Inspection Rail On Duty in warm noon.
6Inspection Rail On Duty in warm noon.

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Rail inspection
Rail inspection is the practice of examining rail tracks for flaws that could lead to catastrophic failures. According to the United States Federal Railroad ...

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The first rail inspections were done visually and with the Oil and Whiting Method (an early form of Liquid Penetrant Inspection). Many sources cite that the need for better rail inspections came after a derailment at Manchester, New York, in 1911. That particular accident resulted in the death of 29 people and injuries to 60 others. The investigation of the accident revealed that the cause was a transverse fissure (a critical crack that lies perpendicular to the length of the rail) in the rail. Further investigation in the late 1920s showed that this type of defect was quite common. With increased rail traffic at higher speeds and with heavier axle loads today, critical crack sizes are shrinking and rail inspection is becoming more important. In 1927, Dr. Elmer Sperry built a massive rail inspection car under contract with the American Railway Association. Magnetic induction was the method used on the first rail inspection cars. This was done by passing large amounts of the magnetic field through the rail and detecting flux leakage with search coils. Since then, many other inspection cars have traversed the rails in search of flaws. In 1949 ultrasonic flaw detection was introduced by Sperry Rail Service (Named after Dr. Elmer Sperry), by the 1960s Ultrasonic Inspection Systems had been added to the entire Sperry Fleet. Rail inspection continues to advance to this day. Companies like Sperry Rail Service, Nordco Inc, Herzog Rail Testing, and many others continue to develop an ever-increasing array of technologies to detect internal flaws.
With increased rail traffic carrying heavier loads at higher speeds, a quicker more efficient way of inspecting railways is needed. Lasers inspect railway geometry, but one day they might be utilized as a form of non-contact evaluation of the rail. This most likely will be done with laser-optical transmitting transducers in ultrasonic testing. Eliminating contact with the rail could one day allow high-speed detection of flaws. (Testing of rail is currently able to be done at 80 km per hour with a Speno US-6 Ultrasonics train) Another need for the future is a complete rail inspection system. A step in this direction is a deeper investigation of the rail by using low-frequency eddy currents. Other advancements could include neural network analysis of signals to improve defect detection and identification and longitudinal guided ultrasonics. Improved rail quality, composition, and joining techniques could lead to better wear characteristics and a longer lifespan of the rail. Some investigation into banitic steels looks promising. A safe and portable means of filmless radiography could assist with onsite defect evaluation. These are just a few advancements in the process of being developed for future use.