Train inspection system

The train inspection system is one of the various inspection systems necessary to maintain the safe operation of rail transit.

Because safety is so important when train cars cross the tracks, inspections are a must.These cars are heavy and have the potential for damaged or defective moving parts.Worn or broken parts can drag, hit and generally destroy the car and the track structure it runs on. Parts and loads must not extend beyond the scope of the car, and the contents of the car must not leak.Quality checks are required not only before the train moves, but also as the train travels to its destination.

Overview 

There are several levels of inspection of railway equipment.Inspections are continuous,beginning when the car is built, and repeated at regular intervals.Before the train begins its journey, the locomotives and carriages are inspected.This is done by staff in the mechanical department, sometimes with cameras and scanners.Some of the items certified for use include brake systems including handbrake release, brake application, condition of air valves, pipes and hoses, communication equipment, and more.Much like a checklist an airline might use.After the pre-departure work is completed, the train can travel safely.Once the movement begins, the trains will be continuously monitored by staff, scanners and monitors.These are sometimes called "motion defect detectors" or defect detectors (DD).

Technologies

As railroads evolved from blockade stations and control towers to centralized dispatch systems, they also turned to more advanced inspection tools.Technologies in use today range from simple paddles and switches to infrared thermal imaging, laser scanning, and even ultrasonic audio analysis.These devices are used to check the engine, the car and its load.The systems used on North American and other railroads are divided into a dozen major groups, some of which are listed below.

Wheel Impact Load Detector (WILD)

A high-impact wheel has defects where it doesn't roll smoothly along the track, and defects in the wheel can cause vibrations or bumps.This is very destructive to the track structure and rolling stock.

Weigh in motion (WIM)

Truck hunting

Look for oscillations in the truck or wheelset; lateral movement of the track gauge, like drifting back and forth across the lane.This action may increase above a certain speed until the rim hits the rail, potentially causing damage to both.The force absorbed by this action also affects the energy consumption of the train running.

Truck performance

Stiff or poor steering or the axle group not following the track path properly.Like "dog tracking," the truck runs off the flange on one side or the other.Truck performance deficiencies include tracking position and angle of attack for each axle, as well as rotation, shifting, axle misalignment and tracking errors between each bogie.Truck performance detectors can provide early detection of bogie defects and early warning of derailment risks through flange climb or rail breakage.