DECATUR -- The crossing guard on Roller Avenue in Decatur dropped temporarily, blocking the crossing as workers from Kansas City Southern Railroad performed track inspections and repairs near the Decatur Depot Museum Thursday.

Because of the recent six-week-long extreme heat wave that gripped the middle part of the country in June and July, work crews periodically travel the rails with electronic detection gear looking for cracks and any warping in the rails. One of the items that these crews look for is a phenomenon known as a sun kink.

A sun kink occurs in extreme heat, usually 90 degrees or hotter, when the track buckles or warps.

In the early days of railroads, the track was laid in 39-foot increments which gave room for the track to expand. Rails need room to expand, and since they were held together with a bolt plate and four heavy-duty nuts and bolts, this gives the track the needed room to expand.

By 1933 some railroads began welding the track together, using a process called Thermite welding to connect one piece of track to another to form a continuous rail. By 1980, this method of connecting the track was used to hold 80,000 miles of track together in the United States. But the smother ride from the welding method came at a small price.

Without the room needed to expand during extreme heat, the track will buckle and form what looks like a small double S shape. A train, when traveling over these kinks too fast, derails.

One way to combat this phenomenon is to slow down the trains when running through an area where, after close inspection, sun kinks have formed. Sometimes the trains can run over these areas at speeds under 20 miles an hour, which is the speed the National Railway Safety Board recommends on days when the heat is over 92 degrees. This can work some of the time but not always.

Sometimes trains traveling at regulation speeds round a corner and come upon a sun kink. Since it takes a train over half a mile to stop, the engineer has little time to react. All the engineers and ground conductors can do is ease off the throttle, apply brakes slowly and brace. In very few cases, the locomotive which is heavier than the cars it is pulling can make it over this buckled area. But the cars, which are lighter, especially unloaded, cannot and derail.

One way to keep the rails safe and keep trains rolling is the use of a hi-rail truck. These trucks come in various sizes and can run on both the highway and railway. These inspection trucks run down the tracks ahead of trains and visually look for sun kinks. In some cases, the trucks are equipped with inspection equipment that can detect cracks, chips and flaking in the hot rails.

These hi-rail trucks, along with several track replacement and repair vehicles were in Decatur inspecting the track from the TNT truck stop to the south and on past the Simmons feed mill to the north of Decatur. Any defects in the tracks caused by the extreme heat were fixed, making the mainline of the Kansas City Southern safe for not only the crews that control the trains but also the public at large.

Eventually, these crews, about 30 work vehicles, and over 50 workers pressed on to Gentry and Gravette and points along this well-used railway.

Print Headline: Railroad performs local rail repair of track damage

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