Improved carriage design could reduce bomb-related injuries

Engineers at Newcastle University are hoping to reduce the risk of injury from terrorist attacks on trains by improving carriage design.

The researchers have developed a series of measures that can be retrofitted to train or metro carriages in order to reduce injuries caused by bomb explosions, particularly those related to shrapnel.

The work was carried out as part of a three-year EU-funded project called SecureMetro, led by Newcastle’s NewRail research centre, as the precursor to developing new standards for carriage design that could be easily implemented.

‘The European Commission raised a security call based on the terrorist attacks in Madrid and London and it was felt more research was needed in this area,’ project leader Conor O’Neill told The Engineer.

‘We had a look at how vehicles can respond and what can be done from a design perspective to [reduce] the number of injuries and fatalities.’

One of the key improvements was the development of a tethering system to prevent heavy items such as speakers, emergency handles and even ceiling panels from flying around the carriage should their joints become detached in a blast.

As well as preventing them from hitting people or creating shrapnel, this should also prevent them from becoming debris and blocking a passenger’s escape route or preventing rescuers from entering the carriage.

‘We’ve been looking at a number of things [to create tethers] but even a simple method such as a thin wire cord is very effective, or even just building in a bit of flexibility around the joint areas allow the panels to move but they’re not so rigid that they end up being pulled out,’ said O’Neill.

Other changes include the use of anti-graffiti film on the windows to prevent them from shattering and lighter-weight and more energy-absorbent materials to reduce the impact of a blast.

The researchers found that tethering the ceiling panels prevented them from falling into the carriage

The researchers carried out a full-scale test explosion in order to assess how the blast impact travelled through the vehicle and its effects on the structure and interior, filming and playing the explosion back in slow motion to analyse its progress.

Other members of the research consortium in Spain conducted tests of individual components to assess a blast’s impact on different materials, joints and subassemblies.

The Newcastle team then used the results to build (and then destroy) a full-scale prototype carriage featuring the new adaptations, the results of which will now be used to make design recommendations to European standards bodies.

‘These aren’t big, heavy solutions and they’re not costly solutions either,’ said O’Neill. ‘We were very much of the mindset that these had to be retrofit solutions but they also had to be cost effective in order to ensure that later down the line they get implemented in vehicle design.’