On track with x-rays

08 Sep 09

By Nick Fox

With the terrorism threat comes the need for increased security at mass transit locations, such as train and bus stations and ports. Nick Fox, of 3DX-Ray asks: How can x-ray baggage screening be successfully implemented in mass transit hubs?

In the wake of the 07/07 bombings on the London Underground and bus network, the government announced its intention to scan the bags of rail passengers in large stations, in a bid to help tackle terrorism within the transport network.

Improved security was promised at 250 of the country's busiest railway stations, as well as ports and over a hundred other sensitive locations. Unfortunately, there is not a straightforward way to implement baggage screening as a security measure in these mass transit locations.

It is not realistic to expect buildings such as railway stations to be able to deploy and operate airport style security. Train stations are open and there is no equivalent of 'air side' like in airports.

As a result there is no natural barrier at which to perform security checks. Moreover, the volume of passengers moving through stations is huge. For example, in 2007 the London Underground exceeded one billion passengers per annum for the first time and 70 million passengers pass through Kings Cross alone every year.

Quick moving passengers

These passengers move quickly – the average intercity train has 700 passengers boarding in about 15 minutes. Unlike airports, rail passengers do not expect to have to turn up at a station hours in advance in order to catch a train.

The key issue is that there cannot be 100 per cent inspection of travellers and baggage in mass transit locations. Instead, random inspection needs to be implemented, but implemented effectively. In some cases the very presence of x-ray scanning equipment and security operators can act as a deterrent, but this is not true in all cases. So the difficulty becomes raising the deterrent level and increasing the security without impeding the everyday movements of the general public.

The police can be deployed in these transport hubs, using their stop and search powers. To support them, temporary mobile x-ray scanning stations can be set up.

However, even a temporary x-ray scanning installation can very quickly become 'part of the furniture' in mass transit locations if it is only used in one location or on a strict rota. At this stage the deterrent can go largely unnoticed by people using the building regularly.

For those individuals posing a threat, scanning equipment deployed with a fixed pattern will not be a deterrent as they will be able to work around the system in place. Consequently true portability is crucial.

Scanner on the move

The scanning equipment can then be manoeuvred between different areas of the site in question, acting as a deterrent within every portion of the building, sending out the message that 'no-where is exempt from detection'.

Portability, therefore, is the key requirement for x-ray scanning solutions in mass transit locations. However, a practical x-ray scanner for use in environments such as railway stations needs to fulfil several requirements. 3DX-Ray, in developing products for these specialised scenarios, has identified three elements that are crucial.

Obviously the first priority is the power source. There are very few or no power outlets in public areas, and being tied to these outlets would automatically restrict the portability of the scanner. The solution is a battery-powered product that can operate for the duration of an entire shift, between 4 and 6 hours.

The next priority is to ensure that, without needing a power source on site, that the scanner is easy to use and deploy. As a result the scanner needs to be compact and robust so that it can be easily moved to any part of the building. Moreover the ease of use extends to performing the scans themselves.

Analysis must be easy

Only the police can perform stop and search, so the scanner will not be accompanied by extensively trained and experienced x-ray screening operatives as are present at an airport. The scanner must, therefore, be quick and simple to use and the scans easy to analyse.

The last priority is image quality. Despite the need for portability, a scanner deployed in mass transit locations must still deliver high quality images with all the functions and features of airport style baggage machines.

This final point is important. The context, location and deployment may differ wildly, but ultimately x-ray screening at mass transit locations should not deliver anything less than the quality that can be expected in airports.

To make random screening in mass transit locations a real deterrent against terrorism, the system has to be flexible, depending on the needs of the location. However, a fully implemented national network of portable, flexible x-ray screening systems in operation at all major transport hubs would present a major deterrent and challenge to individuals wishing to cause harm.

Credits :

Nick Fox is chief technology officer at 3DX-Ray