Q&A with Chinmay Sankhe

Q: Welcome to the team, Chinmay. Thanks for joining us. So tell us – what is rolling stock signalling interference compatibility testing?

Chinmay: When rolling stock is introduced to a railway network, it must be tested to ensure it can communicate properly with the existing signalling system. This process is called Signalling Compatibility Testing, and it’s crucial for safe and reliable train operations.

Q: Why is it needed?

Chinmay: Every railway network has its own Signalling infrastructure, which includes track circuits, DPUs, Treadles, axle counters, balises, and radio-based systems. These systems detect, track, and control train movements to prevent collisions and ensure efficient scheduling.

Since different rail networks may use different signalling technologies, a newly introduced train must be tested to ensure it can interact correctly with these systems without causing faults or malfunctions.

Q:  What are the key objectives of this testing?

Chinmay: We take a look at few key areas when evaluating rolling stock:

• Verify Train Detection – Ensuring the train is accurately detected by the track-based signalling systems (e.g., track circuits and axle counters).
• Assess Interference Risks – Checking if the train’s electrical and magnetic emissions interfere with existing railway infrastructure.
• Validate Onboard Signalling Equipment – If the train has an onboard signalling system (e.g., ETCS, CBTC), it must function seamlessly with the network.
• Confirm Safe Stopping and Movement Authority – The train should respond correctly to signal aspects, speed restrictions, and automatic train protection (ATP) systems.
• Wheel-to-Wheel Resistance Testing – Ensuring proper current flow through the train’s wheels so that track circuits register the train’s presence correctly.

Q:  What got you interested in this area of engineering?

Chinmay: When I first started working in rail, the opportunity came my way, and I took it with an open mind. But once I got involved in Signalling projects, I realised this wasn’t just another job—it was something I genuinely enjoyed.

The mix of engineering challenges, real-world impact, and the complexity of integrating modern trains into diverse networks pulled me in. There’s something fascinating about ensuring that a train—loaded with cutting-edge technology—can safely and efficiently run on tracks designed decades ago. From signal interactions to vehicle behaviour and safety validation, every project brings a new puzzle to solve, and that’s what keeps it exciting.

What I enjoy most is the fact that my work directly contributes to safer and more efficient rail networks. Whether it’s troubleshooting a compatibility issue, analysing test results, or ensuring compliance with railway standards, it’s all about making sure trains run smoothly and reliably. And now, looking back, I can confidently say I wouldn’t have it any other way!

Q:  What do you hope to bring to Rail Confidence’s clients through this work?

Chinmay: Rail Confidence has recently expanded into the Signalling Interference Compatibility Testing area, and we’re all excited to deliver high-quality services and valuable technical insights to our clients.

Every Signalling Compatibility Testing project comes with its own set of challenges—each new rolling stock is unique, making it a complex task to ensure that a vehicle meets Signalling requirements or to validate its system performance. Through my work, I aim to provide clients with clear insights, thorough assessments, and detailed reporting, ensuring safe, efficient, and compliant railway operations.

Beyond the technical aspects, I strive to bring a collaborative mindset—working closely with clients, operators, and suppliers to streamline testing, reduce risks, and optimise project outcomes. Ultimately, we want our clients to have the confidence that their rolling stock will integrate seamlessly into existing networks, with minimal disruptions and maximum reliability.

Q:  What’s something people are surprised to know about your work?

Chinmay: One thing that surprises people about Signalling Compatibility Testing is how much real-world railway operations and physics come into play. Many assume it’s just about ensuring trains respond to signals, but in reality, it involves a deep dive into electromagnetic interference, train detection principles, and system interactions—things that aren’t always visible but are critical for safe operations.

At the end of the day, what seems like a simple green or red signal is actually the result of complex engineering, rigorous testing, and seamless system integration behind the scenes—and that’s what makes the job so interesting!

Q:  How do you see signalling compatibility testing evolving in the next decade?

Chinmay: The next decade is set to bring major advancements in signalling compatibility testing, driven by technological innovations, digitalisation, and automation. As rail networks transition towards modern Signalling systems such as Axle Counters, ETCS (European Train Control System), and CBTC (Communications-Based Train Control), compatibility testing will need to adapt to increasingly complex system integrations.

Additionally, the industry is working towards harmonising rail signalling standards, aiming to reduce variations in trackside infrastructure and create a more seamless and interoperable railway network.

What I enjoy most is the fact that my work directly contributes to safer and more efficient rail networks.

Chinmay Sankhe