Humphrey pump, King George V Pumping Station
Introduction
The photograph on this page of Humphrey pump, King George V Pumping Station by Chris Allen as part of the Geograph project.
The Geograph project started in 2005 with the aim of publishing, organising and preserving representative images for every square kilometre of Great Britain, Ireland and the Isle of Man.
There are currently over 7.5m images from over 14,400 individuals and you can help contribute to the project by visiting https://www.geograph.org.uk

Image: © Chris Allen Taken: 22 Nov 1985
The only other examples are at Cobdogla in Australia and at least one is workable. These are large producer gas driven engines with the water acting as a piston. Amazingly enough these beasts actually worked.