MOBILE INSPECTIONS OF RAILWAY WHEELS WITH UFPE AND ITS LIGHT VERSION

摘要

Curved tracks, different stresses of load, wear and fatigue are potential challenges to cause a failure while the railway operates. Non-destructive testing with ultrasonic systems is a preventive method to inspect the wheels while they are mounted to the train. To bring down the cost of dismantling during maintenance and improve the service performance it is useful to place a mobile test rig underneath the train, between or beside the rail. With UFPE (underfloor testing equipment) and UFPE-light, currently Deutsche Balm AG uses mechanized systems for driving- and carrying wheels with phased-array technology and standard probes to prevent a defect while the railway is operating. In 2000, the Deutsche Bahn AG started the ultrasonic testing for wheels in mounted position. This conventional method includes a V-transmission with standard probes. These probe holders had an enormous dimension and it turned out to be very difficult to get it between the wheel housing, wheel and rail. To achieve a higher availability of trains and lower test time, wheels had to be tested by special mechanized test equipment. After introduction of a new maintenance concept for ICE trains in 2004, new UFPE were ordered and UFPE-Light, an innovative light version of UFPE from DB Systemtechnik GmbH, was supplied to the market. With this new version the testing procedure was simplified and the testing time for one wheelset could be reduced to 10 min. Several economic and security reasons suggest the need for the inspection of high speed trains and carriage wagons. The advantages of novel (non-destructive) technology compared to traditional maintenance are as follows: (1) Reducing the time of testing and maintenance (2) Obtaining reproducible testing results (3) Automated electronic documentation of results (4) Adaptable to new wheel parameters (5) Accessibility of wheels without dismantling of components (6) Consistent sensitivity over all wheel sets by using an adjusting device Today, ten years later, the checks are mainly done at night to prevent an additional immobilization time. In the meantime, while everything is done on and inside the train, wheelsets are tested simultaneously. Only qualified inspectors in ultrasonic testing are admitted by DB Systemtechnik GmbH to the instruments and applications. The system sensitivities are set to any category of wheels and due to the training of employees, small cracks, damage in the material and even production-related failures have been detected in the past.