Railway Maintenance: the New Frontier of Wireless Monitoring
Railways are in need of constant maintenance in order to ensure the safety of both passengers and railway workers. On top of this, the downtime of railway lines costs railway companies severely in economic terms, not only in the form of remedial action but also due to customer dissatisfaction and compensation. At the moment, railway monitoring for predictive maintenance is pretty basic: for most railway networks, a special train with sensors on its wheels runs through the whole rail network once within a fixed period of time, usually 6-12 months. This train measures several key parameters across the entire railway system. In particular, it tracks changes in the height difference and width between the two lines because if these distances change, the risk of train derailment can be massively increased. The ‘monitoring train’ thus identifies where any corrections in the lines may be needed. However, this measurement is only taken sporadically; in the remaining months, nobody knows what is happening.
Railway operators thus need a new way of monitoring that will allow them to constantly know how tracks are faring. Wireless monitoring is one solution that can give operators access to real-time data on the tracks that they oversee.
We will examine some of the benefits of real-time wireless monitoring systems for the railway industry:
1. Optimize maintenance cycle
Wireless monitoring systems relay real-time information to railway operations centers, meaning that operators have access to a continuous stream of information about the status of their tracks, allowing them to optimize the maintenance cycle. As opposed to traditional methods of monitoring, such as the ‘monitoring train’ mentioned above, which only produce outdated information every few months, wireless, real-time monitoring allows operators to see the real situation on the ground at any given moment. This means that they can spot potential anomalies in the railway tracks and carry out maintenance not just reactively, but actually prior to incidents happening. If one area of the track appears to be moving outside the parameters of what is ‘normal’, then railway operators can deploy railway maintenance teams to check the area and implement necessary actions before anything happens, such as a train derailing.
2. Introduce prediction
If combined with machine-learning tools, wireless monitoring solutions can also enhance their ability to predict potential incidents over time, building more accurate models as further datasets are inputted. Accumulating data about the status of the tracks over a long period of time gives operators the opportunity to build predictive models. It also provides them with access to accurate, long-term information about how the tracks are likely to behave under certain circumstances, such as during extreme weather incidents like heat-waves or frosts.
Long-term measuring of how the tracks and surrounding ground behave is necessary for strategic modeling and planning: notably, it allows predictive maintenance to be planned ahead of time, even if no anomalies are flagged up.
3. Addresses railway-specific needs
Railways have specific monitoring needs; wireless monitoring systems can address these in a number of ways if they offer the right railway-specific meters and software.
- Firstly, tracks have to be regularly monitored using a tiltmeter because of the need to be able to measure diagonally. Since you cannot equip the whole network with these meters and sensors, the wireless monitoring system vendor needs to help the railway company identify strategic points along the tracks where measurements are the most crucial (perhaps points that are vulnerable to fluctuations) and will most accurately reflect the status of the rest of the tracks. Attaching a tiltmeter to a part of infrastructure where you know there is a higher chance of tilt will bring better results in terms of being able to prevent incidents. This can then be used to monitor existing static infrastructure like tunnels and bridges.
- Moreover, railways need a low-maintenance, remote system, as certain parts of the tracks can be difficult, risky or disruptive to access, and maintenance or monitoring could mean downtime of the tracks. Durability is also key. Railway tracks are harsh environments: they face all weathers and are exposed to very heavy, fast-moving metal machinery (i.e. trains). Monitoring hardware, such as sensors and the data nodes that are used to digitalize them, need to be as durable as possible. Many wireless monitoring systems are specifically designed for this, so railway operators should look for the vendor that can guarantee durability.
A photo of a train that derailed after a landslip between Arisaig and Glenfinnan, Lochaber, January 2018 (Picture: PA)
4. Monitoring of surrounding area
Wireless monitoring solutions not only allow operators to monitor their railway tracks but also the surrounding area. This is essential: often incidents, such as derailments, are caused not by faults in the track but by movements in the surrounding ground. A train in Scotland, for example, was derailed in January 2018 after dramatic weather caused a major landslide. Measuring how the ground behaves around the tracks is especially key if there is a construction site nearby: operators need to measure water pressure and ground systems, for example. Railway operators thus need a much larger breadth of knowledge about the whole area surrounding the tracks in order to gain a clearer picture of the situation on the ground. Constant data-feeds from sensors – positioned not only on core infrastructure but also in the surrounding area within boreholes, buildings or even in the ground – allows for context-modeling that can ensure accurate strategic planning and decisions.
The safety of both passengers and workers on railway lines is at the core of railway operators’ concerns. Real-time, predictive maintenance, enabled through wireless monitoring, allows operators to predictively maintain their tracks. This enables maintenance both in the immediate moment (flagging up problems as they arise) and in the long-term (building contextual and long-term strategic models to ensure the most accurate kind of maintenance deployment).
Predictive railway maintenance, based on IoT technology, massively reduces the risk of an incident happening since operators are able to both implement preventative maintenance actions and strategically plan for maintenance through accumulated data-sets.
This results in huge savings in the long-term: downtime of railway lines due to incidents costs railway companies thousands of dollars per minute. Moreover, remedial action after an incident is, in the long-term, significantly more expensive than smaller, predictive adjustments carried out regularly over time.
6. Long-distance, remote monitoring
Railway tracks are not easy to manually monitor and maintain. As there are many environments that cannot be manually monitored without having to put workers at risk or put the railway line out of use, long-distance, remote monitoring is a must-have for railway operators.
Another reason that IoT wireless monitoring is key for the railway industry is the need to monitor switch points.
Switch points, often located at random points along railway tracks in the middle of the countryside, are particularly vulnerable to being damaged by people who wish to vandalize railway equipment. Vandals can carry out significant damage to a switch point and put a railway line, or several lines, out of service for many hours, causing significant delays and costs to the railway provider. Using cameras and sensors to monitor switch points in real-time allows operators to see who may be interfering with a switch point, where it is happening and when. This also acts as a deterrent to vandals, who know they are more likely to be caught with sensors and cameras in place.
7. Integration with legacy systems
As different railway companies use diverse IT systems, and constantly interact with a range of public and private-sector stakeholders who each have their own systems too, any monitoring system needs to be able to be integrated with these existing systems. Many wireless monitoring systems can be integrated with any IT system, and can work with a range of sensors and data nodes, but not all offer this. Choosing a system that can easily be integrated with legacy systems and equipment, and a provider who can offer advice on how best to do this, is particularly essential for the railway industry – in which a great deal is on the line when it comes to instrumentation and monitoring.