The LMS class 2P 2-6-2T Prairie tank steam locomotives were designed by H. G. Ivatt for light mixed traffic duties on branch lines. Construction of the 130 strong class commenced in 1946, only 10 being built by the LMS at Crewe Works. The remainder were built by BR at Crewe (110) and Derby (10) between 1948 and 1952. The LMS-built examples were numbered 1200 to 1209 and renumbered 41200 to 41209 by BR, the remainder followed the sequence up to 41329. BR classification was 2MT.
It was essentially a tank version the Ivatt-designed LMS Class 2F 2-6-0 being introduced at the same time but with shorter range due to the lower coal and water capacity. The locomotives had two outside cylinders and were fitted with Walschaerts valve gear. Slightly larger cylinders were used on later locomotives (41290 onwards) yielding 1,100 lbf extra tractive effort. Fifty of the class (Nos. 41210–20, 41270–89 and 41320–9) were fitted with push-pull gear.
In service, the last thirty crewe-built locomotives were allocated to the Southern Region, the remainder to the London Midland Region. After an initial draughting problem was rectified, they were successful and became the basis for the BR Standard Class 2MT 2-6-2T design.
The class was withdrawn between 1962 and 1967, four have been preserved; Nos. 41241, 41298, 41312, 41313.
LMS Ivatt Class 2P 2-6-2T specification
Length: 38 ft 9½ in (11.82 m)
Gauge: 4 ft 8½ in (1,435 mm)
Driving wheel dia: 5 ft 0 in (1 524mm)
Boiler Pressure: 200 psi (1.38 MPa)
Cylinders: 16 x 24 in (406 x 610mm)
[41290 onwards: 16½ x 24 in (419 x 610mm)]
Loco weight: 63 tons 5 cwt (64.265 tonnes)
Tractive effort: 17,410 lbf (77.444 kN)
[41290 onwards: 18,510 lbf (82.336 kN)]
Last updated 16/11/11