This research evaluates the current legally mandated train air brake test within Canada and provides further comparison with a technology driven approach used by Canadian Pacific known as Automated Train Brake Effectiveness (ATBE). The current No. 1 Air Brake Test mandated by Transport Canada is performed on static trains as opposed to the technology-driven approach applied to moving (dynamic) trains using wayside detectors, namely wheel temperature detectors (WTD) and automated equipment identification (AEI).
ATBE triggers both Hot and Cold Wheel alarms based on designed detection site locations. Flat locations aim to verify that no excessive wheel temperatures (hot wheels) are present within passing trains. These sites are located where no brake application is needed and serve to identify complete train air brake release. Hot wheels can be indicative of hand brakes left on, sticking brakes, or other braking system defects. Contrarily, hills/grades where train air brakes are intentionally applied while descending to control speed are used to evaluate ineffective brakes. Wheel temperatures measured below threshold or “cold” in comparison to the train average temperature suggest ineffective braking on the corresponding railcar as identified by AEI. Railcars with cold wheels or hot wheels not caused by hand brakes are Single Car Air Brake Tested and repaired prior to return to service.
In this work, detection rates of both inspection methods together with the reliability of these methods to identify air brake failures are assessed. Maintenance records of railcars which failed air brake inspections are checked for the repairs associated with the brake defects which would cause cold or hot wheels. Additionally, methods to assess the impact of dynamic braking on the ATBE process are discussed.
Research has shown that ATBE has considerably higher alarm rates than the manual air brake test. As both inspection methods are able to identify not only air brake failures, but also defects not related to air brake systems, an inspection which results in increased railcar repairs suggests improved fleet health.