A year‑long trial led by Knorr‑Bremse Rail Systems UK and Chiltern Railways, with support from Angel Trains, has delivered groundbreaking interim findings that could transform the rail industry’s understanding of low‑adhesion conditions. The results were unveiled this week at the ADHERE (ADHEsion REsearch) Seminar in Birmingham.
The Low Adhesion Monitoring System, developed by Knorr‑Bremse and jointly engineered with Chiltern Railways, has been installed on Class 165 unit 165004, the first train of its type to run with the technology. Operating across the Chiltern Main Line and London–Aylesbury route, the unit has been capturing high‑resolution, real‑time data since entering service in September 2025.
88,000 Miles of Groundbreaking Data
Over the course of the trial (to 4 February 2026), the FiC test unit has:
- Travelled more than 88,000 miles
- Logged 500+ wheel slide events
- Recorded 850 traction slip events
- Identified proportionately more slides when running as a single unit
- Captured detailed seasonal and weather‑related adhesion variations
Crucially, the system operates without affecting any existing onboard systems, providing unprecedented visibility into braking behaviour, infrastructure influence and geographic adhesion “hot spots”.
A First for UK Rail: Calculating True Adhesion at the Point of WSP Activation
The project marks the first time UK rail experts have been able to calculate actual wheel‑rail adhesion values at the moment Wheel Slip Protection (WSP) activates — moving the industry beyond assumptions and broad indicators.
John May, Digital Services Business Development Manager at Knorr-Bremse Rail Systems UK, said:
“This trial marks a significant milestone in how the industry understands and manages low adhesion. For the first time, we are able to move beyond assumption and inference to calculate real, in-service adhesion values at the point where Wheel Slip Protection is active.”
“By working with Chiltern Railways and our industry partners, we are building the foundations for a more proactive, data-led approach to improving braking performance, safety and operational resilience across the network. The trial helps train operators and Network Rail understand when and where there is low adhesion in near real time. Hot spots of low adhesion can be identified so that drivers can be made aware and rail head cleaning can be planned.”
Supporting National Research and the Rail Industry’s Autumn Challenge
The data is already feeding into the RSSB’s Adhesion Research Group (ARG), with additional analysis underway by Knorr-Bremse and the University of Huddersfield to enhance precision in real‑time adhesion calculations.
Louis Schmandt, Technical Engineer at Chiltern Railways and ARG member, said:
“This trial is a significant step towards ARG’s goal of developing a first in class ‘adhesion expert train’ that is able to accurately predict the low adhesion risk of any location at any given time throughout the year to a very high degree of accuracy.
“Notably, data is not just being captured during the Autumn season, but all year round and for the first time, adhesion levels are being monitored outside of the limiting thresholds of WSP activity, providing a much more complete overall picture. This brings the potential of being able to target low adhesion mitigation measures more effectively as well as better inform driver behaviour during the Autumn, possibly eliminating the need for Autumn leaf-fall timetables.
“In the long term, there is the potential to feed this low adhesion data as an additional input into WSP systems to enable them to work more proactively, anticipating when a WSP activation might be initiated rather than reacting to a deviation in speeds across different axles. This trial ultimately forms part of the industry’s broader goal of creating a seasonally agnostic railway, where there is no negative impact on railway performance and safety during the Autumn season and the ancient problem of ‘leaves on the line’ is firmly consigned to the history books.”
Next Steps: Potential Network‑Wide Expansion
If the system continues to deliver high‑value insights, Knorr‑Bremse, Chiltern Railways and Angel Trains hope to extend the trial to additional operators later in 2026, with a possible fleet‑wide rollout beginning in 2026/27.
Image credit: Knorr-Bremse
