Paddington train disaster: Blaze highlights a new rail danger

THE DISTINGUISHING, and terrifying, factor of yesterday's rail tragedy was the outbreak of fire after the two trains collided, causing many of the worst injuries.

THE DISTINGUISHING, and terrifying, factor of yesterday's rail tragedy was the outbreak of fire after the two trains collided, causing many of the worst injuries.

Experts said it was highly unusual for diesel to ignite, even in a crash, and that this indicated the amount of heat that must have been generated by the impact. One theory was that the fuel tanks of the First Great Western 125 high- speed train had been ruptured, and their contents spilt on to hot engine parts, leading to the fire.

This exposes another area that designers will have to address, in addition to the progress already made in making trains safer. For both trains involved in the fatal collision had carriages regarded as among the safest.

The high-speed train is based on a Mark 3 coach design, which was a pioneer when introduced more than 20 years ago and is still seen as setting a bench mark. The units of the other train involved in the crash, the Thames Trains Networker Turbo, are the most modern, introduced seven years ago and built to the highest safety specifications. Both feature "monocoque construction", meaning the bodywork containing the passenger compartments is built as a single unit with the chassis carrying the wheels, to dispense with a dual construction of heavy chassis and lighter carriage.

The shortcomings of the older design were tragically demonstrated at the Clapham rail disaster in south London in 1988, in which 35 people died. When the two "slam door" commuter trains collided, a number of the carriages disintegrated, with the bodywork separating from the chassis, killing or maiming many inside.

The only consolation for modern designers must be that yesterday's death and injury toll could have been a lot worse. "If these trains had been of the old design, then we could have been talking about hundreds being killed," said Howard Johnston, technical consultant to Rail magazine.

But nothing so far produced, it seems, can prevent further tragedy when two trains have a near head-on collision.