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Portable x-ray systems at mass transit locations

While fixed point baggage scanners at airports are a very common sight, increasingly security services are looking to bring the benefits of x-ray inspection to other, more challenging locations, such as major train stations, by employing portable screening technologies. Nick Fox, CTO at 3DX-RAY, writes of the challenges technology vendors face in meeting this new demand and how technology can help deliver an effective security presence at these locations without impeding the everyday movements of the public.

“Railway stations, particularly the large city hubs, are some of the most challenging buildings for security operations. It is very difficult to implement airport style security in railway stations. Not only are the volumes of people traffic extremely high (70 million people pass through London’s Kings Cross alone every year), but also train stations are open buildings, with no equivalent of ‘air side’ as there would be in an airport. As a result there are no ‘natural’ barriers at which to perform security checks. Moreover, rail passengers do not expect to have to turn up at a station hours in advance in order to catch a train – the average intercity train has 700 passengers boarding in about 15 minutes. So installing a security barrier to perform checks would be both intrusive and unpopular.

Of course, that is not to say that security checks cannot be implemented at major railway stations, and it remains true that in times of terrorist threats and security alerts that railway stations must be subject to some form of security checks. However, there are significant challenges. The difficulty arises from the need to raise the security or deterrent level, at certain locations and times, without impeding the everyday movements of the general public around the station – 100% inspection of passengers and baggage is simply not realistic in railway stations or equivalent transport hubs. While Police can perform security checks using the stop and search powers granted under section 44 of the Terrorism Act, we have been developing technology to supplement the straightforward stop and search powers to enhance the measures security agencies can deploy in these scenarios. We wanted to find a way to introduce some elements of ‘airport style’ baggage screening to train stations.”

“As the threat of terrorism has become a fact of life, so too has the need for increased security at locations which deal with high volumes of people traffic – including locations such as major train stations. In order to meet the increased demand, we are increasingly seeing that portable x-ray screening devices have an important role to play in our operations,” commented Inspector Sean McGachie of the British Transport Police (BTP). The BTP is the national police force for the railways providing a policing service to rail operators, their staff and passengers throughout England, Scotland and Wales. Every day, it polices the journeys of over six million passengers. “X-ray technology has been part of frontline policing for a long time. However, the new generation of portable equipment we are deploying now helps us immeasurably with all of our key actions – whether that is Explosive Ordnance Disposal (EOD), evaluation of suspicious packages, customs searches, through wall scanning, vehicle scanning or suspect bag inspection. As the technology continues to develop so we are able to respond more quickly, more effectively and with greater accuracy – improving security and minimising disruption to the general public.”

Technical requirements
“Of course the first priority is to create a solution that is genuinely portable,” continues Nick Fox. “Even a temporary x-ray scanning installation can quickly become ‘part of the furniture’ if it is only used in one location or on a strict rota. It is important to be able to move any equipment around the different areas of the building in question – sending out the message that ‘nowhere is exempt from detection’. However, to enable that then clearly the power source is the next issue to tackle. Environments like railway stations rarely, if ever, have power outlets in public areas. As a result it is critical that a mobile scanner is battery powered and can last for an entire shift of between four and six hours.

Beyond these physical requirements there are also some important operational concerns to be dealt with as well. First and foremost amongst these is that regardless of where a portable solution can be deployed, it is unlikely that it will be accompanied by extensively trained and experienced x-ray screening operatives as there would be in an airport situation. The scanner needs to be simple to use to generate the scans, and moreover easy for security operatives to analyse the images produced. A third element is that these scans need to be fast – passengers in train stations are moving through the building quickly and in large numbers and are not expecting lengthy security hold ups. Therefore, in order for a mobile device to be successful it needs to perform its task quickly to minimise the intrusion into the everyday comings and goings of the general public.

Lastly, despite the above requirements, the device has to be a high quality x-ray scanner capable of producing high resolution scans to enable the detection of a wide range of possible threats – whether that is explosives, an improvised explosive device (IED), components of an IED or other weapons and threatening items. Portable or not, any device should not deliver anything less than the quality that can be expected at airports.

In order to meet these requirements we have based a solution on our Flatscan TPXi system. The FlatScan TPXi is a lightweight, portable, robust x-ray scanning system, originally designed to provide x-ray screening for EODs, suspect packages and unattended baggage. It has the largest active scanning area on the market and a very slim profile (only 5cm deep). Starting from that base we were able to develop the FlatScan POD.

The POD incorporates a lead lined portable screening cabinet, with the FlatScan-TPXi unit slotted in to place, where the scans take place in a safe environment. This is wheel mounted to enable operatives to manoeuvre the POD around a variety of buildings. The scans are fed directly to notebook computer for real time image processing. With the large panel provided by the FlatScan-TPXi system we were able to deliver very high resolution images. Moreover we were also able to incorporate key analysis features in a simple control panel including various colour modes, depth penetration analysis, data averaging, noise reduction, image processing and automatic calibration. These help those operating the system to quickly enhance the images in a variety of ways to quickly establish the absence/presence of a threat without the need for extensive training.

Finally we also made the whole POD battery operated to enable the device to be operated in locations without the requirement for mains power. Of course, the additional benefit of developing system in this way is that operatives can easily remove the FlatScan-TPXi unit to use as a standalone device.

Real world experience
The key to delivering equipment that is really “fit-for-purpose” and meets the high demands of real-world security scenarios in performance, usability and reliability is through actual experience in dealing with customers on the front line and also paying close attention to their requirements and the specific challenges that each agency involved has to cope with. It is this experience that we brought to the development of the POD system in order to deliver a brand new tool for security organisations to tackle security concerns in challenging environments. Nonetheless work continues to find more ways to aid security agencies, especially as the pressure increases on those agencies to reduce the time taken to assess threats, improve accuracy and reduce the overall disruption caused by security threats – better technology, and the right device, can deliver quicker, more accurate analysis, enabling better decisions to be taken on the frontline.”