Transport for London is carrying out an urgent investigation after two Bakerloo line trains hit a “bulge” in the tunnel’s steel lining under the River Thames yesterday.
Transport for London (TfL) is still investigating the cause of the bulge, which was first detected at 7am yesterday morning, and is not clear whether it is related to grouting work taking place in the tunnel over the past week.
The line was partially-suspended all day yesterday after two southbound trains hit the bulge between Embankment station north of the River Thames, and Waterloo on the south. It did not cause any train derailments, but did damage door indicator lights on the outside of some carriages before detection. The line reopened this morning.
The incident happened in the midst of a three day strike of maintenance workers on three other London Underground lines but the Bakerloo line was unaffected by the strike action.