The Grand Junction 90 inch EngineThe 90" 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.
The original pump plunger of 33 inch diameter was replaced in 1863 with one of 38 inches, this upped the rating of the engine from 5.5 to 7.5 million gallons a day working at 9 1/2 strokes per minute. The rating was later reduced to 6.4 million gallons per day. Today the engine is run at 6 to 6 1/2 strokes per minute and the weight of the plunger has been reduced from 45 to about 32 tons.
The engine is operated on our special Cornish Experience weekends, when all our working Cornish engines are demonstrated. See the Special Events listing for dates this year.
|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|
|Returned to steam||1976|