The oldest triple-expansion, double-acting, inverted, condensing steam engine still operating in the UK.
Originally installed to draw raw water from the River Wye and deliver it to the treatment works on Broomy Hill behind the pumping station.
Clean water descended from the treatment works to the high-pressure pumps, below the centre cylinder of the engine, for return to the water-tower tank.
Three steam cylinders of increasing bore.
Steam-heated cylinder jackets and valve chests.
Meyer valve gear on the high pressure cylinder.
Original steam pressure: 120 psi (8 atmospheres).
Current steam pressure: 50 psi (3.3 atmospheres).
Speed of rotation: 26 rpm.
Pumping capacity: 4.5 Mlitres (1 million gallons) per 12 hours in situ.