Rail companies fined for derailment

HSE Press Release: E080:04 - 2 July 2004

Two rail companies, Network Rail Infrastructure Limited (NRIL) and AMEC Rail Limited (ARL) were today fined a total of £70,000 at a sentencing hearing at Southwark Crown Court. The case followed an investigation by the Health and Safety Executive (HSE) into the derailment of a passenger train outside West Sutton station in Surrey in 2001. There were no reported injuries and services were reinstated the following day.

On the evening of 9 October 2001, the seventh coach of an eight coach Thameslink passenger train derailed both bogies shortly after leaving West Sutton station at about 18.30 hrs. The train was travelling within permitted line speed, which was 30 mph, and an examination of it did not reveal any faults that could have caused the derailment. At that time Railtrack (now NRIL) was the infrastructure controller and ARL was the infrastructure maintenance controller for the area. HSE's investigations revealed that the cause of the derailment was the condition of the track.

HSE inspector Steve Turner, who investigated the derailment, said: "This was a relatively low speed derailment which happily did not result in any injuries. The investigation revealed that the immediate cause of the derailment was 'gauge spread', that is when the track under the train widens and causes the train wheels to drop in between the rails. Gauge spread can occur over time and it is well known in the rail industry that, if it persists uncorrected, it will result in derailment. Both companies had a duty under the law to ensure that the track was inspected, maintained and repaired; all of which would have picked up this fault and prevented the derailment from happening. Network Rail's new arrangements for managing track maintenance should ensure that a similar incident is less likely to occur."

NRL and ARL each pleaded guilty at earlier hearings to breaching Section 3(1) of the Health and Safety at Work etc Act 1974. NRIL, of Euston Square, London was fined £30,000 and ordered to pay costs to HSE of £12,500. ARL of Stephenson House, Cherry Orchard Road, Croyden, Surrey was fined £40,000 and ordered to pay costs to HSE of £17,500.

Notes to editors

1. Section 3 (1) of the HSW Act states, "It shall be the duty of every employer to conduct his undertaking in such a way as to ensure, so far as is reasonably practicable, that persons not in his employment who may be affected thereby are not thereby exposed to risks to their health or safety."

2. The maximum penalty for a single offence under Section 3(1) of the HSWA in the Crown Court is an unlimited fine.

3. The derailment occurred as the Thameslink train was travelling through a sharp left curve just outside of West Sutton Station. The driver first became aware of a problem when he noticed that the 'line light' had disappeared on the control panel, which meant that the train had lost the traction current, supplying electricity to the train. Just before the train left the track it had been travelling at 29mph. The maximum permitted speed was 30mph due to the curvature of the line. After it became derailed, the train began to slow due to the gradient of the track and eventually came to a stop. Records suggest that the train had run without power for some 340 yards. The train was carrying approximately seventy passengers. No one was injured and minimal damage was caused. Investigations showed that the immediate cause of the accident was the condition of the track, not driver error or the condition of the train.

4. HMRI began an immediate investigation; enforcement action followed with the serving an Improvement Notice (IN) on AMEC. The IN required a number of steps to be taken by 31 January 2002, specifically 'to improve the arrangements to effectively plan, organise, control, monitor and review the maintenance of the permanent way.' The terms of the IN were complied with within the time specified.

5. The derailment occurred because of a phenomenon known as gauge spread. Railway track consists of two parallel rails that should be held at a prescribed distance apart by sleepers. Gauge spread refers to the distance between the rails increasing as the train passes over causing the train wheels to drop in between the rails. It is well known within the railway industry that gauge spread can cause derailments; indeed it was the single most common cause of derailments in 2001/2002. The track at West Sutton had been installed in 1979 by British Rail and comprised rail fastened to cast iron base plates, known as Pan 8 baseplates, by spring steel clips. These baseplates were in turn fastened to hardwood timber sleepers by steel spikes - lock spikes - which were driven down through a hole in the baseplate and into the timber.

6. Gauge spread occurred because of corrosion failure of the lock spikes. This was a known and documented failure mode prior to the derailment. HSE's investigation discovered that the problems at West Sutton had persisted for some time but had been wrongly diagnosed. Effective procedures to identify and remedy such faults ought to have been in place. Since the derailment both Railtrack and AMEC have taken a number of steps towards improving the systems for inspection, repair and maintenance of the track in that area. Railtrack also sent an alert to those engineers elsewhere who had responsibility for similarly constructed track.

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