BRITAIN’s Rail Accident Investigation Branch (RAIB) issued a statement on June 24 giving initial details of the movements of two passenger trains just before they collided on June 19, resulting in the death of one driver and injuries, including some serious, to more than 160 people.

RAIB says the collision happened at 17.15 when a class 360 Siemens Desiro four-car commuter EMU travelling to London as train 1H46 ran into the back of a stationary London-bound inter-city service operated by a class 810 Hitachi Aurora bi-mode five-car unit running as train 1B67 near Bedford, around 80km north of the British capital. Both trains were operated by East Midlands Railway (EMR). RAIB estimates that train 1H46 was travelling at 79km/h when it collided with the rear of train 1B67.

The on-train data recorders (OTDR) have been recovered, according to RAIB, though some were located within damaged parts of the trains and could only be extracted during recovery operations. This includes the OTDR from the front of train 1H46.

CCTV recordings, signalling data and recordings of radio communications have also been obtained. Both trains have been surveyed for internal and external damage, including using laser scanning and an aerial survey. RAIB inspectors are also overseeing the testing of signalling equipment in the area. The trains have been removed from the railway and transported by road to secure storage.

Initial analysis

RAIB says that initial analysis of OTDR data and external CCTV cameras show that train 1B67 was brought to a stop unexpectedly at Signal WH152 due to malfunctioning of the train’s Automatic Warning System (AWS) equipment. As a result, the signalling system automatically changed the preceding signal, WH154, to show a red aspect. CCTV from train 1H46 confirms that this red aspect was displayed as the train approached and then passed the signal.

Until the OTDR from the front of train 1H46 is analysed, RAIB says “it is not possible to say what indication the driver received from the AWS equipment on the train or how the driver responded to this.” OTDR data from the rear of train 1H46 shows that a brake application was made around nine seconds before the collision when the train was travelling at an estimated 122km/h.

RAIB says its investigation will focus on many factors, including:

  • the actions of those involved and any factors that may have influenced them
  • the status and performance of the braking, AWS and other safety systems on train 1H46
  • the reason train 1B67 stopped
  • the status of signal WH154 and its AWS equipment, as well as its positioning, visibility, and conspicuity
  • the crashworthiness performance of both trains during the collision
  • the emergency response to the accident
  • the processes used to assess the risk of overrun at this location, and
  • the effectiveness of any control measures intended to address this, as well as any relevant underlying factors, including actions taken in response to previous relevant safety recommendations.

 “The report makes clear there is still much to establish, and the full investigation will provide the answers and recommendations everyone affected deserves,” says transport secretary, Heidi Alexander, in a statement responding to the publication of RAIB’s initial findings, in which she also requested that “RAIB be given the space to complete their work thoroughly and speculation is avoided so we can establish the full picture and ensure the right steps are taken in response.”