Extreme temperatures can cause train track misalignment, buckling and breaking leading to passenger and freight train delays and derailment while incurring costly track repair and replacement. Early detection and reporting of transit track shifting, and extreme temperatures will alert transit technical staff to take timely action to avoid damage to rail track and cause long transit service disruptions requiring days of costly repair. According to Transport Policy Journal, heat-induced delays to passenger and freight trains in the United States incur costs anywhere between 25 billion to 60 billion dollars every year. According to the Federal Railroad Administration, lateral thermal buckling is a common cause of derailments in continuously welded rail (CWR) tracks. Since CWR tracks are constrained against the motion along the direction of travel, extreme temperature changes can induce compressive stresses in the rails that can lead to track buckling. There have been 5,977 rail accidents within the United States in the last three years. In a buckling situation, the length of repair and readjustment can be quite large.
To minimize the costs of repair and assure the safety, there is a high need to develop techniques for avoiding thermal buckling in rails. Despite a large amount of research in this area, the prediction of rail thermal buckling remains a major issue because of the nonlinear nature of the phenomenon and the large number of parameters affecting the problem. The proposed portable Magnetic Rail Movement Measuring Device (MRMMD) has a high potential to meet this need and would transit and rail agencies with early detection and timely alert to avert damage and costly repairs.
The proposed solution to prevent the thermal induced problem from occurring is a system comprising a Magnetic Rail Movement Measuring Device that offers an entirely new method to portably measure true rail temperature and its lateral and vertical movements using laser-based and temperature sensors in real time and a new cloud-based data communication system to communicate measurement data to any control center or smart device providing timely alerts so that preventive action can be taken before damage to tracks and train derailment could occur. Currently there is no method available to accomplish this in real time.
The MRMMD magnetically attaches to running rail and enters sleep mode between trains. Approaching trains activate MRMMD and, under load, horizontal rail push and vertical track pumping are measured and recorded. The device retains maximum movement and alerts can be sent when preset tolerances are reached such as when rail temperature reaches a predetermined limit and again when it goes below that limit. The cloud-based data is accessible from any laptop and the MRMMD is Bluetooth accessible.
The developed system’s feasibility will be implemented by demonstration to the transit agencies. Six prototypes of the system will be developed and tested in collaboration with the Transit agencies of Pennsylvania and Maryland. Both transit agencies are on board to evaluate the device in actual operations.