The London and North Western Railway Experiment Class was a series of 30 three-cylinder 2-(2-2)-0 compound locomotives designed by Francis Webb for the London and North Western Railway between 1882 and 1884. They were Webb’s first large-scale experiment with a class of express compound locomotives, and the first engine was named accordingly. They were followed by a class of similar, but larger locomotives, that featured larger boilers and smaller driving wheels – the LNWR Dreadnought Class.

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LNWR Experiment Class
No.301 Economist
Type and origin Power type Steam Designer F. W. Webb Builder Crewe Works Serial number 2500, 2625–2628, 2669–2673, 2734–2753 Build date 1882–84 Total produced 30
Specifications Configuration: ​  • Whyte 2-(2-2)-0  • UIC 1AA n3v Gauge 4 ft 8+1⁄2 in (1,435 mm) Leading dia. 3 ft 6 in (1.067 m) Driver dia. 6 ft 6 in (1.981 m) Loco weight 38 long tons (39 t) Fuel type Coal Heating surface 1,083.5 sq ft (100.66 m2) Cylinders Three: two high pressure outside, driving rear wheels; one low pressure inside, driving front drivers High-pressure cylinder 13 in × 24 in (330 mm × 610 mm) Low-pressure cylinder 26 in × 24 in (660 mm × 610 mm) Valve gear Independent Joy valve gear for HP and LP
Career Operators London and North Western Railway Withdrawn 1903–1904 Scrapped 1904–1905 Disposition All scrapped

After Webb's retirement, his successor, George Whale, withdrew the Experiment class locomotives soon after he took up office in 1903.

Accidents and incidents

Main article: Chelford rail accident

• On 22 December 1894, a gust of wind blew a wagon into a rake of wagons at Chelford, Cheshire. They were derailed and fouled the main line. Locomotive No. 520 Express was one of two hauling an express passenger train that collided with the wagons and was derailed. 14 people were killed and 48 were injured.

Locomotives

References

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