A steam shovel was an excavating machine powered by steam and regularly used to help move and lift heavy materials like soil and rock. These machines were among the first powered excavators ever created. Although they were once widely used, with the advent of cheaper, easier-to-use diesel shovels, they fell out favor, and many have since been scrapped.
There may be several variations, depending on the make and model; however, many steam shovels were designed the same. All carried a boiler, water tank, and coal bunker, as well as a bucket, steam engines, operator controls, and a house that sat atop the platform to protect the inner workings of the machine. Some steam shovels had regular wheels, while others were fitted with railroad wheels or caterpillar tracks. How the shovel was mounted was another design variation. Early shovels were mounted on flatcars that did not allow the shovel to swing in more than a half-circle motion, while later models were built on turntables.
William Otis invented and patented the steam shovel in 1839. Some of the earliest partial-swing models consisted of movement engines and boilers mounted atop a railway chassis and fitted with flanged wheels. Early steam shovel use required temporary tracks to be laid in order to move the machine where it was needed to work. As the demand for this equipment rose, caterpillar tracks were installed, which made it easier to move this machine from place to place.
Although the steam shovel became a common and necessary piece of machinery while railway networks were being built, by the 1930s it began to fall out of favor. This was mainly due to the fact that the diesel-powered shovel became available and offered a more inexpensive, simpler alternative. By the 1950s, some of the most well-known steam shovel developers discontinued their production of these machines, and many of the existing models have since been scrapped.
Despite the fact that the steam shovel is no longer used, some feel that these machines serve as an important part of history. Some models have been preserved and placed in industrial museums and private collections. The Ruston Proctor Steam Navvy No 306 is a good example of preservation efforts. This machine was rescued from a water-filled pit in England, restored, and placed in front of a well-known museum.