A team of rail engineers has devised cheap and simple ways of reducing the deadly impact of terror attacks on trains and metros.
After studying the devastation caused by a bomb on a normal carriage, they have come up with potentially life-saving designs which could be introduced in the future.
Conor O'Neill from Newcastle University's NewRail research centre has developed a range of blast-resistant designs, looking particularly at reducing debris and containing any explosive shock wave.
His team studied the effects of the Madrid bombings in 2004 which killed 191 people, and the 7/7 attack in London a year later in which 52 passengers died. They also filmed an explosion on a decommissioned carriage, and analysed what happened in less than a second after a bomb went off.
In a train blast, the windows are blown out and shards of glass shower anyone standing on a station platform. But this could be prevented with a cheap plastic coating on the glass. They also looked at reducing flying debris by tethering down panels and, in a prototype, looked at using lighter, energy-absorbing materials in some places. As well as injuring passengers, debris hinders the emergency services' response by slowing their progress to casualties.
Mr O'Neill, based in the university's School of Mechanical and Systems Engineering, said: "The Madrid bombings in 2004 and the 7/7 attack in London the year after highlighted how vulnerable our trains are to attack - particularly busy metro and commuter trains. At the same time we have to be realistic - completely replacing existing vehicles just isn't an option.
"Instead, we have developed and incorporated new technology and materials into existing carriages to improve performance. And what we've shown is that companies could make some relatively cost-effective and simple modifications that would significantly improve the outcome of an attack."
The team closely studied footage of the staged blast, shot on high-speed cameras, to understand how the shock wave travelled through the carriage, and how the furnishings reacted. They then built a prototype designed with blast-resistance in mind.
"Preventing flying objects is the key," said Mr O'Neill. "Tethering ceiling panels reduced the risk of fatalities and injury from flying shrapnel and meant the gangways were kept relatively clear of debris, allowing emergency staff quick access to the injured. The window coating we developed was also incredibly effective. Without it the windows are blown outwards - putting anyone outside, such as those standing on a platform, at risk from flying glass."
He added: "A bomb on a train is always going to be devastating but what we are trying to do is find a way in which the vehicle itself can help to mitigate the impact of an attack. These are all low-cost, simple solutions that can be put on existing trains which could not only save lives but also reduce the attractiveness of our railways for potential terrorist attacks."