ADRIAN SWINDELLS explains how matching the right industrial PCs to the task in hand requires thought and forward planning
Until the 1980s, it was forbidden to use electronics for any safety critical system on the railway, as the behaviour of electronics was not well understood by engineers. However, the development of the microprocessor changed all that, and electronics systems were trusted to pass signalling information from the track to a train.
Anyone who has travelled by train will know how prevalent screens are across the rail industry. From booking or collecting a ticket to checking what platform a train will arrive on or even getting a coffee on board all involve a screen of one kind or another. Behind the scenes, industrial PCs are used extensively to control signalling and train functionality.
Any PC used in the rail sector, whether for customerfacing or staff use, must overcome a number of challenges. Screens for customer interaction in stations may not face as many challenges as an industrial PC situated in the tunnels of the London Underground, but robustness is still vital. Vandalism is a serious problem in the rail industry, with vandals causing up to £60,000 worth of damage in Edinburgh alone in 2016. Any screens used on the railways or in stations, therefore, need to be highly rugged and secure to protect against intentional damage.
Location, location, location
On the other side of the coin, rail engineers need to carefully consider the location of any PCs they intend to use to control their networks before choosing which model to invest in. For example, on the London Underground temperatures can hit extreme levels throughout the year, which is why we recently supplied Transport for London with Siemens Microbox PCs. Box PCs have a rugged enclosure so they are able to function effectively in ambient temperatures up to 55 degrees Celsius.
However, in environments where PCs may be exposed to high levels of dust or water, a panel mount computer that incorporates an LCD panel would be more suitable as the front panels of these computers are IP65 rated. Fully cased PCs provide the maximum protection as they are completely enclosed and so do not require additional protection around electronic components. This is why we provide industrial PCs with a seal of up to IP69K, the highest protection rating in the industry. These PCs are also particularly useful where space is tight, such as in small trackside control centres.
Return on investment
Rail systems have to be built to last, especially when you consider the significant investment being made. For example, in 2011, Network Rail announced that it would consolidate its 800 signal boxes, some dating back to the 1880s, into twelve Rail Operating Centres (ROCs) across the country. From start to finish, this project is going to take more than two decades and will cost around £1.1 billion. It is therefore essential that the products used in rail projects are not going to become obsolete quickly.
Many rail organisations use large, experienced companies to fulfil their orders, which is why procurement teams for the London Underground chose Siemens products upon expert advice from Distec. The products are guaranteed to be available for five years and replacements or spare machines are available for a further three years, ensuring longevity.
When choosing an industrial PC, engineers should also be mindful that some companies provide computers with pre-installed operating systems, whereas rail networks often use alternative operating systems. Engineers should therefore choose a brand that can accommodate their specific needs and avoid smaller manufacturers that preinstall an unnecessary operating system.
All of these needs, and more, are covered by the EN50155 standard, which applies when electronic equipment is installed on a train. The standard specifies that all of the equipment must be reliable and able to withstand harsh environmental conditions, such as extreme temperatures, high tolerance against shock and vibration. EN50155 states that equipment must be able to operate for approximately 250,000 hours without failure. This is especially applicable to electronic equipment onboard trains, as such equipment often is used on telematics, engine control or other vital roles to the safety of the train and its passengers.
Another important part of the EN50155 standard is the electromagnetic compatibility of equipment. In tight control cabins, space can be limited on control panels, so engineers often have to mount equipment close together. This means that systems must not generate interference that could cause other equipment to malfunction or fail. It is therefore vital that when rail companies choose an industrial PC, they consult with specialists to minimise interference.
Since 1980, the introduction of electronic systems on the railways has led to improvements in safety, reduced delays and cost savings. There are also many more changes to come, with the introduction of further ROC’s by Network Rail, so it is vital that rail companies choose the correct type of industrial PC needed to maintain effective network functioning.
Adrian Swindells is director at industrial computing specialist Distec Ltd