Report 22/2009: Collision with debris from bridge GE19 near London Liverpool Street
Collision with debris from bridge GE19 near London Liverpool Street, 28 May 2008.
At approximately 19:17 hrs on 28 May 2008, train 1K12, travelling from London Liverpool Street to Southend Victoria collided with concrete debris lying on the track beneath a newly constructed bridge generally known as bridge GE19, shortly after it had left Liverpool Street station. This debris had fallen from the bridge following the failure of supports at one end of the bridge deck. This failure caused a sudden jolt which shook the deck, dislodging the concrete planks. Damage to the train was minor and there were no injuries. However, concern over the stability of the bridge resulted in the signaller stopping all other trains in the vicinity. It was some hours before the safety of the structure could be assured, and services did not recommence until the following day.
The immediate cause of the accident was the concrete planks falling from the partly-completed deck of the bridge onto the track below. This was because of:
- the unexpected movement of the bridge deck which was positioned on a steep gradient and inadequately restrained
- an inadequately planned operation to restore the deck to its correct position. This involved modification to the temporary supports and caused them to become unstable
- the decision to omit a recommended connection between individual pre-cast concrete planks, which allowed the planks to fall from the deck when it was exposed to a large jolt, and fall onto the track.
Since the incident, the bridge has been repaired and completed.
As a consequence of this accident, the RAIB has made seven recommendations, targeted at Network Rail, Health and Safety Executive (Hse), London Underground Limited, Rail for London, the Heritage Rail Association, the Light Rail Engineering Group, Northern Ireland Railways and National Express East Anglia, the operator of the train. These recommendations cover the following areas:
- Safety Management Systems and procedures, to satisfactorily approve construction work on or over operational railways
- procedures so that information is available to operations staff where construction activities might affect the safety of the railway
- the expansion of the Network Rail’s National Emergency Plan in the light of this incident
- the wider promulgation of issues identified from this incident amongst the civil engineering community
- the enhancement of incident management training given to operations staff.
Response to recommendations:
- RAIB will periodically update the status of recommendations as reported to us by the relevant safety authority or public body
- RAIB may add comment, particularly if we have concerns regarding these responses.