When it comes to railway welding, it can be a very different undertaking from traditional welding, with its own tools and processes involved. With the popularity and functionality of rail services worldwide, it can be important to understand the differences between welding for train tracks and other metal constructs. With this in mind, here is a railway welding 101.
Why is welding used in railways?
Earlier versions of rails were made from iron and typically relied on bolts and riveted joints. These posed several issues when bearing the load of passenger and freight trains, from wriggling loose due to pressure and movement, as well as wear and tear from being exposed to the elements. Welding was quickly introduced after an upgrade to steel rails and sleepers – and with the durability and even the speed and functionality of rail welding equipment, it’s not hard to see why it is the more favorable option over its traditional counterparts.
In the 1950s, rail welding became a standardized practice, incorporating everything from grinders, jacks and ballast shovels to infrastructure machines and equipment with specialized functionalities, such as the rail welding equipment type cr100. As railway tracks are manufactured in lengths of 12.5m to 100m, welding is necessary to form one continuous track, typically to a quarter mile in length, that can then be extended to meet necessity. Rail welding equipment is used to make tracks as long as possible for a low maintenance, smooth and secure ride.
Types of rail welding
There are actually four different types of railway welding, but two are more widely adopted throughout the industry. These include thermite welding and flash butt welding. In both instances, intense heat is used to properly adhere metal and materials together, with flash butt using the rail welding equipment type cr100 and thermite typically requiring specialized welding kits for top functionality. When utilizing thermite, filler will be needed to optimize practices, but flash butt welding will simply function as is to minimize the risk of foreign materials disrupting the overall finish.