So far in Automation Week we’ve concluded that automatic metros are likely to become the norm, that heavy-haul freight is a less suitable candidate, and that high-speed rail could in time run automatically with driver supervision. Today, we’re going to examine the issue with potentially the greatest benefits and unquestionably the largest technical challenges: automating a high-density mixed use railway.
The busiest railways in Europe and elsewhere carry a huge range of traffic. From 100km/h freight trains to 120km/h local services, 160km/h interurban trains and 200-225km/h inter-city services. Services will join and leave the core route regularly, and stopping patterns vary wildly between the different trains. Is it possible, then, to reap some of the benefits seen on automated metros to a full railway network?
Signalling and train control are fundamental to achieving this. The most modern systems understand the performance characteristics of the trains and their schedules – and with the ability to apply power as well as braking, there is no reason why conceptually supervised automatic operation couldn’t be applied across a whole network.
The technical challenges are gigantic, however. Aside from the logistical challenges of equipping the rolling stock and infrastructure with the necessary equipment, the software and computing capabilities in the control centres required will almost certainly need to be more powerful than existing systems. But, when the trains are running to time and there are no major operational issues, fundamentally it could work, allowing trains to run more efficiently and taking some of the workload of signallers in terms of dealing with routine disruption.
As ever, the question is – what happens when things go badly wrong? A failed train or lineside equipment, or in the worst case of all, an accident, have the potential to trip up even the most capable automatic system. Given the sheer potential for events outside the railway’s control to cause disruption, it’s inconceivable that trains could operate in the sort of unmanned operation becoming common on metros. At some level, both in train cabs and in signalling centres, human supervision and intervention is going to be necessary.
But that doesn’t mean that a system which knows where every train on the network is and how it is running won’t enhance the punctuality and performance of a mixed use railway. One of the daily challenges signallers face is in train regulation. Should they allow an on-time local service to run ahead of a late inter-city train? At key junctions at busy times, which trains should be held outside the station awaiting platforms, and which should be allowed a clear run? All of these decisions can have major consequences which ripple out far beyond the immediate location – delaying a service at one point might mean passengers miss connections elsewhere, and so on. Making the right decisions all the time is impossible.
This where our hypothetical ‘intelligent’ railway can help. As delays and disruptions happen, software could assess the potential ramifications across a whole network far more quickly than even the best signaller and recommend options for dealing with the situation. It would have to be the signaller’s decision, but it would be a decision based on the signalling system’s evaluation of potential actions. At a stroke, the signaller’s workload is reduced, providing him or her with fewer things to consider and making it more likely that the best decision for customers and the railway is made.
We can go beyond this: most new trains have onboard diagnostic and predictive maintenance systems which highlight potential faults before they become critical. The tracks themselves are better monitored than ever before, and passenger information and ticketing systems are now updated in real time. What if all of those currently discrete systems can be integrated with signalling and train control to provide a whole-railway management system?
The benefits could be vast: if the signalling system is aware that a train has an impending fault it could adjust the driving automatically to maximise the chances of on-time arrival; if an issue is developing with the infrastructure, trains could be slowed in one place and speeded elsewhere to keep the service running. And when trains are running unexpectedly empty en route, train operators could adjust ticket prices on the move for intermediate stations to give passengers the best value possible. The whole railway would have a total picture of events, a simulation of what’s likely to happen in the case of disruption, and the data to be able to make the very best decisions to keep trains moving in all but the most extreme circumstances.
It may be a long way off, but ERTMS, CBTC and PTC – not to mention rolling stock providers’ predictive maintenance systems – are all gradually providing the foundations needed for an integrated, intelligent railway which offers even greater safety, reliability and punctuality than at present. It won’t happen within the next decade, but at some point in the 2020s or early 2030s, the foundations being laid now will lead to a truly intelligent, integrated railway. We’re confident of that, but what do you think? Let us know your thoughts…