The Rail Accident Investigation Branch has provided an update into the collision between two passenger trains last week in Bedfordshire.

At around 17:15, 1H46, the 16:40 East Midlands Railway Corby to London St Pancras service, collided with 1B67, the 15:50 Nottingham to London St Pancras service.

Sadly, the driver of 1H46 died as a result of the accident, with 162 people being injured, and at the time of writing, 8 people remain in a critical condition.

The On Train Data Recorders, which are similar to a plane’s black boxes, have now been recovered, though some of the recorders were located within damaged parts of the train and could only be recovered once recovery had started.

CCTV, Signalling and radio communications have also been obtained.

The trains are being recovered to a secure site so that the RAIB can complete its investigation work.

The collision took place on the Up Fast line between Bedford and Flitwick station. The collision involved a Class 360 unit and a Class 810 train.

The Class 810, which was forming 1B67, was standing at signal WH152, which had come to an unexpected stop due to a fault with its AWS equipment, which caused the brakes to apply.

Railway systems have shown that the track circuit for the section of track was showing that the section in which 1B67 was standing was occupied, which means that the signalling system would have changed the signal behind to be at danger (red).

WH154 is a four-aspect signal and means it displays the signal automatically. It is fitted with AWS equipment, which provides audible and visual warnings to train drivers.

When a signal is at danger, it sounds a horn to alert the driver of the speed change or signal. The driver must acknowledge this by pressing a button in the cab, and a visual reminder is lit up. If the warning is not cancelled, the emergency brakes are applied.

The RAIB says that 1H46 left Bedford at 17:10 on the up slow, and CCTV shows that the train passed through a yellow, which means that the driver can continue but be prepared to stop.

1H46 then headed to Bedford South Junction, where it crossed over onto the Up Fast Line; the signal protecting the junction also displayed a yellow aspect as it passed through.

The train then approached signal WH154, and CCTV footage from the train shows that this was at danger (red) before the train then passed it.

Data from the OTDR is still being analysed, so it is not yet possible to say whether the driver received warnings from the AWS equipment, and how they responded.

The rear unit of 1H46 has had its OTDR recovered and downloaded. This doesn’t show AWS activity as it was the rear unit. However, it does show speed and braking.

Preliminary analysis of the data shows that there was a brake activation around 9 seconds before the collision.

The train was travelling at 76 mph, and the train was doing around 49mph at the point of impact.

The RAIB’s full investigation will look into

• 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 
• any relevant underlying factors, including any actions taken in response to previous relevant safety recommendations.

You can read the full announcement from the RAIB on their website.