South African Class Experimental 3 2-8-0

CGR Tandem Compound 2-8-0 1903
South African Class Experimental 3 2-8-0

CGR Tandem Compound no. 839
SAR Class Experimental 3 no. 909

Type and origin
Power type	Steam
Designer	Cape Government Railways (H.M. Beatty)
Builder	American Locomotive Company
Serial number	28638
Model	CGR Tandem Compound
Build date	1903
Total produced	1

Specifications
Configuration:
• Whyte	2-8-0 (Consolidation)
• UIC	1'Dnv4
Driver	3rd coupled axle
Gauge	3 ft 6 in (1,067 mm) Cape gauge
Leading dia.	28+1⁄2 in (724 mm)
Coupled dia.	48 in (1,219 mm)
Tender wheels	33+1⁄2 in (851 mm)
Wheelbase	46 ft 5 in (14,148 mm)
• Engine	22 ft 2 in (6,756 mm)
• Coupled	14 ft 6 in (4,420 mm)
• Tender	14 ft 5 in (4,394 mm)
• Tender bogie	5 ft (1,524 mm)
Wheel spacing (Asymmetrical)	1-2: 4 ft 7 in (1,397 mm) 2-3: 4 ft 3 in (1,295 mm) 3-4: 5 ft 8 in (1,727 mm)
Length:
• Over couplers	53 ft 8+1⁄2 in (16,370 mm)
Height	12 ft 10 in (3,912 mm)
Frame type	Bar
Axle load	14 LT (14,220 kg)
• Leading	7 LT 1 cwt (7,163 kg)
• 1st coupled	14 LT (14,220 kg)
• 2nd coupled	13 LT 2 cwt (13,310 kg)
• 3rd coupled	13 LT 3 cwt (13,360 kg)
• 4th coupled	12 LT 13 cwt (12,850 kg)
Adhesive weight	52.9 LT (53,750 kg)
Loco weight	59 LT 19 cwt (60,910 kg)
Tender weight	34 LT (34,550 kg)
Total weight	93 LT 19 cwt (95,460 kg)
Tender type	2-axle bogies
Fuel type	Coal
Fuel capacity	6 LT (6.1 t)
Water cap.	3,080 imp gal (14,000 L)
Firebox type	Round-top
• Firegrate area	31.3 sq ft (2.91 m²)
Boiler:
• Pitch	7 ft 5 in (2,261 mm)
• Diameter	4 ft 11 in (1,499 mm)
• Tube plates	12 ft 5+5⁄8 in (3,800 mm)
• Small tubes	200: 2 in (51 mm)
Boiler pressure	200 psi (1,379 kPa)
Safety valve	Ramsbottom
Heating surface	1,413 sq ft (131.3 m²)
• Tubes	1,306 sq ft (121.3 m²)
• Firebox	107 sq ft (9.9 m²)
Cylinders	Four
High-pressure cylinder	13 in (330 mm) bore 26 in (660 mm) stroke
Low-pressure cylinder	23 in (584 mm) bore 26 in (660 mm) stroke
Valve gear	Stephenson
Valve type	Piston
Couplers	Johnston link-and-pin

Performance figures
Tractive effort	26,400 lbf (117 kN) @ 75%

Career
Operators	Cape Government Railways South African Railways Transvaal and Natal Collieries
Class	SAR Class Experimental 3
Number in class	1
Numbers	CGR 839, SAR 909
Delivered	1903
First run	1903
Withdrawn	1920

The 2nd and 3rd coupled axles had flangeless wheels

The South African Railways Class Experimental 3 2-8-0 of 1903 was a steam locomotive from the pre-Union era in the Cape of Good Hope.

In 1903, the Cape Government Railways placed a single experimental 2-8-0 Consolidation type tandem compound steam locomotive in service, based on its Schenectady-built 8th Class of 1901. It was similar to the tandem compound locomotive which had been delivered a year earlier, but with a larger firegrate and an increased heating surface. In 1912, when the locomotive was assimilated into the South African Railways, it was renumbered and designated Class Experimental 3.^[1]^[2]^[3]^[4]

Manufacturer

In the first few years of the twentieth century, Cape Government Railways (CGR) Chief Locomotive Superintendent H.M. Beatty experimented with various forms of compound steam locomotives. The second of these experimental locomotives was delivered by the American Locomotive Company (ALCO) in 1903. Like CGR no. 804, the first experimental CGR tandem compound locomotive which had been delivered the year before, it was based on the CGR’s Schenectady-built 8th Class of 1901. It was numbered 839, but it was not classified by the CGR and was simply referred to as the Tandem Compound.^[1]^[2]^[4]

Compound expansion

Compound locomotive

In a compound locomotive, steam is expanded in phases. After being expanded in a high-pressure cylinder and having then lost pressure and given up part of its heat, it is exhausted into a larger-volume low-pressure cylinder for secondary expansion, after which it is exhausted through the smokebox. By comparison, in the more usual arrangement of simple expansion (simplex), steam is expanded just once in any one cylinder before being exhausted through the smokebox.^[5]

Tandem compound

The tandem compound locomotive first appeared on the American Erie Railroad in 1867. In a tandem compound engine, each pair of high- and low-pressure cylinders drove a common crosshead, connecting rod and crank. The high-pressure cylinders were bolted onto the fronts of the low-pressure cylinders, which were usually each cast integrally with one half of the smokebox saddle. The hollow piston valves were mounted on the same valve spindle in a common steam chest, with the high-pressure valves arranged for inside admission and the low-pressure valves for outside admission.^[1]^[4]^[6]

Characteristics

The locomotive was similar to CGR no. 804, the tandem compound which had been delivered to the CGR in 1902 and which was later designated Class Experimental 2, but it had a larger and improved firebox design and an increased heating surface which enhanced its steaming ability. The firegrate area had been increased from 20 to 31.3 square feet (1.858 to 2.908 square metres) and the total heating surface from 1,409.4 to 1,413 square feet (130.938 to 131.272 square metres). However, it suffered from similar mechanical weaknesses as its predecessor.^[2]^[4]

The high-pressure cylinders were 13 inches (330 millimetres) and the low-pressure cylinders 23 inches (584 millimetres) in diameter, with a common stroke of 26 inches (660 millimetres). The steam was admitted to the same side of each piston simultaneously by means of an intricate system of crossed ports in the high-pressure cylinder casting to convey its spent steam to the low-pressure cylinder, from where it was then exhausted after use.^[1]^[4]

Performance

Considerable trouble was experienced with the tandem arrangement, since the piston rod packing between the high- and low-pressure cylinders could not be inspected or serviced without removing the high-pressure cylinder. In addition, as a result of high levels of condensation, the low-pressure cylinders were inefficient since the drain cocks had to be opened frequently enough to detract from the locomotive’s otherwise good performance.^[1]

Service

The locomotive was placed in service on the lower section of the Cape mainline.^[1]^[4]

When the Union of South Africa was established on 31 May 1910, the three Colonial government railways (CGR, Natal Government Railways and Central South African Railways) were united under a single administration to control and administer the railways, ports and harbours of the Union. Although the South African Railways and Harbours came into existence in 1910, the actual classification and renumbering of all the rolling stock of the three constituent railways were only implemented with effect from 1 January 1912.^[3]^[7]

In 1912, the locomotive was designated Class Experimental 3 and renumbered to 909 on the SAR. Unlike the predecessor Class Experimental 2, it was never modified and remained in service as a tandem compound until it was withdrawn and sold to the Transvaal and Natal Collieries in 1920.^[1]^[2]^[3]^[4]^[8]

References

Wikimedia Commons has media related to South African Class Experimental 3 2-8-0.

^ ^a ^b ^c ^d ^e ^f ^g Holland, D.F. (1971). Steam Locomotives of the South African Railways. Vol. 1: 1859–1910 (1st ed.). Newton Abbott, England: David & Charles. pp. 67–68. ISBN 978-0-7153-5382-0.
^ ^a ^b ^c ^d Espitalier, T.J.; Day, W.A.J. (1944). The Locomotive in South Africa - A Brief History of Railway Development. Chapter II - The Cape Government Railways (Continued). South African Railways and Harbours Magazine, March 1944. pp. 169-173.
^ ^a ^b ^c Classification of S.A.R. Engines with Renumbering Lists, issued by the Chief Mechanical Engineer’s Office, Pretoria, January 1912, pp. 9, 12, 15, 36 (Reprinted in April 1987 by SATS Museum, R.3125-6/9/11-1000)
^ ^a ^b ^c ^d ^e ^f ^g Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. p. 82. ISBN 0869772112.
^ van Riemsdijk, John T. (1970). "The Compound locomotive, Parts 1, 2, 3". Transactions of the Newcomen Society (2).
^ van Riemsdijk, John T. (1994). Compound Locomotives: An International Survey. Penryn: Atlantic Books. pp. 36–40. ISBN 0-906899-61-3.
^ The South African Railways - Historical Survey. Editor George Hart, Publisher Bill Hart, Sponsored by Dorbyl Ltd., Published c. 1978, p. 25.
^ Holland, D. F. (1972). Steam Locomotives of the South African Railways. Vol. 2: 1910-1955 (1st ed.). Newton Abbott, England: David & Charles. p. 140. ISBN 978-0-7153-5427-8.

v t e Locomotives of the Cape of Good Hope
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 Cape 0-4-2 Cape 2-4-0T CGR 0-4-0ST Aid
3' 6" gauge	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 2-6-0 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 2-6-0ST CGR 1st Class 4-4-0 CGR 1st Class 4-4-0T CGR 1st Class 4-4-0TT CGR 2nd Class 2-6-2TT CGR 2nd Class 4-4-0T CGR 3rd Class 2-6-0T 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 1890 CGR 5th Class 1891 CGR 6th Class 1893 CGR 6th Class 1896 CGR 6th Class 1897 CGR 6th Class 1898 CGR 6th Class 1900 CGR 6th Class 1901 Baldwin CGR 6th Class 1901 Schenectady CGR 6th Class 1901 Neilson's CGR 6th Class 1902 CGR 6th Class 1904 CGR 6th Class 2-6-2 CGR 6th Class 2-6-4 CGR 7th Class 1892 CGR 7th Class 1896 CGR 7th Class 1902 CGR 8th Class 1901 CGR 8th Class 1902 CGR 8th Class 2-8-0 1903 CGR 8th Class 4-8-0 1903 CGR 8th Class 4-8-0 1903 Exp CGR 8th Class 2-8-0 1904 CGR 8th Class 4-8-0 1904 CGR 9th Class 1903 CGR 9th Class 1906 CGR 10th Class CGR Fairlie CGR Karoo 1903 CGR Karoo 1904 CGR Karoo Compound CGR Kitson-Meyer CGR Mountain 4-8-2 CGR Railmotor CGR Tandem Compound 1902 CGR Tandem Compound 1903 Kowie Railway 0-6-0T Kowie Railway 4-4-0T Metropolitan & Suburban 4-6-2T NCCR 7th Class 1899 NCCR 7th Class 1913 Port Elizabeth 0-4-0ST
2' 6" gauge	Cape Copper 0-6-0T Cape Copper Britannia Cape Copper Caledonia Cape Copper Clara Cape Copper Condenser Cape Copper Scotia Namaqua Copper Pioneer Walvis Bay Hope
2' gauge	CGR Baldwin 2-6-0 CGR NG 0-4-0T CGR NG 0-6-0T CGR NG 4-6-2T CGR Type A CGR Type B CGR Type C
List of South African locomotive classes South African locomotive history

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
Standard 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
Cape 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
Cape 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
Cape 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

Cape 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 TFR Class 45-000
2' gauge Diesel-electric	SAR Class 91-000
Cape gauge Diesel-hydraulic	SAR Class 61-000
Cape gauge Electro-diesel	Spoornet Class 38-000

This page was last edited on 16 August 2023, at 15:58

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