Train drivers could benefit from airbags to protect them in the event of a collision, according to research being carried out for the Rail Safety and Standards Board.
AEA Technology is undertaking an investigation into the design of cabs on behalf of the RSSB, and has been exploring various methods of improving driver safety.
As part of the research the team considered the use of seat belts, but ruled them out because they could cause severe neck injuries to drivers, and would prevent them evacuating the cab once they had applied the brakes, said RSSB’s vehicle specialist Ray Ford.
‘We came to the conclusion that a seat belt can be far too severe, and can create fatal injuries. The drivers have also said on a number of instances that they would much rather be able to jump out of the seat and run through the door at the back into another compartment, where at least they are away from the immediate crumple zone.’
Airbags, adapted to fit cabs, could provide protection without restricting drivers’ movements, he said. ‘We’ve done some preliminary work on them to see whether they do make a significant improvement, and they certainly make accidents more survivable.’
More work will have to be done to determine how best to adapt airbags to the many different driver cab designs, and whether they will be suitable for retrofitting on to existing trains, he added. ‘New- build is one thing, because you are designing the cab with airbags in mind. But it might not be possible to fit them in cabs that are already out there, so it may be more one for the future.’
To protect drivers from broken legs, knee bolsters made of a protective honeycomb material could also be beneficial, he said.
The researchers have carried out tests of both airbags and knee bolsters, and constructed a full-scale cab mock-up to validate their computer models.
A rail crash dummy, developed for another RSSB project investigating seat and table designs in passenger carriages, may be used for further tests in the mock-up cab. The device, believed to be the world’s first rail crash dummy, has fully instrumented fluid bags in its abdomen to demonstrate the affect of an impact with a table or driver’s desk on the vital organs.
The research project is also investigating steps to improve energy absorption, either by introducing longer crumple zones to the front of trains on current or future vehicles, or creating crumple zones behind the cab, so that the entire cab moves backwards on impact.
The project is due to report early next year, according to Jim Lupton, head of engineering research at RSSB. ‘We’ve already discussed with industry the progress of the project. Once this is complete we will discuss with industry how to take the results forward.’