The new doors will be fitted to the company's high speed trains

The �700,000 modifications will mean passengers will be able to remove part of an internal door and relocate to another part of the train in the event of an emergency.

Work to the fleet of 317 HST carriages was due to begin later this month, said a company spokesman, and would mean replacing existing partitions with sliding vestibule doors which feature a removable central panel.

Seven people were killed and more than 150 were injured, some of them seriously in September 1997, when an eight-carriage Great Western-run train crashed into the side of a goods locomotive that had been crossing its path.

The Swindon-based company's engineering director, Graham Boot-Handford, said: "One issue highlighted by passengers has been the difficulty of escaping from a carriage in an emergency.

"These doors have been developed for that reason. If a door is stuck, passengers can quickly and easily release the panel and get out of the carriage."

Eddie Morland of AEA Technology, developers of the doors, said: "They are a real move forward in terms of rail safety and simple for passengers to use."