South African Class NG G12 2-6-2+2-6-2

Class NG G12 no. 57, c. 1930

Type and origin
Power type	Steam
Designer	Beyer, Peacock and Company
Builder	Société Franco-Belge
Serial number	BP 6365-6366, FB 2506-2507
Model	Class NG G12
Build date	1927
Total produced	2

Specifications
Configuration	2-6-2+2-6-2 (Double Prairie)
Driver	3rd & 4th coupled axles
Gauge	2 ft (610 mm) narrow
Leading dia.	21 in (533 mm)
Coupled dia.	30 in (762 mm)
Trailing dia.	21 in (533 mm)
Wheelbase	40 ft (12,192 mm)
• Engine	12 ft 7 ¹⁄₂ in (3,848 mm) each
• Coupled	5 ft 9 in (1,753 mm) each
Pivot centres	21 ft (6,401 mm)
Length:
• Over couplers	45 ft 10 in (13,970 mm)
Height	10 ft (3,048 mm)
Frame type	Plate
Axle load	3 LT 15 cwt (3,810 kg)
• Leading	3 LT 10 cwt (3,556 kg) front 3 LT 10 cwt (3,556 kg) rear
• Coupled	3 LT 15 cwt (3,810 kg)
• Trailing	3 LT 5 cwt (3,302 kg) front 3 LT 5 cwt (3,302 kg) rear
Adhesive weight	22 LT 10 cwt (22,860 kg)
Loco weight	36 LT (36,580 kg)
Fuel type	Coal
Fuel capacity	2 LT (2.0 t)
Water cap	800 imp gal (3,640 l) front 200 imp gal (909 l) rear
Firebox type	Round-top
• Firegrate area	10.5 sq ft (0.98 m²)
Boiler:
• Pitch	5 ft 3 in (1,600 mm)
• Diameter	3 ft 6 ³⁄₈ in (1,076 mm)
• Tube plates	8 ft 6 in (2,591 mm)
• Small tubes	73: 1 ³⁄₄ in (44 mm)
• Large tubes	10: 5 ¹⁄₄ in (133 mm)
Boiler pressure	180 psi (1,241 kPa)
Safety valve	Pop
Heating surface	423.5 sq ft (39.34 m²)
• Tubes	378.5 sq ft (35.16 m²)
• Firebox	45 sq ft (4.2 m²)
Superheater:
• Heating area	97.5 sq ft (9.06 m²)
Cylinder size	8 ¹⁄₂ in (216 mm) bore 16 in (406 mm) stroke
Valve gear	Walschaerts
Valve type	Piston
Couplers	Bell link-and-pin

Performance figures
Tractive effort	10,400 lbf (46 kN) @ 75%

Career
Operators	South African Railways
Class	Class NG G12
Number in class	2
Numbers	56-57
Delivered	1927
First run	1927
Withdrawn	1952

The South African Railways Class NG G12 2-6-2+2-6-2 of 1927 was an articulated narrow gauge steam locomotive.

In 1927, the South African Railways placed two Class NG G12 Garratt articulated steam locomotives with a 2-6-2+2-6-2 Double Prairie type wheel arrangement in service. They were the smallest Garratt locomotives to see service in South Africa.^[1]^[2]^[3]

Manufacturer

The success of the five Class NG G11 Garratt narrow gauge locomotives, which had been placed in service on the Avontuur line in the Langkloof and the Stuartstown line in Natal between 1919 and 1925, led to the decision by Col F.R. Collins DSO, Chief Mechanical Engineer of the South African Railways (SAR), to acquire a smaller Garratt type for two new light rail narrow gauge branchlines which were completed in 1926. In 1927, orders were placed with Beyer, Peacock and Company for the design and construction of two lightweight narrow gauge Garratt locomotives with a 2-6-2+2-6-2 Double Prairie type wheel arrangement.^[1]^[3]

Beyer, Peacock sub-contracted their construction and the two locomotives were delivered by the Belgian locomotive builders Société Franco-Belge in November 1927. They were therefore allocated separate works numbers by Beyer, Peacock as well as Franco-Belge, and were numbered NG56 and NG57 upon delivery.^[1]^[2]^[4]^[5]

Characteristics

The locomotives were superheated, with outside plate frames, Walschaerts valve gear, inclined cylinders, piston valves and round-topped fireboxes. Designed for light 20 pounds per yard (9.9 kilograms per metre) rail, their lightness of construction made them popular with the fitters who had to maintain them.^[1]^[3]

Classification

The system of grouping narrow gauge locomotives into classes was only adopted by the SAR somewhere between 1928 and 1930 and, at that point, these two locomotives were designated Class NG G12, with the letters "NG" indicating narrow gauge and the "G" prefix to the classification number identifying it as a Garratt locomotive.^[2]^[3]

Service

The Class NG G12 was obtained for use on the new narrow gauge lines from Fort Beaufort to Seymour and from Upington to Kakamas which had been completed in 1926, since it had become obvious that the Class NG6 Lawleys, which had been used during the construction of these lines, would not be able to cope with the expected daily traffic once the lines were in full operation.^[3]

Upon arrival, the two locomotives were first put to work in South West Africa (SWA) for a trial period, after which no. NG56 was assigned to Upington and no. NG57 to Fort Beaufort.^[3]

While they both mostly remained with their assigned depots, they were at times temporarily assigned to narrow gauge branchlines in other areas of the country, to assist with seasonal demands on those branches. In 1940, when the Seymour branch was regauged to Cape gauge, no. NG57 was also assigned to the Kakamas branch. Both remained there until 1949, when the Kakamas line was also widened to Cape Gauge and they were returned to SWA for a brief period. From there, no. NG56 was allocated to Port Shepstone in Natal and no. NG57 to Humewood Road in Port Elizabeth, where they remained until both were withdrawn from service in 1952.^[3]

Both locomotives were subsequently sold to the Rustenburg Platinum Mines, no. NG56 in 1952 and no. NG57 in 1953, where they were renumbered 5 and 6 respectively. They were both scrapped in 1959.^[6]

References

1 2 3 4 Espitalier, T.J.; Day, W.A.J. (1946). The Locomotive in South Africa - A Brief History of Railway Development. Chapter VII - South African Railways (Continued). South African Railways and Harbours Magazine, February 1946. pp. 134-135.
1 2 3 South African Railways and Harbours Narrow Gauge Locomotive Diagram Book, 2'0" Gauge, S.A.R. Mechanical Dept. Drawing Office, Pretoria, 28 November 1932
1 2 3 4 5 6 7 Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 106–107, 110. ISBN 0869772112.
↑ Hamilton, Gavin N., The Garratt Locomotive - Garratt Locomotives produced by Beyer, Peacock, retrieved 10 November 2012
↑ Hamilton, Gavin N., The Garratt Locomotive - Garratt Locomotives from Other Builders, retrieved 10 November 2012
↑ Middleton, John N. (1989). South African Railways Locomotive Allocations - 1989 (4th, 1989 ed.). Auckland Park, South Africa: Railway Preservation Group. p. 20. ISBN 0-620-13670-7

Wikimedia Commons has media related to South African Class NG G12 (2-6-2+2-6-2).

Locomotives of South Africa

Steam

7' ¼" gauge	East London 0-4-0VB Table Bay 0-4-0ST Table Bay 0-4-0T Table Bay 0-4-0WT

4' 8½" gauge	Cape 0-4-0T Blackie Cape 0-4-2 Cape 2-4-0T CGR 0-4-0ST Aid Natal 0-4-0ST Durban Natal 0-4-0WT Natal Natal 4-4-0T Perseverance

3' 6" gauge Tank engines	CGR 0-4-0ST 1873 CGR 0-4-0ST 1874 CGR 0-4-0ST 1881 CGR 0-4-0ST 1881 Coffee Pot CGR 0-6-0ST CGR 0-6-0T CGR 2-6-0ST 1900 CGR 2-6-0ST 1902 CGR 1st Class 0-4-0ST 1875 CGR 1st Class 0-4-0ST 1876 CGR 1st Class 2-6-0ST CGR 1st Class 4-4-0T CGR 2nd Class 4-4-0T CGR 3rd Class 2-6-0T CGR Railmotor CSAR Class C CSAR Class E CSAR Rack 4-6-4RT CSAR Railmotor Durban's Congella Durban's Edward Innes Durban's John Milne Durban's Sir Albert Port Elizabeth 0-4-0ST Kowie Railway 0-6-0T Kowie Railway 4-4-0T Metropolitan & Suburban 4-6-2T NGR 2-6-0T Durban & Pietermaritzburg NGR Class I 2-6-2T NGR Class K 0-4-0ST NGR Class K 0-6-0ST NGR Class K 2-6-0T NZASM 10 Tonner NZASM 13 Tonner NZASM 14 Tonner NZASM 18 Tonner NZASM 19 Tonner NZASM 32 Tonner NZASM 40 Tonner PPR 26 Tonner PPR 35 Tonner Portuguese SAR Class A SAR Class B SAR Class C SAR Class C1 SAR Class C2 SAR Class D SAR Class E SAR Class F SAR Class G SAR Class H SAR Class H1 SAR Class H2 SAR Class J SAR Class K SAR Railmotor SAR Dock 0-4-0ST SAR Dock 0-4-0T SWA 2-8-0T

3' 6" gauge Tender engines	CGR 1st Class 2-6-0 1876 BP CGR 1st Class 2-6-0 1876 Kitson CGR 1st Class 2-6-0 1879 CGR 1st Class 2-6-0 1891 CGR 1st Class 4-4-0 CGR 1st Class 4-4-0TT CGR 2nd Class 2-6-2TT CGR 3rd Class 4-4-0 1883 CGR 3rd Class 4-4-0 1884 CGR 3rd Class 4-4-0 1889 CGR 3rd Class 4-4-0 1898 CGR 3rd Class 4-4-0 1901 CGR 3rd Class 4-4-0 1903 CGR 4th Class 4-4-2 CGR 4th Class 4-6-0TT 1880 CGR 4th Class 4-6-0TT 1882 CGR 4th Class 4-6-0TT 1882 Joy CGR 4th Class 4-6-0TT 1884 CGR 5th Class 4-6-0 1890 CGR 5th Class 4-6-0 1891 NGR Havelock NGR Class I SAR Class Exp 1 SAR Class Exp 2 SAR Class Exp 3 SAR Class Exp 4 SAR Class Exp 5 SAR Class Exp 6 SAR Class S SAR Class S1 SAR Class S2 SAR Class 1 SAR Class 1A SAR Class 1B SAR Class 2 SAR Class 2C SAR Class 3 SAR Class 3A SAR Class 3B SAR Class 4 SAR Class 4A SAR Class 5 SAR Class 5A SAR Class 5B SAR Class 6 SAR Class 6A SAR Class 6B SAR Class 6C SAR Class 6D SAR Class 6E SAR Class 6F SAR Class 6G SAR Class 6H SAR Class 6J SAR Class 6K SAR Class 6L SAR Class 6Y SAR Class 6Z SAR Class 7 SAR Class 7A SAR Class 7B SAR Class 7C SAR Class 7D SAR Class 7E SAR Class 7F SAR Class 8 SAR Class 8A SAR Class 8B SAR Class 8C SAR Class 8D SAR Class 8E SAR Class 8F SAR Class 8R SAR Class 8X SAR Class 8Y SAR Class 8Z SAR Class 9 SAR Class 10 SAR Class 10A SAR Class 10B SAR Class 10C SAR Class 10D SAR Class 11 SAR Class 12 SAR Class 12A SAR Class 12B SAR Class 13 SAR Class 14 SAR Class 14A SAR Class 14B SAR Class 14C 1st SAR Class 14C 2nd SAR Class 14C 3rd SAR Class 14C 4th SAR Class 15 SAR Class 15A SAR Class 15B SAR Class 15C SAR Class 15CA SAR Class 15E SAR Class 15F SAR Class 16 SAR Class 16A SAR Class 16B SAR Class 16C SAR Class 16D SAR Class 16DA 1928 SAR Class 16DA 1930 SAR Class 16E SAR Class 17 SAR Class 18 SAR Class 19 SAR Class 19A SAR Class 19B SAR Class 19C SAR Class 19D SAR Class 20 SAR Class 21 SAR Class 23 SAR Class 24 SAR Class 25 SAR Class 25NC SAR Class 26 SAR Katanga SWA 2-8-0

3' 6" gauge Articulated engines	CGR Fairlie CGR Kitson-Meyer SAR Class FC SAR Class FD SAR Class GA SAR Class GB SAR Class GC SAR Class GCA SAR Class GD SAR Class GDA SAR Class GE SAR Class GEA SAR Class GF SAR Class GG SAR Class GH SAR Class GK SAR Class GL SAR Class GM SAR Class GMA SAR Class GO SAR Class HF SAR Class KM SAR Class MA SAR Class MB SAR Class MC SAR Class MC1 SAR Class MD SAR Class ME SAR Class MF SAR Class MG SAR Class MH SAR Class MJ SAR Class MJ1 SAR Class U

2' 6" gauge	Cape Copper John King & Miner Cape Copper Britannia Cape Copper Caledonia Cape Copper Clara Cape Copper Condenser Cape Copper Scotia Namaqua Copper Pioneer Walvis Bay 2-4-2T Hope

2' & 600mm gauges	ACR Class NG-G16A CGR NG 0-4-0T CGR NG 0-6-0T CGR NG 4-6-2T CGR Type A 2-6-4T CGR Type C 0-4-0T NGR Class N 4-6-2T SAR Dutton SAR NG 0-4-0T SAR Class NG1 SAR Class NG2 SAR Class NG3 SAR Class NG4 SAR Class NG5 SAR Class NG6 SAR Class NG7 SAR Class NG8 SAR Class NG9 SAR Class NG10 SAR Class NG-G11 SAR Class NG-G12 SAR Class NG-G13 SAR Class NG-G14 SAR Class NG15 SAR Class NG-G16 SWA Class Ha SWA Class Hb SWA Class Hc SWA Class Hd SWA Jung SWA Zwillinge

Electric

Amcoal Class E38

Gas-electric

SAR Gas-electric

Diesel

3' 6" gauge Diesel-electric	PRASA Class Afro 4000 SAR Class DS SAR Class DS1 SAR Class 31-000 SAR Class 32-000 SAR Class 32-200 SAR Class 33-000 SAR Class 33-200 SAR Class 33-400 SAR Class 34-000 SAR Class 34-200 SAR Class 34-400 SAR Class 34-500 SAR Class 34-600 SAR Class 34-800 SAR Class 34-900 SAR Class 35-000 SAR Class 35-200 SAR Class 35-400 SAR Class 35-600 TFR Class 35-800 SAR Class 36-000 SAR Class 36-200 SAR Class 37-000 Spoornet Class 39-000 TFR Class 39-200 TFR Class 43-000 TFR Class 44-000

2' gauge Diesel-electric	SAR Class 91-000

3' 6" gauge Diesel-hydraulic	SAR Class 61-000

3' 6" gauge Electro-diesel	Spoornet Class 38-000

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