The Cast Iron Beams at Kew Bridge Pumping Station — Faithful Friends or Fickle Enemies?

In the nineteenth century, Kew Bridge Pumping Station contained five non-rotative beam engines working on the Cornish cycle. A sixth engine, to the characteristic Bull design without a beam but working on the same principle, was also installed. The oldest of these engines has a cast iron beam manufactured by Boulton, Watt and Company in 1820. The newest beam was cast in 1869. As a result of a failure of an 1820 beam in 1862, the beams of all pumps at Kew Bridge, and in the other London water works, were strengthened by wrought iron bridles and trusses. The 1869 beam was not so fitted when the engine was built, but one side cracked after only seven years’ service. This beam was also strengthened like the others, though the cracked half beam was not replaced. The engines ran in this condition till pumping ceased in 1944. In 1942, the Metropolitan Water Board took the remarkable decision to preserve all the Cornish cycle engines and form a museum. In 1975, the Kew Bridge Engines Trust took over and commenced a restoration programme. Of the four surviving beam engines, three are regularly demonstrated to the public in steam.