Case Study 1999. Rail locomotive weigh-in-motion


Weighwell Ltd


To develop and trial an optical fiber sensing system to measure the weight of rolling stock at operating speeds.


SmartPatch sensors were attached to rail sections and calibrated via static loading. Dynamic measurements were taken with a locomotive pulling known loads over an instrumented section of rail at increasing speeds.

Results showed that the system responds faithfully to applied load, although the speed and resolution of the then state-of-the-art instrumentation (Smart Fibres’ OFSSS I) limited the accuracy of weighing at high speeds.

Current day instrumentation, being two orders of magnitude faster and an order of magnitude higher in resolution, makes for a technically viable rail weigh-in-motion solution.

Top left Image Below  - Calibrated load approaching instrumented section for dynamic testing.
 Middle Image Below  - Calibrated load on instrumented section
 Right Image Below  - Sensor attachment to operating rail
Lower Left Image below  - Static load testing


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