Steam shovel

A steam shovel is a large steam-powered excavating machine designed for lifting and moving material such as rock and soil. It is the earliest type of power shovel or excavator. Steam shovels played a major role in public works in the 19th and early 20th century, being key to the construction of railroads and the Panama Canal. The development of simpler, cheaper diesel-powered shovels caused steam shovels to fall out of favor in the 1930s. Grimshaw of Boulton & Watt devised the first steam-powered excavator in 1796. In 1833 William Brunton patented another steam-powered excavator which he provided further details on in 1836. The steam shovel was invented by William Otis, who received a patent for his design in 1839. The first machines were known as 'partial-swing', since the boom could not rotate through 360 degrees. They were built on a railway chassis, on which the boiler and movement engines were mounted. The shovel arm and driving engines were mounted at one end of the chassis, which accounts for the limited swing. Bogies with flanged wheels were fitted, and power was taken to the wheels by a chain drive to the axles. Temporary rail tracks were laid by workers where the shovel was expected to work, and repositioned as required. Steam shovels became more popular in the latter half of the nineteenth century. Originally configured with chain hoists, the advent of steel cable in the 1870s allowed for easier rigging to the winches. Later machines were supplied with caterpillar tracks, obviating the need for rails. The full-swing, 360° revolving shovel was developed in England in 1884, and became the preferred format for these machines. Expanding railway networks (in the US and the UK) fostered a demand for steam shovels. The extensive mileage of railways, and corresponding volume of material to be moved, forced the technological leap. As a result, steam shovels became commonplace. American manufacturers included the Marion Steam Shovel Company founded in 1884, the Bucyrus Company and the Erie Shovel Company, now owned by Caterpillar.