Sectioned original Willans Central Valve engine, 1887, on wooden stand.

Willans engines were often used in early electricity generating stations. This one was built according to Peter Willans’s patent of 1884 and he used it as an experimental engine. It’s full size and sectioned to reveal the novel internal design. A high and a low pressure cylinder are positioned one above the other, both on a shared piston rod, up wthe middle of which a shared valve stem projects to convey the steam from one cylinder to the other. The design was efficeint, capable of high speed operation and quiet, but was ultimately ousted in electricity generation by the Parsons steam turbine.