Train inspection system

Worn or broken parts can drag, pound, and generally destroy the cars and the track structure they run on.

As the railroad has evolved from block stations and control towers to a centralized dispatching system, they have also moved to more advanced inspection tools.

The technologies in use today vary from a simplistic paddle and switch to infrared thermography, laser scanning, and even ultrasonic audio analysis.

[1] The systems used on North American and other railways fall into a dozen or so major groups, some are listed below.

[3] Looks for hunting oscillation of the trucks or wheelset; a lateral movement in the gauge of the track, like drifting back and forth in a lane of traffic.

This action can increase above a certain speed to the point the wheel flanges impact the rails, potentially causing damage to both.

Is stiff or poorly steering or axle sets that don't follow the path of the track correctly.

[4] Listens with special microphones for internal bearing defects as the equipment moves across the detector.

If an alarm is sent, the train is stopped, and either the defect is corrected or the offending car is removed for repair.

These are able to measure the height and width of rolling stock, so that cars and loads which won't fit under bridges or through tunnels are stopped.

Mounted on poles or a bridge structure, the optical line is adjusted for a set height and width, it can then send an alarm when something too big to fit the clearance limits ahead passes its view.

These back office systems are predictive, finding equipment problems as they start to develop.