Rail inspection

Every year, North American railroads spend millions of dollars to inspect the rails for internal and external flaws.

In 1927, Dr. Elmer Sperry built a massive rail inspection car under contract with the American Railway Association.

This was done by passing large amounts of the magnetic field through the rail and detecting flux leakage with search coils.

A list of methods used to detect flaws in rails: The techniques mentioned above are utilized in a handful of different ways.

The probes and transducers can be utilized on a "walking stick", on a hand pushed trolley, or in a handheld setup.

Induction and ultrasound methods can be used in rail inspection cars and operate at testing speeds of more than 30 mph (48 km/h).

These trucks are loaded with high-speed computers using advanced programs which recognize patterns and contain classification information.

The GPS system allows a follow-up car to find precisely where the flaw was detected by the lead vehicle.

One advantage to the HiRail trucks is that they can work around regular rail traffic without shutting down or slowing down entire stretches of track.

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.

Other advancements could include neural network analysis of signals to improve defect detection and identification and longitudinal guided ultrasonics.