Railway infrastructure is extensive. It reached well over 200,000 miles in the U.S. at its peak in 1916. All of that rail, or track, is comprised of many separate sections. That means there are an extraordinary number of connections. If one of those connections fails, there can be disastrous consequences. Is there an engineering solution to improving reliability? \
The danger is not hypothetical. On July 12, at a train station in Brétigny-sur-Orge, outside of Paris, a passenger train crashed at over 80 mph. The fault was a loose connection between rails. This connection is known as a fishplate.
The fishplate joins the ends of two lengths of the metal rails. In the French accident, the fishplate vibrated out of position, jamming a railroad switch open, which caused the rear of the train to move onto a different track, and an intermediary train car to swing sideways, derailing and killing seven people.
With a seemingly innumerable number of these plates, what can be done to ensure they are all functioning as they should? Currently the task is being accomplished by an army of inspectors through a slow, laborious process. The inspectors visually inspect the lines on foot or in slow-moving trucks.
Of course, when trains are running on the tracks, the inspectors cannot work and vice versa. But what if the trains could inspect the tracks as they are fulfilling their normal duties?
As explained by Pasi Lautala, head of the Rail Transportation Program at Michigan Tech, “More and more, railways are relying on ‘rolling computers,’ which may have lasers, radar, ultrasonic inspection, or different types of accelerometers that measure if there are irregularities." Not only can this technology be applied to an inspection truck, it can be used on the trains as well.
You can’t always prevent failures, but early detection of abnormalities can be just as valuable. Although railcars can be improved to handle derailment, preventing the derailment is much preferred. The monumental task of keeping tabs on hundreds of thousands of miles of railroad track can be simplified and automated through on-board inspection systems. This means a more timely response, lower cost and greater safety. Now if they only had a system to detect and repair potholes.
Images courtesy of: Popular Mechanics and ENSCO