GWR 2021 Class

GWR 2021 Class
No. 2080 at Berkeley Road station 1948
Type and origin Power type Steam Designer George Armstrong Builder Wolverhampton, GWR Order number Lots: D3, F3, G3, H3, J3, K3, L3, M3 Serial number Works Nos: 625–764 Build date 1897 (1897) – 1905 Total produced 140
Specifications Configuration: ​  • Whyte 0-6-0ST Gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge Driver dia. 4 ft 1 1⁄2 in (1.257 m) Wheelbase 7 ft 4 in (2.24 m) + 7 ft 4 in (2.24 m), total 14 ft 8 in (4.47 m) Length 30 ft 1 in (9.17 m) over buffers Width 8 ft 2 in (2.49 m) Height 11 ft 10 3⁄8 in (3.62 m) Frame type Type: Inside Length: 25 ft 8 in (7.82 m) Width:7 ft 7 in (2.31 m) Axle load 13 long tons 12+3/4 cwt (29,200 lb or 13.3 t) (13.9 t; 15.3 short tons) full Loco weight 40 long tons 13+3/4 cwt (89,700 lb or 40.7 t) (41.3 t; 45.6 short tons) full Fuel type Coal Water cap 1,000 imp gal (4,500 l; 1,200 US gal) Firebox:  • Firegrate area 14.5 sq ft (1.35 m2) Boiler Barrel: 10 ft 0 in (3.05 m) Outside diameter: 3 ft 9 7⁄8 in (1.165 m) and 3 ft 9 in (1.14 m) Pitch: 6 ft 0 3⁄4 in (1.848 m) Boiler pressure 150 lbf/in2 (1.03 MPa) Heating surface 1,018.75 sq ft (94.645 m2)  • Tubes 926.25 sq ft (86.051 m2)  • Firebox 92.5 sq ft (8.59 m2) Cylinders Two, inside Cylinder size Diameter: 16 1⁄2 in (419 mm) Stroke: 24 in (610 mm) Loco brake Steam
Performance figures Tractive effort 16,830 lbf (74.86 kN)
Career Operators GWR Class 2021 Number in class 140 Numbers 2021–2160 Withdrawn 1944–57 Disposition All scrapped

The GWR 2021 Class was a class of 140 0-6-0 saddle tank steam locomotives. They were built at the Wolverhampton railway works of the Great Western Railway between 1897 and 1905. 1897 was the very year of George Armstrong's retirement, so it is uncertain if the design should be attributed to him or to his superior at Swindon, William Dean.

In fact the 2021s were simple enlargements of the Armstrong-designed 850 class of 1874. The changes were fundamentally confined to a longer wheelbase to permit fitting of a larger firebox.

The class was built in eight batches:

Rebuilding with Belpaire fireboxes commenced in the early years of the Churchward era. Unsuccessful attempts to form a saddle tank around the firebox directly led to the switch to pannier tanks. The rebuilding of the whole class took place over many years. In their final form, with or without fully enclosed cabs, 110 of them survived into British Railways ownership, the last of them being retired in 1956. They were superseded by the short-lived GWR 1600 Class, nominally a Hawksworth design, but in reality a straightforward update of the then 75-year-old design, with new boiler, bigger cab and bunker.