English: Twyford Pumping Station - pumps below the steam engine. Hathorn, Davey & Co Ltd of Leeds built this inverted vertical triple expansion steam engine in 1913 as works No. 6579. The Corliss valve cylinders are 16", 28" & 46" bores by 36" stroke. The engine ran at 25 rpm on superheated steam at 150 psi and developed c150 horsepower. The engine drove well pumps via a pitman and opposed bell cranks and transfer pumps from the main piston crossheads by side-rods. This is the view below the engine showing the plunger type transfer pumps. A plunger is seen above and right of centre with the four rods passing up to the engine's crosshead above. The lower edge of one flywheel is seen at the top. On the left is one of the three vertical assemblies containing pump valves with an air vessel above. This also supports the front of the engine on the floor above. The large pipe passing to the right is the discharge with a non-return valve having a bypass pipe and valve round it. The spring-loaded valve is a pressure relief valve. This is part of the engine that is not normally seen by the public and I was down here with permission.