At the annual Railway Research and Training Review (RRTR), hosted by the University of Pretoria, Professor Hannes Gräbe delivered an insightful presentation, emphasising that digital railway transformation is not just about technology—it is fundamentally about people. While digitalisation often conjures images of artificial intelligence, automation, and high-speed data processing, Gräbe stressed the misconception that digital railways are solely about automation and numbers. Instead, digitalisation in rail involves integrating people, ideas, and technology to create a more efficient and sustainable railway system.
A key objective of their research is to integrate various aspects of railway technology while keeping people and systems at the core. One of the main areas of focus is smart railway monitoring, a field that has been developed over many years. In engineering, there is a common principle: “If you cannot measure something, you cannot manage it.” Even if measurement is possible, without proper analysis and action, management remains ineffective. This highlights the importance of not only measuring but also understanding and effectively utilising data in railway operations.
The evolution of sensors and monitoring technologies has significantly transformed this process. When the research initially began, high-quality sensors were expensive and required careful handling. They were stored meticulously, maintained in pristine condition. Today, however, these same sensors are far more affordable, allowing for widespread installation. Instead of preserving them for selective use, they can now be deployed extensively, replaced as needed, and even discarded once they have served their purpose. This shift has fundamentally changed the approach to railway monitoring.
The University of Pretoria’s test track remains a vital part of this work, providing a controlled environment for research and experimentation. It features multiple track configurations, including conventional track, slab track, and Tubular Modular Track (TMT). This space serves as a practical testing ground for real-world railway applications.
Additionally, the Engineering 4.0 facility houses laboratories where a significant portion of railway research takes place. This includes rail testing, cyclic loading experiments, and accelerator testing. Condition monitoring is a central focus, and access to specialised equipment, such as a road-rail vehicle and a track geometry car, enhances research capabilities. These tools, combined with LiDAR technology, allow for exploration into a wide range of railway challenges, from track geometry assessments to vehicle and animal collisions.
The integration of LiDAR, drones, and sensors enables advanced calculations, such as slope and clearance measurements. One practical example of this research is the study of animal crossings over railway lines, a critical issue in railway safety and environmental impact.
However, as technology advances, the sheer volume of data generated presents a new challenge—managing and interpreting big data. While it is essential to collect data, the ability to extract meaningful insights is even more crucial. To address this, machine learning applications are being explored. One of the ongoing projects involves using vehicle acceleration measurements to predict track geometry. Measuring vehicle accelerations is relatively straightforward using an Inertial Measurement Unit (IMU), but extracting track geometry data from these readings requires advanced analytical techniques.
Through ongoing research, relationships between these variables are being established, ultimately refining predictive maintenance strategies and improving overall railway efficiency.
One example of SMART 24/7 monitoring is a research project currently being conducted for Gautrain. This initiative was largely driven by Dr. Andre Broekman, who played a pivotal role in designing and integrating a network of sensors to monitor railway infrastructure. The system is fully operational, and the research team is proud of its effectiveness in real-time railway condition monitoring.
The monitoring system incorporates various sensors that measure accelerations and deflections on the track. In addition, it includes sensors that measure sleeper deflection and temperature variations, providing valuable insights. This data has allowed researchers to identify significant trends in track behaviour in response to temperature changes. The deflection measurements can also be used to analyse frequency responses, allowing researchers to identify unique behaviour patterns, often referred to as fingerprints.
Additionally, sensors installed on sleepers capture a range of structural parameters. The research team has partnered with TANDM, which has introduced new technologies, significantly enhancing the project’s capabilities. These sensors contribute to a comprehensive dashboard system, where the collected data is visualised for real-time analysis.
It operates on a solar-powered setup and utilises multiple communication networks to ensure uninterrupted data transmission.
At its core, this system is focused on structural health monitoring, as well as broader railway performance assessments. Data is continuously gathered from multiple monitoring sites, tracking every train that crosses specific points along the network. By leveraging continuous monitoring, sensor networks, and real-time data analysis, this research is contributing to the development of more efficient, safe, and data-driven railway operations.
Research into fibre optic sensing technology is currently underway, focusing on the use of strain and temperature sensors. Implementing this system presented several challenges, but ultimately, a fibre optic cable was successfully attached along the rail’s neutral axis.
The fibre runs continuously along the rail, connecting pre-manufactured strain and temperature sensors at designated sites. These sensors provide dynamic measurements while also enabling long-term data collection.
This research is centred on measuring longitudinal rail stress, a critical factor for civil engineers addressing kick-outs and rail breaks. Continuously welded rail is particularly sensitive to temperature fluctuations, making stress monitoring essential. Given the role temperature plays in these issues, the feasibility of fibre optics for stress measurement and rail break detection is being explored.
Taking Research Project Collaboration in SADC
An international research project in collaboration with the University of Birmingham is focused on rail interoperability in Southern Africa. This large-scale initiative is being conducted in partnership with the Southern African Railway Association (SARA) and is funded by the UK government’s Foreign, Commonwealth & Development Office.
The project aims to assess the capabilities and current state of railways across the SADC region, with a particular focus on improving interoperability. Key objectives include understanding how these railway systems integrate into the SADC Rail Master Plan, identifying skills development needs, and exploring opportunities to enhance cross-border trade and business.
The research is currently in the data-gathering phase, collecting information from railway operators across the region, including Transnet, which is compiling relevant data packs. The study covers multiple aspects, from existing knowledge levels to performance capabilities, providing a foundation for strategic improvements in regional rail operations. This research is directly tied to efforts to create a more efficient and interconnected railway network across Southern Africa.
A Call for Industry Support
As Professor Hannes Gräbe concluded his presentation, he issued a call to industry to support the University of Pretoria in realising its ambitious vision for the establishment of a test track. This facility would provide training opportunities, hands-on experience, and real-world applications for railway research in a controlled, operationally independent environment.
However, bringing this vision to life depends on securing the necessary resources to turn these commitments into reality. Organisations interested in contributing to this initiative are encouraged to contact Professor Gräbe to explore how they can play a role in making this project a success.
