Railway operators are increasingly achieving greater safety and efficiency by using digital technologies and computer‑based management, control, and communication systems. The technical advances in modern transportation that the Industrial Internet of Things (IIoT) enables are driving the development of further international standards in the railway sector.

Confusing Signals

The rail industry is experiencing mixed fortunes globally. Mainline passenger traffic has grown rapidly in Asia and South and Central America, but fallen in the Former Soviet Union, Eastern Europe, Africa and the Middle East, according to a report by German transportation consultants SCI Verkehr in 2017.

Railway operators are adopting digital technologies rapidly as they fight to attract passengers from low‑cost airlines and private cars and compete with the increasingly automated road freight sector.

Train at Cologne, Germany, main station. Credit: PixabayOperators are taking to smart digital platforms to improve passenger communications and sales. Old infrastructure is being replaced by Train Control and Management Systems (TCMS) empowered by the IIoT and “big data” analytics. Sensors installed in trains and along tracks enable monitoring, data collection and analysis to take place in real‑time as well as supporting remote diagnostics and predictive maintenance. The information collected should allow equipment, tracks and stations to operate more efficiently as well as improving safety and reducing costs.

Rail freight faces a downward trend due to the decline of heavy freight such as coal and steel and reduced growth in international trade. Rail freight operators are pursuing maximum efficiency and productivity by expanding their take‑up of the sophisticated Internet of Things (IoT) technology and IT systems already commonplace in the road freight industry.

Operators of passenger and freight services on rail networks worldwide seek to promote the highest levels of safety and reliability. The development of a growing range of international standards in the railway sector is driven by technical developments in modern transportation and a movement towards computer‑based management, control and communication systems.

Focus on Safety

Many IEC TCs (Technical Committees) and SCs (Subcommittees) collaborate on drawing up International Standards that cover the systems and components used in railway networks, metropolitan transport networks (including metros, tramways, trolleybuses and fully automated transport systems) and magnetically levitated transport systems.

IEC TC 9: Electrical equipment and systems for railways, prepares International Standards for the railway sector, which includes rolling stock, fixed installations, management systems (including communication, signalling and processing systems) for railway operation, their interfaces and their ecological environment. These Standards deal with the electromechanical and electronic aspects of power components as well as with electronic hardware and software components.

The safety aspects of TC9 encompass passenger safety, including alarm systems and communication between the operator and passengers; electrical safety; protection against fire; safety hazards in long tunnels; event recorders such as “black boxes” and automatic system surveillance and IT security for railways.

TC 9 is also involved in standardization projects to promote energy management for increasing energy efficiency in trains and associated infrastructure, particularly in the areas of energy saving. These include the use of TCMS to help optimize driving behaviour and manage energy; on‑board energy measurement systems to support energy calculation and the saving and recovery of braking energy – for example in the shape of reversible electrical sub‑stations, hybrid traction and on‑board or stationary energy storage.

IEC TC 56: Dependability, deals with the reliability of electronic components and equipment in rolling stock, and TC 100: Audio, video and multimedia systems and equipment, prepares standards for on‑board multimedia applications.

Other IEC TCs and SCs that cover the vast range of components and systems used in railway operations include TC 20: Electric cables; TC 22: Power electronic systems and equipment; TC 32: Fuses; SC 48B: Connectors; TC 79: Alarm and electronic security systems; and TC 106: Methods for the assessment of electric, magnetic and electromagnetic fields associated with human exposure.

The IEC cooperates with other international organizations to promote standardization and avoid duplication. A cooperation agreement between the IEC and ISO/TC 269: Railway applications, ensures coordination in the development of international standards related to railway applications between electrical and nonelectrical activities.

The IEC and the International Union of Railways, the worldwide railway organisation, (UIC) liaise on standards to increase the safety, efficiency and cost‑effectiveness of rail systems. The coordination between the IEC and the International Association of Public Transport (UITP) focuses on the development of international standards for urban transport.

IOT and "Big Data"

The railway environment generates a vast amount of “big data” from many interconnected stakeholders which can be used to improve passenger safety and the efficiency of station and freight operations.

As an article in the July 2017 Global Railway Review notes, “the complete big data architecture includes cyber-physical systems, the IoT and Cloud computing, all of which work together to create ‘smart railways.’”

On‑board control and monitoring systems turn trains into interconnected communication hubs, transmitting data among themselves and to network control centres, from which they also receive instructions.

Safety is a primary element of IoT applications in train management. For example, on‑board train location and detection systems enable trains to be “aware” of the positions of other trains, reducing the risk of collisions while allowing trains to operate safely in close proximity to one another. Speed monitoring and control are other important safety applications.

The multinational company Siemens, which runs various smart train programmes in Europe and the US, says the billions of data points from sensors and software platforms can be harnessed to “reduce unplanned downtime, improve operational efficiency, enable improved business planning and performance and generate energy and cost savings.” More effective and predictive maintenance is another major benefit.

Data sources include not only sensors on trains and trackside infrastructure but also station ticket gates and kiosks, video surveillance, car parks and monitors in buildings and freight yards.

Closely Observed Trains

Sensors used in signalling, control and protection applications play a major part in enhancing the safety and reliability of railway operations.

Thousands of sensors embedded in systems and components on trains can detect a broad range of individual parameters such as location, vibration, speed, direction, pressure and temperature. These sensors provide information about the wheel‑rail interface as well as on‑board equipment.

For example, accelerometers based on MEMS (micro electromechanical systems) that monitor vibrations in train axles can detect potentially dangerous anomalies in the rails. Vibration data can also indicate signs of wear on bearings and wheels, and signals can be sent automatically via the IoT to notify train operators that components need replacing.

Sensors in doors can indicate their level of wear and tear and whether they are able to close safely and within an acceptable timeframe. Trackside sensors contribute other vital data on the temperature and safety of tracks, embankment stability and the condition of bridges and other infrastructure.

SNCF, France’s largest railway operator, is using thousands of sensors to equip a network covering 30,000 km of track, 15,000 trains and 3,000 stations. SNCF’s latest Paris commuter trains are fitted with 2,000 sensors, which forward 70,000 data points per month. This enables engineers to monitor up to 200 trains at once remotely for potential problems including door or air conditioning failures, while the trains remain in operation.

IEC International Standards produced by a range of IEC TCs and SCs cover MEMS and other sensors, with an emphasis placed on safety and interoperability.

IEC TC 47: Semiconductor devices, and its SC 47F: Micro electromechanical systems, are responsible for compiling a wide range of International Standards for the semiconductor devices used in MEMS and other sensors such as accelerometers and temperature and pressure sensors.

Predictive Maintenance

The ability to predict when maintenance is needed reduces costs and means that it can be carried out when trains are not required to be in service, so minimizing disruption to the network.

Predictive maintenance of rolling stock and track involves using data to make informed decisions about the best time to replace and repair components, ideally before they fail. This “early warning” approach improves operational performance, keeps delays to a minimum and helps avoid the more costly repairs that occur when issues are not resolved promptly.

Italy’s primary train operator Trenitalia reported cost savings of between 8% and 10% of its maintenance bill after fitting hundreds of sensors connected to the internet on individual trains, coaches and freight cars for collecting real-time data used for predictive maintenance.

The continuous monitoring of railway tracks is also essential to the provision of timely alerts. Along with the use of GPS and embedded trackside sensors, operators in Europe and the US have used drones, or unmanned aerial vehicles (UAVs), since 2014 to supplement existing methods of track inspection. In the aftermath of Hurricane Harvey, which hit Texas in September 2017, drones equipped with high-definition cameras were deployed to survey tracks and assess which areas needed repairs.

Freight Trains Take the Strain

Using smart sensors makes rail freight operations more secure too. Sensors enable geolocation and monitor freight wagons and their contents, providing data such as interior temperature and humidity, the distances traveled and impacts the wagons and contents experience.

Triaxial acceleration sensors measure the force, frequency and precise position of the shocks that can occur during shunting and loading or unloading, and GPS sensors allow the location of each freight wagon to be determined with great accuracy. This saves costs, improves logistics planning and ensures punctual delivery. Much of this technology can be retrofitted.

These smart sensors give customers real-time data on the condition and security of goods in transit, as well as their expected arrival times. The condition of wagons and freight can be checked at any time, enhancing efficiency in the logistics chain and in the scheduling of maintenance and repair work.

The largest U.S. freight network, Union Pacific, has designed its own state-of-the art rolling stock inspection system known as "Machine Vision." This comprises an array or “portal” containing a combination of fault detection sensors, infrared cameras and line‑scan cameras, lasers and strobes. Three of these systems are in operation at different U.S. locations, collecting various types of data from wheel detectors, lasers, cameras and LiDAR (Light Detection and Ranging) technology. Each portal is able to identify and measure 22 wagon "components" and flag up defects that could lead to a delay or a derailment.

Track to the Future

SCI Verkehr forecasts that urban rail will see the strongest growth in the next decade, followed by mainline passenger traffic. Urban rail will grow at an average of 5 percent per year until 2025, with high growth rates in China and in Central and South America. Growth is expected to tail off after 2020 as many metro and light rail projects are completed.

Europe currently has the largest revenue share of the smart railway market, followed by North America. Asia-Pacific is forecast to be the fastest growing region in the next decade, with China and Japan driving the expansion of smart railway technology and services. Almost $30 billion is projected to be spent during the next 15 years on the application of IoT technology in the global railway industry, according to a forecast in August 2017 by Research and Markets, a Dublin-based business intelligence firm.

The prospect of a future in which driverless cars are commonplace could adversely affect passenger train services. “We expect autonomous vehicles to constitute a tangible threat to passenger rail within the next one or two decades regardless of the rate of adoption,” the Boston Consulting Group (BCG) said in a 2016 report.

Although some driverless metro train services currently operate around the world, these are automatic rather than autonomous. The next decade is likely to see the rail industry adopt autonomous vehicle technology more widely. This scenario envisages trains making decisions by themselves using sensors, 3D maps and real‑time data.

In October 2017, the global mining giant Rio Tinto successfully completed a 62‑mile autonomous train journey transporting iron ore in Western Australia, another step towards its vision of fully self‑driving long-distance freight train operations.

In China the CRRC (China Railway Rolling Stock Corporation), one of the world’s largest train manufacturers, is testing what it describes as “trackless trains” on the streets of Zhuzhou, Hunan Province. According to Chinese state media, the electric‑powered vehicles are a cross between a tram and a bus. They run on “virtual railway tracks” marked out by dotted lines painted on the road and use sensors to collect travel information, identify pavements and determine their own route.

If the railway industry is to compete successfully for passengers, the trains of tomorrow will have to be not merely faster and more efficient, but also comfortable and attractive to travel on.

“In future information and entertainment on trains will be more comprehensive and ubiquitous, while passengers will be better connected though satellite networks,”predicts David Briginshaw, editor-in-chief of the International Railway Journal. TC 9 already addresses this issue through Working Group, (WG) 46: Onboard multimedia systems for railways.

Smart May Present Risks

Increased connectivity also turns the rail industry into a viable target for hackers. The enormous quantity of data captured by the growing number of devices, processes and services integrated in smart railways makes cyber security a compelling issue. Operators will need to guard against cyber attacks to avoid losing control of the operational aspects of trains and of the data sets themselves.

IEC TC 9 is keenly aware of the cyber threats on railways. It takes part in work by the IEC Advisory Committee on Information Security and data privacy (ACSEC) and is in the process of setting up an ad hoc Group to address cyber issues in the railway sector.

This article is being made available to Engineering360 by the International Electrotechnical Commission, a standards setting organization.