With the UK government committing £10.2 billion to rail infrastructure enhancements in its June 2025 Spending Review, the focus is firmly on expansion. Here, Andrew Keith, division director at load bank manufacturer Power Prove, explains how load banks provide essential support for both building and maintaining resilient rail networks.
In its State of the Nation 2025 report, the Institution of Civil Engineers (ICE) warned that key parts of the UK’s rail network — particularly power and signalling systems — may not be as resilient as previously assumed. As the Government plans and moves forward with new rail lines, upgraded stations and advanced digital systems, the underlying electrical infrastructure will be placed under even greater strain.
This presents two core challenges: integrating modern electrical assets safely into the network and ensuring that ageing infrastructure can withstand the increased operational load. Load banks help to make this possible.
Supporting expansion
To help timetable more trains, improve safety and implement digitally controlled signalling hubs, supervisory control and data acquisition (SCADA) systems, low-voltage transformers and traction power substations are being deployed across the rail network.
However, these modern systems are more sensitive than their predecessors and risk placing greater demands on electrical infrastructure.
To prevent disruptions or failures, their performance must be thoroughly validated before they go live. Load banks aid this process by applying controlled, simulated electrical loads to the system, enabling engineers to test key parameters such as voltage stability, frequency regulation, harmonic distortion and transient response under real-world operating conditions.
For example, diesel generators must demonstrate stability across dynamic load changes, while uninterruptible power supply (UPS) and battery systems must facilitate critical loads without voltage sag or switchover delays. By gradually increasing or cycling loads, the load bank reveals how systems respond to stress, helping ensure continuous backup power for safety-critical functions like signalling and control during faults or outages.
Load bank testing also helps ensure compliance with standards such as the IEC 62040 series for UPS systems, which requires full-load testing using defined reference loads.
In contrast, EN 50388 for power supply and rolling stock doesn’t explicitly require load bank testing. However, it does require verification of traction power supply performance under real operating conditions. Consequently, load bank testing is recognised as an effective method to validate this requirement, providing a foundation for resilient, future-ready infrastructure.
Maintenance under load
While new projects are vital, much of the UK’s rail network still relies on decades-old substations, cable networks and backup systems. This infrastructure must now handle tighter service intervals; higher passenger loads and digital system interfaces — all without compromising safety or uptime.
Here too, load banks provide critical assurance. Portable and containerised units enable the live testing of installed diesel generators, switchgear and batteries without interrupting operations. For example, a resistive load test can reveal engine instability in an ageing genset, while a capacitive battery discharge test may show cell degradation that would threaten UPS runtime.
By identifying performance drift before failures occur, load bank testing enables predictive maintenance strategies. Remote-controlled load bank systems, such as DigiLoad, allow engineers to conduct off-site load profile programming, monitor system responses in real time and capture data for analysis. These capabilities are particularly valuable in rail environments where access to critical electrical infrastructure is limited to short maintenance windows or remote substations along active lines.
Ultimately, this enables safe integration of new components into legacy infrastructure. Without proper validation, combining modern and ageing systems risks voltage imbalance, power quality issues or unexpected load behaviour — all of which could impact safety-critical operations. By simulating operational stresses, load banks verify that upgrades do not undermine existing resilience, ensuring that modernisation efforts enhance rather than disrupt reliability.
Rail expansion is central to the UK’s ambitions, but it cannot come at the expense of reliability. By validating electrical performance under real-world conditions, enabling predictive maintenance and enabling the safe integration of new and legacy assets, load banks are essential to powering the next era of rail transport — safely, reliably and resiliently.
Power Prove is a manufacturer of load bank systems, including the remote-controlled Digiload platform. Get in touch today to find out how we can assist your next project.
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