The cast iron beam at the top, known as a ‘bob’, is a staggering 10 metres in length and weighs in at over 52 tonnes. The total weight of the engine is over 125 tonnes.
What did it do?
As mines got deeper, they quickly filled up with water. The engine's job was to pump water from the bottom of the mine shaft at a depth of approximately 510 metres (1700ft) to keep the tunnels safe and clear for the workers.
At its height, the Cornish tin-mining industry had around 600 steam engines working to pump out mines all over the county. In the Camborne area there were many mines close together, which meant that every engine had to work continuously. If one stopped pumping, often its neighbour would start to flood.
When Taylor’s engine was stopped after the Second World War, the neighbouring South Crofty mine, which was still working, started to flood. As a result, the engine was run for a further nine years, to keep South Crofty clear. It finally stopped working on 11 September 1954 when electric pumps were installed.
How did it work?
The engine lifted the massive pump rod up and down the shaft, pumping water from the bottom. Gravity pulled the rod down and was then balanced by heavy boxes on the surface and below. A model of this mechanism can be seen in the reception area.
The engine raised the water out of the shaft in stages, through a series of valves, which act like one-way trap doors. Each stroke pumped 410 litres (90 gallons) of water up through the first valve; this in turn forced the water that had already passed the first valve up and through the next valve. This kept on repeating until the water reached an underground water course (or adit) where the water then flowed into the Red River valley and to the East Pool processing plant in Tolvaddon before eventually going out to sea.