The Indian locomotive class WM was a class of 2-6-4T tank locomotives used on 5 ft 6 in (1,676 mm ) broad gauge lines in India from 1942.[ 2] [ 4] [ 5] A total of 70 of them were delivered new, and another four were converted from existing class WV engines.
Indian WM Type and origin Power type Steam Builder Build date 1939, 1951, 1953, 1954 Total produced
Specifications Configuration: • Whyte 2-6-4T • UIC 1′C2′h2t Gauge 5 ft 6 in (1,676 mm )Driver dia.5 ft 7 in (1,702 mm) Axle load 16.25 long tons (16.51 t; 18.20 short tons) Loco weight 96.6 long tons (98.2 t; 108.2 short tons) Fuel type Coal Fuel capacity 6.5 long tons (6.6 t; 7.3 short tons) Water cap. 3,000 imp gal (14,000 L; 3,600 US gal) Firebox: • Grate area 24.6 sq ft (2.29 m2 ) Boiler pressure 210 psi (1.45 MPa) Heating surface 965 sq ft (89.7 m2 ) Superheater: • Type AX pattern (21 A-type elements) • Heating area 230 sq ft (21 m2 ) Cylinders Two, outside Cylinder size 16 in × 28 in (406 mm × 711 mm) Valve gear Walschaerts
[ 2] [ 3]
The ten prototypes of the WM class, the first 30 production units, and the four WV class locomotives that were later converted to WMs, were built by Vulcan Foundry in Newton-le-Willows , Lancashire , England. The remaining 30 WM class engines were built by Robert Stephenson and Hawthorns in North East England .
Table of orders and numbers
Year
Manufacturer
Serial Nos.
Qty
First Nos.
All-India Nos.
Notes
1939
Vulcan
4795-4804
10
2210-2214 (EIR) 2300-2304 (GIPR)
13000–13009
Prototypes
1951
Vulcan
6096-6125
30
9001-9030
13010–13039
1953-1954
Robert Stephenson and Hawthorns
7706-7735
30
9301-9369
13040–13069
1939
Vulcan
4787-4790
4
26954-26957
13070–13073
Converted from WV