Tube tunnel drama

Ten crowded commuter trains were damaged today after a blunder by maintenance workers left metal brackets sticking out of a tunnel wall.

The workers had installed the wrong sort of brackets, which stuck out further than the old ones. Three trains each had a passenger window smashed and others suffered damage to side panels.

The incident happened between Farringdon and Barbican stations during the height of the morning peak period. Tens of thousands of commuters suffered delays as large sections of the Circle, Metropolitan and Hammersmith & City lines were halted.

The brackets were installed by subcontractors for Metronet, the private sector consortium responsible for maintaining two-thirds of the Tube network. Metronet spokesman Paul Emberley said the contractors were from Balfour Kilpatrick, part of the giant Balfour Beatty group.

They were carrying out "essential cable works" between Farringdon and Barbican stations.

Three cable support brackets were installed "as part of a temporary works process". But they were larger and protruded further than the existing brackets.

"As a result some saloon cars of 10 trains have been superficially damaged and the outer skin of three saloon car windows was broken," Mr Emberley said. Metronet has already begun a formal investigation into the incident.

The RMT union demanded an immediate investigation and repeated their call for 24-hour track inspections.

The chaos came as Tube bosses threatened to tear up private infrastructure contracts unless performance improves.

This follows last month's massive disruption of the London transport network by one night of snow.

The private companies - handed 30-year contracts last year - are facing £1 million in fines because huge numbers of trains could not run the morning after the snowfall.

Today London transport commissioner Bob Kiley said the badweather failures were symptomatic of serious underlying difficulties with the public-private partnership (PPP) contracts.

He told a board meeting of Transport for London: "If we don't see improvements in the maintenance performance or renewal activity which is broadly under way, then we may be at a point where we will have to revisit these contracts in a pretty vigorous way.

"At the end of the second year all forgiveness is over.

"We have got to stand ready to do what we can to protect the interests of the public, and this board's interest. The moment of truth will come sometime during the second year."

Tim O'Toole, the Tube's managing director, said: "The performance of the Underground defies any defence through this period."

He revealed that "robust discussions" with the two infrastructure companies had taken place as a result of the fiasco. "We are determined this will not happen again," he said.

Mayor Ken Livingstone also threatened to cut the grants given to borough councils for transport projects unless they ensured bus routes were properly gritted.