LMS 3-Cylindered Stanier 2-6-4T

LMS Stanier Class 4P 3-cylinder 2-6-4T

42504 at Stratford, November 1961

Type and origin Power type Steam Designer William Stanier Builder LMS Derby Works Build date 1934 Total produced 37

Specifications Configuration 2-6-4T UIC class 1′C2′ h3tb Gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge Leading dia. 3 ft 3 1⁄2 in (1.003 m) Driver dia. 5 ft 9 in (1.753 m) Trailing dia. 3 ft 3 1⁄2 in (1.003 m) Wheelbase 38 ft 6 in (11.73 m) Length 47 ft 2 3⁄4 in (14.40 m) Width 8 ft 11 1⁄2 in (2.73 m) Height 12 ft 10 1⁄2 in (3.92 m) Loco weight 92.25 long tons (93.73 t; 103.32 short tons) Fuel type Coal Fuel capacity 3.50 long tons (3.56 t; 3.92 short tons) Water cap 2,000 imp gal (9,100 l; 2,400 US gal) Firebox:  • Firegrate area 25 sq ft (2.3 m2) Boiler LMS type 4C Boiler pressure 200 lbf/in2 (1.4 MPa) Heating surface:  • Tubes and flues 1,011 sq ft (93.9 m2)  • Firebox 137 sq ft (12.7 m2) Superheater: ​  • Heating area 160 to 154 sq ft (14.9 to 14.3 m2) Cylinders Three Cylinder size 16 in × 26 in (406 mm × 660 mm)

Performance figures Tractive effort 24,598 lbf (109.42 kN)

Career Operators London, Midland and Scottish Railway → British Railways Power class LMS: 4P BR: 4MT Numbers LMS 2500–2536 BR 42500–42536 Withdrawn 1960–1962 Disposition One preserved, remainder scrapped

LMS Stanier Class 4P 3-Cylinder 2-6-4T is a class of steam locomotive designed for work over the London, Tilbury and Southend Railway. All 37 were built in 1934 at Derby Works and were numbered 2500–2536. The third cylinder was provided to allow increased acceleration between the many stops on the L.T.&S.R. line. From 1935 the LMS switched to constructing a very similar, simpler, 2-cylinder design. In 1941 two of the class had just been released from overhaul from Derby Works at the same time as a Jubilee class 4-6-0 failed in Derby station. The two tanks took over and got the train into St Pancras only 25 minutes late.

No. 2500 was the first of the 37 express passenger tank locomotives designed specifically for the London Tilbury and Southend line of the London Midland & Scottish railway (LMS) as they were too powerful for mixed-traffic work. It was built in 1934 at LMS Crewe works.

The class were withdrawn from 1960 to 1962.

No. 2500 has survived and is on display at the National Railway Museum's Shildon Locomotion Museum. It is the sole survivor of this class and is painted in LMS lined black livery.