LMS Beyer-Garratt Locomotives in Great_Britain

Class 4997 (Locobase 671)

Data from Wiener (1930). See also "Articulated Locomotives-Their Evolution and Advantages", Railway Wonders of the World, 30 August 1935 at [], last accessed 5 December 2020. Works numbers were 6325-6327 in 1927, 6648-6677 (10 Batch 1164, 20 Batch 1165).

Thirty-three of these Garratts (4967-4996) were delivered in 1930) pulled coal traffic in trains of 1,500 tons on the 126-mile run between South Yorkshire and London on the London, Midland, and Scottish. Unlike many of the toy-like sub-standard-gauge Garratts, these engines were substantial engines in every respect, especially in British service.

Compared to a North American Mallet, however, they were still relatively small. A medium-sized 2-8-2 North American Mikado matched their power dimensions. RW's report noted their postive qualities: "Thirty-three of these valuable engines are now at work, and they daily haul 1,450-ton coal trains at overall speeds of 21 mph (34 kph) for distances of more than a hundred miles (161 kph). With a hundred empty wagons they can attain 50 mph (81 kph).

Tufnell (1986) takes some of the gloss off these brutes by commenting that they had a hand-firing rate of 110 lb per mile (31 kg/km) and frequently snatched the couplers out of the 12-ton (14.4 short tons)coal cars they pulled. Also a rotating coal bunker, designed to reduce coal dust in the cab, often jammed. Still, they ran into the 1950s, being retired between 1953-1958.

Note: Glover (1967) states that the boiler contained 202 small tubes and 36 superheater flues and measured 75" in diameter. The A/S ratio for such an arrangement would be 23.25%. I go with Wiener (1930) because his book specifically deals with articulated locomotives in a systematic and comprehensive way.