The Indian locomotive class SG is a class of Indian steam locomotives used for goods trains. Its class designation, SG, stands for Standard Goods. It was, by number of locomotives built, one of the largest steam locomotive classes built in the United Kingdom. It was one of the BESA locomotives developed by the British Engineering Standards Committee, later called the British Engineering Standards Association (BESA).
History
With the growing demand for locomotives in the British Raj, it became increasingly difficult for British locomotive manufacturers to fulfill that need. To alleviate that problem, the British Engineering Standards Association (BESA) was comissioned to develop standard locomotive types. The first BESA report issued in 1903 recommended designs for a 4-4-0 standard passenger locomotive classified as SP and one for an 0-6-0 standard goods locomotive classified as SG. Later, revised editions of the BESA reports proposed eight classes of broad gauge locomotives and four classes of meter gauge locomotives for various services; these locomotives were later called BESA locomotives.[2]
The SG class was used by the North Western State Railway (NWR), the Eastern Bengal Railway (EBR), the East Indian Railway (EIR) and the Oudh and Rohilkhand Railway (ORR) in India, hauling both goods and passenger trains. They could haul 1450 tons of freight with a speed of 18 mph (29 km/h). Some locomotives were in service in India until the early 1980s and in Pakistan until the 1990s.[3]
Design variants
A later variant designed with a Schmidt superheater was classified SGS (Standard Goods, Superheated). These locomotives received larger cylinders with piston valves and larger boilers, as well as a four-axle tender with bogies, as compared to their earlier designs which used saturated steam.[3]
SG class locomotives retrofitted with superheaters were classified as SGC (Standard Goods, Converted). The SGSC class, later called SGC2, had round fireboxes instead of the Belpaire firebox of the original design. SGC3 class locomotives were retrofitted with superheaters and were fitted with the Lentz rotary valve gear.[3] Despite their classifications, they frequently hauled passenger and mail trains.[3]
A design variant classified as SG1 existed with unknown design characteristics.[3]
Subclasses
Designation
Number
Year of construction
(Rebuilding)
Comments
Divisions
SG
486
1905–1913
Original design, Belpaire fireboxes, saturated steam
NWR
EBR
SG1
66
Unknown design characteristics
SGC, SGC1
(around 1927)
SGs retrofitted with superheaters
NWR
SGS
362
SGs delivered with superheaters
NWR
SGSC, SGC2
Round firebox, superheated
SGC3
Superheated, Lentz valve gear
EIR
Preservation
Plinthed at Saidpur Works: SGC2 number 240 made by Vulcan in 1921, 1936 converted to oil, and afterwards used for shunting at Saidpur Works until its withdrawal in 1983.
