GWR 850 Class
Class 850 of the Great Western Railway was an extensive class of small 0-6-0 saddle tank locomotives designed by George Armstrong and built at the Wolverhampton Works of the Great Western Railway between 1874 and 1895. Aptly described as the GWR equivalent of the LBS&CR "Terrier" Class of William Stroudley, their wide availability and lively performance gave them long lives, and eventually they were replaced from 1949 by what were in essence very similar locomotives, the short-lived 1600 Class of Frederick Hawksworth, which in the headlong abandonment of steam outlived them by a mere seven years or so.
The 850 Class consisted of 170 locomotives and was built in 14 lots:
- Nos. 850-861 (Lot T, 1874)
- Nos. 862-873 (Lot V, 1874-5)
- Nos. 987-998 (Lot X, 1875-6)
- Nos. 1216-1227 (Lot Y, 1876-7)
- Nos. 1901-1912 (Lot J2, 1881-82)
- Nos. 1913-1924 (Lot L2, 1882)
- Nos. 1925-1936 (Lot O2, 1883-4)
- Nos. 1937-1948 (Lot Q2, 1886-7)
- Nos. 1949-1960 (Lot R2, 1888)
- Nos. 1961-1972 (Lot T2, 1889-90)
- Nos. 1973-1984 (Lot V2, 1890-91)
- Nos. 1985-1996 (Lot X2, 1891)
- Nos. 1997-2008 (Lot Y2, 1891-92)
- Nos. 2009-2020 (Lot Z2, 1894-5)
In addition Nos. 93 and 94 were supplied in 1875 and 1877 as renewals of the original Gooch locomotives of 1860. The locomotives from No. 1216 onwards were originally described as a separate class, the 1901 Class.
The original 36 locomotives had their domes on the firebox, while the domes of the rest were on the middle of the boiler. The two classes became more uniform on rebuilding. All had full-length saddle-tanks; the wheels were 4'0" diameter, the wheelbase was 13'8", and cylinders 15" x 24". They had inside frames. Pannier tanks were fitted from 1910, as rebuilding with Belpaire boilers took place, and from 1924 larger coal bunkers were fitted to many of the class.
The engines were widely spread over the GWR network. They were useful for shunting in dock areas, as at Plymouth, Bristol, Llanelly, and Birkenhead, which was their last stronghold; in 1881-2 four went new to the Cornwall Minerals Railway. In 1906 and 1913 four were sold into industrial service, followed by four more in 1939. Up to 1927 the class were used on empty stock work at Paddington. 43 would pass into British Railways ownership and were classified "2F"; ten were painted in BR unlined black, and the last examples survived as late as 1958, the last Armstrong engines in service.
- le Fleming 1958, pp. E43-E50.
- le Fleming, H.M. (1958). The Locomotives of the Great Western Railway, part five: Six-coupled Tank Engines. Kenilworth: RCTS.