High-Speed Rail Track Inspection Systems Based on the Ultrasonic Method

The safety and reliability of rail transport depend largely on the condition of the tracks. Defects that develop in rails during operation, including those caused by wear, corrosion, repeated load cycles, and various mechanical impacts, can progress from minor to significant and eventually become critical. These critical defects may result in rail breakage under a moving train, so they require immediate attention. Therefore, it is essential to regularly inspect the tracks using ultrasonic high-speed rail testing Systems. These Systems can detect all types of rail defects at different stages of development according to AREMA, EN 16729-1, and UIC 712-R norms. They can also determine the geolocation and depth of the occurrence of defects. This allows for timely repair or replacement of rails before defects reach a critical stage and threaten operational safety..

Application of Ultrasonic Rail Inspection Vehicles

High-speed ultrasonic (UT) rail testing Systems are installed on hi-rail vehicles, inspection trains, and self-propelled inspection cars. These testing machines provide rapid rail flaw detection for railroads and metro lines. While in motion at operating speeds, they scan both rails and welds of the track and collect data on their condition.

Ultrasonic immersion probe units, which are installed on the rail-mounted testing trolley, automatically transmit signals to the software of the railway inspection System. Built-in algorithms in this software analyze the data, detect potential rail defects and their geolocation, and send appropriate different signals to the NDT technician. This automated signal processing minimizes human influence on the outcome of the inspection and improves the effectiveness of detecting defects in rails.

High-speed test Systems integrated with vehicles are especially effective for nondestructive testing (NDT) during inspections of extended and heavily used rail tracks. If necessary, the vehicle carrying the rail flaw detection System can exit the tracks at any crossing to allow a train to pass. Then, it can drive back and continue the ultrasonic rail inspection.

The NDT Technician's workplace and the electronics of the System are located inside the vehicle body, enabling UT inspections in any weather condition.

Advantages of High-Speed Rail Testing Machines

• Continuous rail testing: High-speed inspection machines, cars, and vehicles enable nondestructive testing of railway tracks at speeds of up to 25 mph (40 km/h), minimizing disruption to train schedules.
• Economic Efficiency: high-speed Systems significantly reduce the cost of nondestructive inspection per mile of railway track compared to hand-pushed rail flaw detectors. These Systems inspect rails ten times faster and reduce labor requirements, as only two to three people are needed to operate them: truck driver, an NDT technician, and an assistant technician.
• Versatility: The design of the rail testing trolley of the high-speed System allows it to be used either as a trailer for a road-rail vehicle or mounted under an inspection train or self-propelled cars.
• Comprehensive inspection: In addition to ultrasonic testing (UT), eddy current rail testers (ET) can be installed in the high-speed System to detect hardening cracks and other surface defects in railway rails. If necessary, the System can be supplemented with a track geometry and rail profile measurement System.
• Compliance with international and national standards: The detection of rail flaws complies with the nondestructive testing standards of the American Railway Engineering and Maintenance-of-Way Association (AREMA), the International Union of Railways (UIC 712R), and EN 16729. Additionally, the System can be adapted to meet the customer's national standards.

Economical types of high-speed rail track inspection Systems

One of the most cost-effective and easy-to-maintain rail track inspection Systems is one integrated into a hi-rail vehicle, such as a pickup truck or a box truck.

• Heavy-duty pickup truck with inspection trolley: equipped with reinforced chassis components and a hydraulic system for the inspection trolley to be lifted and lowered. Its design allows for quick installation of the trolley onto the rails and towing during ultrasonic testing (UT) of the railway. After testing, the trolley is lifted back up using the hydraulic system and transported by the pickup truck.
• Box truck with inspection trolley: it has a spacious box that is equipped with a workplace for the NDT technician and a parking space for the inspection trolley. The driver uses a hydraulic mechanism on the rail flaw detection System to lower the trolley onto the rails and lift it back into the box after the UT inspection.

Conclusion and Proposals for Cooperation

Integrating high-speed ultrasonic testing Systems into railroad inspection machines, trains, and trucks allows for the systematic identification of critical rail defects in railway tracks and metro lines. This process also promotes the prediction of defect progression and the timely elimination of such defects.

OKOndt GROUP invites companies interested in advanced hi-rail vehicles equipped with hi-speed rail flaw detection systems to collaborate. Contact us for expert advice on selecting the most suitable NDT solution for your railway inspection needs.

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