AS ANTICIPATED in RG 2.00 p81, crashworthiness looks set to be a significant issue emerging from the Ladbroke Grove collision 3 km from London Paddington, which killed 31 people on October 5 1999. In its third interim report on the accident, released on April 14, the Health & Safety Executive puts the combined speed of the trains at 233 km/h - by far the highest closing speed ever recorded in a head-on train collision.

The report confirms that the aluminium-bodied leading car of the Class 165 Thames Turbo was split open by the Class 43 HST power car, noting that the vehicle ’virtually disintegrated in the impact, with structural fractures occurring along weld lines’. As part of the investigation, a ’limited reconstruction’ of the leading car has been undertaken, together with a detailed survey of all the damaged coaches. This has been used to compile a record of damage and component failure, looking principally at the main structural members.

As part of the HSE’s work, WS Atkins Rail Ltd is studying the crash performance of aluminium and steel. Finite element models have been completed for a Class 165 car, a Class 43 cab, and a steel-bodied Class 321 EMU car. This was chosen for comparison as it has doors in similar locations to the 165, works similar duties and was built at a similar time.

Investigators are also looking at the comparative crashworthiness of aluminium and steel fuel tanks - fuel released from the aluminium tanks of both trains at Ladbroke Grove, probably ignited by the 25 kV overhead wires, or heat and sparks generated by the impact, was the source of the fire after the collision.