The Grand Junction 90 inch engine

The 90 inch Engine is the largest working beam engine in the world. It was built in 1846 by Sandys, Carne & Vivian of Copperhouse Foundry, Hayle, Cornwall and was the first engine built in Cornwall specially for waterworks duty.

Kew Bridge Works in London started supplying water in 1838. The steam engines work for more than 100 years and were retired from service in 1944, although two were kept on standby until 1958.
The Metropolitan Water Board, who now owned the works, decided to keep the engines as a museum only removing one of the Boulton & Watt engines to provide exhibition space. The present Museum Trust took over the site, and one by one restored the engines to working order, starting with the Boulton & Watt engine in 1975 and lastly with the Bull engine in 2008.

Date of manufacture 1846
Cylinder Diameter 90 inches (2.28 metres)
Stroke 132 inches (3.35 metres)
Weight of Beam 32 tons (32.4 tonnes)
Water output per stroke 472 Gallons (2142 litres)
Water output per 24 hours 6.4 M Gallons (29.1 M litres)
Strokes per minute 6 - 6 1/2
Last worked 1943
Returned to steam 1976

Sound recordist: Ben Minto/Soundkids