Steam Hammer

A steam hammer is a power hammer driven by steam, used to shape forgings. It consists of a hammer-like piston located within a cylinder. The hammer is raised by the pressure of steam injected into the lower part of a cylinder and falls down with a force by removing the steam. Usually, the hammer is made to fall faster by injecting steam into the upper part of the cylinder. Steam hammers that fall by their own weight are called steam drop hammers. Steam hammers vary greatly in weight from 45 kilograms to 90 metric tons.

The steam hammer was invented around 1839 by the Scot, James Nasmyth, in Manchester, England and produced in his Patricroft foundry which he built adjacent to the (then new) Liverpool and Manchester Railway and the Bridgewater Canal. From the first, Nasmyth's steam hammer could vary the force of the blow within a very wide range. He was fond of showing how he could break an egg placed in a wineglass without breaking the glass, which was followed by a blow that shook the building.

An original Nasmyth hammer stands facing his foundry buildings (now a 'business park'). A larger Nasmyth & Wilson steam hammer stands in the campus of the University of Bolton.

The intended first use of the steam hammer lay in forging the paddle shaft of the SS Great Britain. However, the paddle technology was replaced with the screw propeller, and implementation of the hammer was left to the Schneider, Creusot foundry in Le Creusot, France.

The steam hammer was one of many machine tools invented around this time which allowed for large scale industrialisation and the use of machines to build machines. Using the same principles of operation, Nasmyth also developed a revolutionary steam powered pile-driving machine. At its first use at Devonport, a dramatic contest was carried out. His engine drove a pile in four and half minutes compared to the twelve hours that the conventional method required.