and Carillion, and Network Rail and apologised to passengers for the disruption.

In a statement TfL said: "We have no plans to re-commence works on the bridge until we have fully reviewed this incident. Network Rail were fully consulted and agreed to the programme of works for the installation of the bridge."

Trains into Liverpool Street Station were cancelled Wednesday night and Thursday morning after debris from the newly built bridge fell onto train tracks.

Passengers deserve an apology for the disruption they suffered

Network Rail

The incident happened about 200 yards outside of the station as work was being carried out to construct a bridge for the East London Line extension.

At about 7.30pm Wednesday the 1800 tonne steel truss bridge was being moved into its final fixing position using jacks.

One of the jacks gave way causing the the bridge to drop about 200mm and debris to fall onto the main line tracks below.

A train hit the debris, forcing 300 passengers to walk along the tracks to reach the station. No injuries were reported.

TfL said its engineers worked overnight with the contractors and Network Rail to restore services to Liverpool Street.

A Balfour Beatty Carillion joint venture won the £363m contract to create the new East London Line extension in 2006. It is due to open in 2010.

Fairfield Mabey is the bridging contractor that was carrying out the work.