Rivelin Rail
We Built a Track Trolley That Logs Rail Friction and Controls Water Spray
Railway track trolley integrating a friction measurement sensor, water spray system, and SD logged GPS and friction data
ProtoGT accessing the trolley electronics enclosure during build and test.
The Challenge
Rivelin Rail needed a track trolley that could integrate their friction measurement sensor and collect data under different environmental conditions, complete with a pumping system to spray water onto the rail at adjustable flow and pressure. The solution? A railcart that operators can simply push along the track whilst the system detects friction points in real time. The result is a massive boost in coverage and efficiency, with continuous measurement over extended lengths replacing the old manual approach.
ProtoGT installing the friction measurement sensor on the trolley assembly.
Our Approach
Control and Logging
At the heart of the system sits a Raspberry Pi Zero W, handling all the control work. It acquires friction data alongside GPS positioning, combining the datasets and storing everything on an SD card. The whole setup lives inside a rubber-sealed 3D-printed enclosure to keep the electronics safe from the elements.
Spray System
The trolley features an integrated pumping system that sprays water onto the rail at adjustable flow and pressure. Replaceable nozzle tips let operators switch between different spray angles and flow rates depending on testing requirements, with built-in pressure regulation ensuring consistent performance.
Precision Positioning
An adjustable bracket mounted on linear rails keeps the friction sensor accurately aligned across the track width. This design accommodates variations in track geometry whilst maintaining precise and repeatable sensor positioning at the required target location throughout testing.
Modular Design
Custom mounts for the battery and water tanks make refilling, charging, and maintenance straightforward. Quick-release mechanisms mean operators can swap components without tools. The bespoke electronics panel integrates all control and logging hardware into a compact, weatherproof layout that's built specifically for outdoor railway environments and the customer's operational needs.
Documentation Package
The client received comprehensive technical documentation covering mechanical and electronics design, along with a detailed user manual. This includes guidance on operation, nozzle switching, pressure regulation, routine maintenance, and verification procedures.
ProtoGT directors Ed George and Will Toms presenting the the Rivelin Rail track trolley prototype
The Result
The final system is a track trolley platform that records friction data alongside GPS positioning, storing everything locally on an SD card for later analysis. It includes a controlled water spray system with adjustable pressure and interchangeable nozzle options, allowing operators to test under different surface and environmental conditions. This combination of precise data logging and flexible spray control makes it possible to assess track friction across various operating scenarios.
Client Feedback
The client was satisfied with the delivered system and documentation package. The solution met the project requirements and provided a practical improvement over their previous measurement method.