Indian locomotive class SG

SG is the name of a class of Indian steam locomotives used for freight trains. In the designation stands S for Standard, G for Goods. It was by number of built locomotives one of the largest steam locomotive classes built in United Kingdom. The design originated from a BESA standard.

SG
Type and origin Power type Steam Designer British Engineering Standards Association (BESA) Builder Vulcan Foundry, North British Locomotive Company and Robert Stephenson and Hawthorns Build date SG: 1905-13 and SGC3:After 1927 Total produced SG: 486 and SG1: 66 Rebuild date After 1927
Specifications Configuration: ​  • Whyte 0-6-0 Gauge 5 ft 6 in (1,676 mm) Coupled dia. 61.5 in (1.562 m) Wheelbase 15 ft 3 in (4.65 m) Axle load 16 long tons (16 t; 18 short tons) Loco weight 48 long tons (49 t; 54 short tons) Tender weight 39.25 long tons (39.88 t; 43.96 short tons) Fuel type Coal Fuel capacity 7.5 long tons (7.6 t; 8.4 short tons) Water cap. 3,000 imp gal (14,000 L; 3,600 US gal) Firebox: ​  • Grate area 25.3 sq ft (2.35 m2) Boiler 54 in × 11 in (1,372 mm × 279 mm) Boiler pressure 180 psi (1.24 MPa) Heating surface: ​  • Firebox 120 sq ft (11 m2)  • Tubes 1,229.5 sq ft (114.22 m2) Cylinders Two, inside Cylinder size 18.5 in × 26 in (470 mm × 660 mm) Valve gear Rotary Lentz valve gear Valve type Slide valve
Performance figures Maximum speed Freight: 18 mph (29 km/h) Troop trains: 30 mph (48 km/h)
Career Operators Indian Railways, Eastern Bengal Railway, EIR and Oudh and Rohilkhand Railway Locale Eastern Railway zone and Northern Railway zone Disposition Scrapped

History

With the growing demand for locomotives in the British Raj it became for the British industry more and more difficult to deliver the required amount. To speed up delivery the British Engineering Standards Association (BESA) was chartered to develop standard locomotive types. The first BESA report issued in 1903 contained a design recommendation for a 4-4-0 standard passenger locomotive called SP and one for a 0-6-0 standard goods locomotive called SG. Revised versions proposed eight classes of broad gauge locomotives and four classes of meter gauge locomotives for various services. These locomotives were later called BESA locomotives.

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, not only in front of goods trains, but also often in front of 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.

Technical variants

A later built variant with Schmidt superheater was called class SGS, where the designation stands for 'Standard Goods Locomotive, Superheated'. Compared to the saturated steam version, the locomotives received larger cylinders with piston valves and larger boilers, as well as a four-axle tender with bogies.

Locomotives delivered as SG class, which were later converted to superheated locomotives were allocated to the class SGC, where the C stands for 'converted'. The class SGSC, later called SGC2, had round fireboxes instead of the Belpaire firebox of the initial version. SGC3 class locomotives were not only retrofitted with superheaters and but received also a Lentz rotary valve gear.

The 2nd class of standard goods converted locomotives, abbreviated as SGSC and later as SGC2, was another variant distinguished by round fireboxes. Despite its classification, they were used for hauling passenger and mail trains frequently.

There was also a class SG1 with unknown characteristics.

Sub classes

Designation	Number	Year of construction (Rebuilding)	Comments	Divisions
SG	486	1905–1913	Original variant, Belpaire boilers, saturated	NWR EBR
SG1	66
SGC, SGC1		(ab 1927)	Converted SG locomotives with superheater	NWR
SGS	362		Superheater ex works	NWR
SGSC, SGC2			Round top boiler, superheated
SGC3			Superheated, Lentz valve gear	EIR

Preservation

Plinted at Saidpur Works SGC-2 240 made by Vulcan in 1921, 1936 converted to oil, and afterwards used for shunting at Saidpur Works until its withdrawal in 1983.

Working	Class	Number	Location	Built	Zone	Builders	Build No	Name
No	SGC-2		Saidpur Works, Bangladesh	1921	BW	Vulcan Foundry	240

See also

• Indian Railways
• Rail transport in India § History
• Locomotives of India
• Rail transport in India