Capital role: This Vickers Armstrong engine was built for Tower Bridge
Deepest rural Norfolk is, perhaps, the last place you would expect to find monthly ‘steam ups’ of industrial engines representing much of their era. Yet Forncett Industrial Steam Museum, about 10 miles south of Norwich, has a Vickers Armstrong 147hp Horizontal Cross Compound engine from London’s Tower Bridge.
Built in Newcastle upon Tyne in 1941, it was a back-up to the two original 1894 engines should a bomb destroy them and otherwise stop vital supply ships berthing upstream in the Pool of London. However, it was only 6ft away from the original pair, separated by a brick wall. The three engines charged the six accumulators for the hydraulic system used to raise and lower the 1,000-ton bascules of Tower Bridge.
At one end of the scale, Forncett museum has a readily portable, model-sized engine that may have been used in a workshop, right up to the 85-ton Worthington Simpson 600hp Inverted Vertical Triple Expansion engine, built in Newark, Nottinghamshire. The latter, although completed in 1937, was only installed in Dover in 1954 and is the last waterworks steam pumping engine ever installed in Britain. It is the only one for which the museum has a complete set of drawings, donated by the chief draughtsman.
In contrast, the museum has the second-oldest working Corliss Rotary Valve Gear engine in the world, which powered a Nottingham lace factory. The valve, invented in the US in the mid-19th century, enabled an engine to run at constant speed under varying load and so produce a consistently-spaced weave in fabrics.
Green giant: The 85-ton, 600hp Worthington Simpson engine
The museum celebrates the days before electric motors, when the industrial steam engine was the unseen power behind all our major industries, the drinking water supply, our transport infrastructure and every sort of machine that needed to be driven.
Steam from a solid-fuelled Cochran vertical boiler powers all the machines, including a Marshall engine that drives the shafts, belts and pulleys in the Victorian workshop that boasts a 72-inch lathe, one of the longest in the region.
Overlooking a quiet pond with reeds and willows in the valley of the River Tas that flows, a few miles further north, past the old Roman port city of Venta Icenorum, is the Hopwas Beam Engine Gallery. A popular venue for weddings, rallies and meetings, it is home to Spruce, one of two 50hp Gimson single-cylinder, condensing, rotative water pumping beam engines. It was used to pump water until 1962 and was donated to the Forncett museum by the South Staffordshire Water Works Co in 1987 from its Hopwas pumping station near Tamworth.
The museum also has an Easton and Anderson 65hp A-frame Woolf compound waterworks beam engine. Both beam engines have the parallelogram mechanism that James Watt invented to replace chains, and that doubled the power of such engines as the upstroke of a piston also became a power stroke.
5 things to see
1. Victorian workshop: A Marshall steam engine powering line shafts, belts and pulleys.
2. Sleaford Maltings: 200hp Tandem Compound engine.
3. Last Steam Pump: 600hp, 85-ton Triple Expansion Vertical engine, built in 1937.
4. Lace Factory: Early example of a Corliss Valve Gear engine.
5. Hopwas Beam Engine Gallery: 50hp Gimson pumping engine from Staffordshire.
Rowan Francis
For more details, see: www.forncettsteammuseum.co.uk
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