There are over a billion miles of railroads laid all around the world. It’s a long and circuitous network of pathways that lead to various different cities and towns. However, these miles of tracks aren’t manufactured all at once but are instead built as smaller units and then joined later. The joining process can either take the bolting approach or the newer welding approach.
While bolting is the traditional method of joining railroad units, welding is preferable on high-speed routes. Such welded units together form what is known as continuous welded rail (CWR) or ribbon rails.
Besides the act of laying down tracks, welding is also useful in repairing broken tracks. This particular application is especially important as it helps prevent snags and even derailment. Here’s a video clip that shows how railway crews weld damaged tracks to rejoin them.
Popular types of welding and their uses
Flash butt welding in railroad construction
Flash butt welding is a popular method for making ribbon rails. This type of railroad measures several kilometers and is comparatively sturdier and low-maintenance. Since a train route with ribbon rails has fewer joints, it allows for the faster and smoother passage of trains.
The process of flash butt welding involves placing two railroad units, head-to-head, such that their ends are in contact. Then, a strong electric current surges through them, causing a huge amount of heat to build up on the track ends due to resistance. This heat causes visible sparks or flashes. The pair of track units, which have malleable ends at this temperature point, are pressed together to finish the task.
Thermite welding in railroad maintenance
When it comes to re-joining broken tracks, thermite welding is a go-to option for the railway crew. It is a popular technique of railroad maintenance that reduces the chances of train mishaps. Thermite welding is a quick, convenient, and economical way of repairing tracks.
Thermite welding or exothermic welding revolves around employing a chemical reaction using aluminum powder and metal oxide at a certain high temperature. This leads to the formation of liquid metal that the repairman passes into a mold. Inside it, the hot liquid metal melts the ends of a pair of track units and causes them to connect.
Have you ever seen the railroad welding process in person? Tell us your thoughts in the comments below. Also, while we’re on this topic, make sure to check out these railroad repairing machines.