Midland Railway 483 Class

Midland Railway 483 Class
Rebuilt Midland Johnson 2P 4-4-0 No. 40542 at Chesterfield 1959
Type and origin Power type Steam Designer Samuel W. Johnson Build date Midland locos built 1882-1901 S&DJ locos built 1914-1921
Specifications Configuration: ​  • Whyte 4-4-0 Gauge 4 ft 8+1⁄2 in (1,435 mm) standard gauge Driver dia. Original, 6 ft 6.5 in (1.994 m) Rebuilt, 7 ft 0.5 in (2.146 m) Loco weight 53 tons 7 cwt Fuel type Coal Boiler pressure 160 psi Cylinders Two inside Cylinder size Original, 18 in × 26 in (460 mm × 660 mm) Rebuilt, 20.5 in × 26 in (520 mm × 660 mm)
Performance figures Tractive effort Original, 15,960 lb Rebuilt, 17,585 lb
Career Power class LMS 2P

The Midland Railway 483 Class 4-4-0 was a class of steam locomotive designed by Samuel W. Johnson for passenger work on the Midland Railway. This design formed the basis for the later LMS Class 2P 4-4-0. The London, Midland and Scottish Railway (LMS) seems to have inherited three batches of these locomotives and some of them passed into British Railways (BR) ownership in 1948.

Numbering

• BR numbers 40332-40397 (17 locomotives) originally built 1882-1891, some rebuilt from 1910 onwards
• BR numbers 40400-40562 (143 locomotives) originally built 1891-1901, all rebuilt between 1912 and 1923
• BR numbers 40322-40326 (5 locomotives) built for Somerset and Dorset Joint Railway 1914-1921 and taken into LMS stock in 1930

Note: two of the above number series contain gaps so the totals do not tally.

Rebuilding

On rebuilding, the Stephenson valve gear was retained but the following changes were made:

• 18 in × 26 in (460 mm × 660 mm) cylinders with slide valves were replaced by 20.5 in × 26 in (520 mm × 660 mm) cylinders with piston valves
• 6 ft 6.5 in (1.994 m) driving wheels were replaced by 7 ft 0.5 in (2.146 m) driving wheels
• a superheater was fitted

External links

• Rail UK database, Older locos
• Rail UK database, Newer locos
• Rail UK database, Somerset and Dorset locos