GWR 1400 Class

GWR 4800 class (later 1400 class)

4866, one of the four preserved 1400 Class 0-4-2T

Type and origin Power type Steam Builder GWR Swindon Works Order number Lots 279, 287, 288 Build date 1932–1936 Total produced 75

Specifications Configuration 0-4-2T UIC class B1 nt Gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge Driver dia. 5 ft 2 in (1.575 m) Trailing dia. 3 ft 8 in (1.118 m) Wheelbase 15 ft 6 in (4.72 m) Length 29 ft 11 in (9.12 m) Width 8 ft 7 in (2.616 m) Height 12 ft 6 1⁄4 in (3.816 m) Axle load 13 long tons 18 cwt (31,100 lb or 14.1 t) (15.6 short tons) full Adhesive weight 27 long tons 8 cwt (61,400 lb or 27.8 t) (30.7 short tons) full Loco weight 41 long tons 6 cwt (92,500 lb or 42 t) (46.3 short tons) full Fuel type Coal Fuel capacity 2 long tons 13 cwt (5,900 lb or 2.7 t) (3.0 short tons) Water cap 800 imp gal (3,600 l; 960 US gal) Firebox:  • Firegrate area 12.8 sq ft (1.19 m2) Boiler pressure 165 psi (1.14 MPa) Heating surface:  • Tubes 869.8 sq ft (80.81 m2)  • Firebox 83.2 sq ft (7.73 m2) Superheater None Cylinders Two, inside Cylinder size 16 in × 24 in (406 mm × 610 mm) Valve gear Stephenson Valve type Slide valves Train heating Steam Train brakes Vacuum

Performance figures Tractive effort 13,900 lbf (62 kN)

Career Operators GWR » BR Class 4800, later 1400 Power class GWR: Unclassified, BR: 1P Numbers 4800–4874, later 1400–1474 Axle load class GWR: Unclassified Withdrawn 1956–1965 Preserved 1420, 1442, 1450, 1466 Disposition Four preserved, remainder scrapped

The GWR 1400 Class is a class of steam locomotive designed by the Great Western Railway for branch line passenger work. It was originally classified as the 4800 Class when introduced in 1932, and renumbered in 1946.

Although credited to Collett, the design dated back to 1868 with the introduction of the George Armstrong 517 class.

Like the 48xx/14xx, the 517 Class was a lightweight loco for branchline work; it was built at Wolverhampton Works between 1868 and 1885.

In this period evolutionary changes included:

Later gradual changes included: Belpaire fireboxes, boilers rated at 165 psi (1.14 MPa) as opposed to 150 psi (1.0 MPa), full cabs, extended bunkers and the progressive conversion of short wheelbase locos to 15 ft 0 in (4.57 m) or 15 ft 6 in (4.72 m). From 1924 onwards, several were converted to run with an , and in this configuration were the direct ancestors of the 48xx class.

In this form, the updated 517's were but a small step away from the 48xx. The wheelbase was still 15 ft 6 in (4.72 m), the boiler still rated at only 165 psi (1.14 MPa), and the wheels 5 ft 2 in (1,575 mm) and 3 ft 8 in (1,118 mm). New was the Collett-style cab and bunker and the boiler nominally to a new design. A three bar crosshead was added to the motion. This was a 1924 innovation introduced with the GWR 5600 Class and also seen in the 1930s-built 5400, 6400 and 7400 classes of pannier tanks.

The 4800 Class was designed as a more modern version of the 517 Class, which were by then beginning to show their relative age. The first locomotive, No 4800, was built by Swindon Works and entered service in 1932, with a further seventy-four engines of this type following up to 1936. During this period, Swindon also built twenty 5800 Class engines, which were broadly similar but which were not fitted with autotrain equipment or the Swindon top feed as later fitted to a number of 4800 class engines.

The 4800 Class locomotives retained their original numbers until the GWR decided to experimentally convert twelve 2800 Class 2-8-0s for oil-firing. It was decided that the converted engines would be reclassified as the 4800 Class and so the 75 tank locomotives already carrying this designation were reclassified as the 1400 Class with running numbers 1400-1474. The engines did not revert to their original classification after the experiment ended in 1948.