2-6-2+2-6-2

Locomotive wheel arrangement
2-6-2+2-6-2
Diagram of one small leading wheel, three large driving wheels joined by a coupling rod, two small trailing wheels, three large driving wheels joined by a coupling rod, and one small leading wheel
South African Railways Class GB
Equivalent classifications
UIC class1C1+1C1, 1'C1'+1'C1'
French class131+131
Turkish class35+35
Swiss class3/5+3/5, 6/10 from 1920s
Russian class1-3-1+1-3-1
First known tank engine version
First use1912
CountryAustralia
LocomotiveL class
RailwayTasmanian Government Railways
DesignerBeyer, Peacock and Company
BuilderBeyer, Peacock and Company
Evolved from2-6-0+0-6-2

Under the Whyte notation for the classification of steam locomotives by wheel arrangement, 2-6-2+2-6-2 is an articulated locomotive using a pair of 2-6-2 power units back to back, with the boiler and cab suspended between them. The 2-6-2 wheel arrangement has a single pair of leading wheels in a leading truck, followed by three coupled pairs of driving wheels and a pair of trailing wheels in a trailing truck.

Overview

The 2-6-2+2-6-2 wheel arrangement was used on Garratt, Modified Fairlie and Union Garratt locomotives.

Garratt locomotives

The 2-6-2+2-6-2 was the second most numerous Garratt wheel arrangement to be built, with altogether 238 examples constructed by Beyer, Peacock and Company (BP) and its licensees. Most of them were built to 3 ft 6 in (1,067 mm) Cape gauge, 1,000 mm (3 ft 3+3⁄8 in) metre gauge and the 2 ft 6 in (762 mm) or 2 ft (610 mm) narrow gauges. None were built to the 4 ft 8+1⁄2 in (1,435 mm) standard gauge, but several were built to 5 ft 3 in (1,600 mm) and 5 ft 6 in (1,676 mm) gauges.[1][2]

The first examples of the type were two 3 ft 6 in (1,067 mm) 2-6-2+2-6-2 L class Garratts built for the Tasmanian Government Railways in 1912. This wheel arrangement also included the final Garratts to be built by BP, seven 2 ft (610 mm) South African Class NG G16 locomotives in 1958.[1]

2-6-2+2-6-2 Garratt production list – All manufacturers[1][2]
Gauge Railway Class Works no. Units Year Builder
2 ft South African Railways NG G16 6919-6926 8 1939 Beyer, Peacock
2 ft South African Railways NG G16 7426-7432 7 1951 Beyer, Peacock
2 ft South African Railways NG G16 7862-7868 7 1958 Beyer, Peacock
2 ft South African Railways NG G12 2506-2507 2 1927 Franco-Belge, Belgium
2 ft South African Railways NG G14 10747 1 1930 Hanomag
2 ft South African Railways NG G13 10549-10551 3 1927 Hanomag
2 ft South African Railways NG G13 10598-10599 2 1928 Hanomag
2 ft South African Railways NG G13 10629-10635 7 1928 Hanomag
2 ft South African Railways NG G16 3894-3901 8 1967-68 Hunslet-Taylor
2 ft South African Railways NG G16 3265-3268 4 1936 John Cockerill
2 ft 6 in Nepal Government Railway 6736 1 1932 Beyer, Peacock
2 ft 6 in Nepal Government Railway 7243 1 1947 Beyer, Peacock
2 ft 6 in Sierra Leone Government Railway 6297-6299 3 1926 Beyer, Peacock
2 ft 6 in Sierra Leone Government Railway 6497-6498 2 1928 Beyer, Peacock
2 ft 6 in Sierra Leone Government Railway 6578-6579 2 1929 Beyer, Peacock
2 ft 6 in Sierra Leone Government Railway 7045-7048 4 1942 Beyer, Peacock
2 ft 6 in Sierra Leone Government Railway 7049-7050 2 1943 Beyer, Peacock
1,000 mm Great Western of Brazil 1024-1025 2 1929 Armstrong Whitworth
1,000 mm La Robla Railway, Spain 421-422 2 1931 Babcock & Wilcox, Spain
1,000 mm Assam-Bengal Railway, India T 6385-6389 5 1927 Beyer, Peacock
1,000 mm Transandine Railway, Argentina E12 6543-6546 4 1930 Beyer, Peacock
1,000 mm Minera de Sierra Minera, Spain 189-190 2 1930 Euskalduna, Spain
1,000 mm La Robla Railway, Spain 10646-10647 2 1929 Hanomag
1,000 mm C.G. de F. Catalanes, Spain 1960-1963 4 1922 St. Leonard, Belgium
1,000 mm C.G. de F. Catalanes, Spain 2035-2038 4 1925 St. Leonard, Belgium
3 ft 6 in South African Railways GB 5942 1 1921 Beyer, Peacock
3 ft 6 in Natal Navigation Collieries, South Africa 6206 1 1925 Beyer, Peacock
3 ft 6 in South African Railways GG 6232 1 1925 Beyer, Peacock
3 ft 6 in Dundee Coal & Coke Ltd, South Africa 6353 1 1927 Beyer, Peacock
3 ft 6 in Trans Zambezia, Moçambique/Nyasaland E 6380 1 1930 Beyer, Peacock
3 ft 6 in Consolidated Main Reef Mine, South Africa 6780 1 1935 Beyer, Peacock
3 ft 6 in Tasmanian Government Railways L 5525-5526 2 1912 Beyer, Peacock
3 ft 6 in New Cape Central Railway, South Africa G 6135-6136 2 1923 Beyer, Peacock
3 ft 6 in Trans Zambezia, Moçambique/Nyasaland E 6178-6179 2 1924 Beyer, Peacock
3 ft 6 in South African Railways GB 6181-6186 6 1924 Beyer, Peacock
3 ft 6 in South African Railways GC 6187-6192 6 1924 Beyer, Peacock
3 ft 6 in South African Railways GD 6263-6266 4 1925 Beyer, Peacock
3 ft 6 in Rhodesia Railways 13 6269-6280 12 1926 Beyer, Peacock
3 ft 6 in South African Railways GD 6281-6287 7 1925 Beyer, Peacock
3 ft 6 in South African Railways GD 6288-6290 3 1926 Beyer, Peacock
3 ft 6 in Rhodesia Railways 14 6510-6515 6 1929 Beyer, Peacock
3 ft 6 in Guayaquil & Quito Railway, Ecuador 6527-6529 3 1929 Beyer, Peacock
3 ft 6 in Rio Tinto Railway, Spain 6560-6561 2 1928 Beyer, Peacock
3 ft 6 in Rhodesia Railways 14 6616-6625 10 1930 Beyer, Peacock
3 ft 6 in Rhodesia Railways 14A 7581-7592 12 1952 Beyer, Peacock
3 ft 6 in Rhodesia Railways 14A 7599-7604 6 1953 Beyer, Peacock
3 ft 6 in South African Railways GCA 1043-1068 26 1928 Krupp
3 ft 6 in South African Railways GCA 970-982 13 1927 Krupp
3 ft 6 in South African Railways GDA 3115-3119 5 1929 Linke-Hofmann
5 ft 6 in North Western Railway, India GAS 6203 1 1925 Beyer, Peacock
5 ft 6 in Ceylon Government Railway C1 6410 1 1927 Beyer, Peacock
5 ft 6 in São Paulo Railway, Brazil R1 6367-6372 6 1927 Beyer, Peacock
5 ft 6 in Ceylon Government Railway C1A 7160-7167 8 1945 Beyer, Peacock

Modified Fairlie locomotives

The Modified Fairlie was first introduced in South Africa, when the South African Railways (SAR) experimented with a modified type of Fairlie locomotive in order to compare the concept to that of the Garratt locomotive in terms of actual performance and maintenance requirements. In essence, the Modified Fairlie was an adaptation of the Kitson-Meyer concept. It was similar in appearance to a Garratt, but with the boiler, cab, coal and water bunkers all mounted on a single rigid frame which pivoted on the engine units, with the pivot centers located approximately at the centre of the rigid wheelbase of each engine unit. In the Garratt design, by comparison, the coal and water bunkers are mounted directly on the engine units and swivel with them, while the boiler, firebox and cab are mounted on a rigid frame which is suspended between the two engine units.[3][4][5][6]

Union Garratt locomotives

The Union Garratt was a hybrid locomotive, part Garratt and part Modified Fairlie, designed and built for the SAR by Maffei in Munich, Germany. The front end of the locomotive was of a typical Garratt arrangement, with a water tank mounted on the front engine unit’s frame, while the rear end was constructed in the Modified Fairlie fashion, with the coal bunker mounted on a rigid extension of the locomotive’s main frame and with the pivoting rear engine unit positioned beneath the coal bunker.[3][4]

Usage

Sierra Leone

Sierra Leone Government Railway Garratt locomotive no. 50 of 1926

The Sierra Leone Government Railway acquired altogether 27 2 ft 6 in (762 mm) gauge 2-6-2+2-6-2 Garratt locomotives from BP between 1926 and 1956. Seven were delivered in 1926, 1928 and 1929. Six more followed in 1942 and 1943 and fourteen more in 1955 and 1956.[1]

Another two were delivered to the Sierra Leone Development Corporation in 1937, also from BP.[1]

South Africa

The largest user of the type was the South African Railways (SAR) who operated 132 locomotives of this wheel arrangement, spread over fifteen classes. Of these, ten classes were Cape gauge (83 locomotives) and five classes were 2 ft (610 mm) narrow gauge (49 locomotives). Two of the narrow gauge locomotives were later rebuilt to improve coal combustion and reclassified.[1][2]

Cape gauge

The 3 ft 6 in (1,067 mm) Cape gauge 2-6-2+2-6-2 locomotives of the SAR entered service between 1921 and 1929.

SAR Class GB no. 2166
  • In 1921, a single experimental Class GB Garratt entered service, followed by six more in 1924, designed and built by BP. They were superheated, with Belpaire fireboxes, plate frames and Walschaerts valve gear.[1][3][4][6]
  • In 1923, the New Cape Central Railway (NCCR) placed two Garratts in service, built by BP in 1922 to the design of the Class GB. They were also superheated, with plate frames and Walschaerts valve gear, but heavier and with larger cylinders. In 1925, when the NCCR was amalgamated into the SAR, the two Garratts were designated Class GK.[1][4][7][8]
  • In 1924, a single experimental Class FC Modified Fairlie entered service, designed and built by North British Locomotive Company (NBL). It had Walschaerts valve gear, a plate frame and was superheated.[3][4][9]
  • In 1924 and 1925, six Class GC Garratts entered branchline service. They were built by BP in 1924 and were superheated, with Belpaire fireboxes, plate frames and Walschaerts valve gear.[1][3][4][7]
SAR Class GG no. 2290
  • In 1925, a single Class GG Garratt entered service. It was a development of the Class GB with large 57 inches (1,450 millimetres) driving wheels for fast passenger service on mainline duties. Built by BP, it was superheated, with a plate frame, a Belpaire firebox and Walschaerts valve gear. The Class GG was the only Garratt on the SAR to be intended primarily for passenger working.[1][3][4][7]
  • In 1925 and 1926, fourteen Class GD Garratts entered branchline service. Marginally larger and more powerful than their predecessor Class GC and with a higher axle loading, they were built by BP. They were superheated and had plate frames, Belpaire fireboxes and Walschaerts valve gear.[1][3][4][7]
  • In 1926, four Class FD Modified Fairlies entered service, designed and built by NBL in 1925. They had Walschaerts valve gear, plate frames and were superheated.[3][4][9]
SAR Class U Union Garratt
  • In 1927, ten Class U Union Garratt locomotives were placed in service. The locomotives, designed and built by Maffei, were superheated and had Walschaerts valve gear and bar frames.[2][3][4][7]
  • In 1927 and 1928, 39 Class GCA Garratts entered branchline service. They were built by Friedrich Krupp AG of Essen in Germany to the same specifications as the Class GC, but with bar frames, round-topped fireboxes and with water tanks and built-up coal bunkers of a different shape. Like the Class GC, they were superheated and had Walschaerts valve gear.[2][3][4][6][7]
  • In 1929, five Class GDA Garratts entered branchline service. They were built by Linke-Hofmann Werke AG in Breslau, Germany, to the same specifications as the Class GD, also superheated and with Walschaerts valve gear, but with bar frames, differently shaped coal and water bunkers and round-topped fireboxes.[2][3][4][7]

Narrow gauge

The South African 2 ft (610 mm) narrow gauge 2-6-2+2-6-2 locomotives entered service between 1927 and 1968. Two were rebuilt in 1989 and 1990 and reclassified.

SAR Class NG G12
  • In 1927, two Class NG G12 Garratts entered service, the smallest Garratts to see service in South Africa. Ordered from BP in 1927, their construction was sub-contracted to Belgian locomotive builders Société Franco-Belge. They were superheated, with outside plate frames, Walschaerts valve gear and round-topped fireboxes.[1][2][4][10]
  • In 1927 and 1928, twelve Class NG G13 Garratts entered service on the Langkloof and Harding narrow gauge lines. Designed and built by Hannoversche Maschinenbau AG (Hanomag) in consultation with the SAR, the type was to become the standard narrow gauge Garratt in South Africa for the next forty years. They were superheated, with outside bar frames and round-topped fireboxes, and with an extremely compact arrangement of Walschaerts valve gear. The leading wheels were arranged as conventional pony trucks, while the inner trailing wheels were built to the Gölsdorf system which allowed the axle some lateral movement.[1][2][4][6][7]
  • In 1931, a single light Class NG G14 Garratt entered service. Built by Hanomag in 1930, it was similar to but slightly larger than the Class NG G12, also superheated but with larger bore cylinders, an outside bar frame and a round-topped firebox.[2][4][7]
SAR Class NG G16 no. 113
  • Between 1937 and 1968, 34 Class NG G16 Garratts were placed in service, spread over five orders from three manufacturers. It was almost identical to the Class NG G13, but with all leading and trailing wheels fitted with roller bearing axle boxes and arranged as pony trucks. Société Anonyme John Cockerill of Belgium delivered four in 1937. Another 22 were built by BP in 1939, 1951 and 1958, the last seven being the last steam locomotives to be built by BP. The final eight locomotives in 1968 were the last new steam locomotives to be ordered by the SAR and were built by Hunslet-Taylor in Germiston, Transvaal.[1][2][4][6][7]
  • In 1989 and 1990, two Class NG G16 Garratts were rebuilt by the Alfred County Railway to incorporate a gas producing combustion system (GPCS) and were reclassified to Class NG G16A. The rebuilding was done by mechanical engineer Phil Girdlestone, using technology similar to that used by mechanical engineer David Wardale in the creation of the Class 26 Red Devil in 1980.[4][11][12]

Southern Rhodesia

With altogether 46 locomotives of this wheel arrangement, all built by BP, the second largest user of the 2-6-2+2-6-2 Garratt was the Rhodesia Railways (RR) of Southern Rhodesia, which also operated in Northern Rhodesia and Mozambique.[1]

In 1926, twelve 13th Class 2-6-2+2-6-2 Garratts were ordered by the Beira and Mashonaland and Rhodesia Railways (BMR). They were based at Umtali in Southern Rhodesia to work the difficult section of the Beira line into Mozambique between Umtali and Vila Machado. In 1930, these locomotives were replaced on this duty by 14th Class Garratts, after which they were mainly based at Salisbury in Southern Rhodesia until their withdrawal from service.[13][14]

The 13th class also operated in Northern Rhodesia, with a couple being allocated for short periods to Livingstone. Two locomotives were also hired out to the Rhokana Corporation copper mine at Nkana in Kitwe, Northern Rhodesia. These two locomotives were eventually purchased by the mine, one coming to a tragic end in 1950 when it struck a lorry loaded with explosives at a level crossing, causing many deaths since the train carried miners going on shift in an open wagon.[13][14]

RR 14th class no 500

In 1929, the success of the 13th Class led to an improved version being ordered by RR, which the BMR had now become. While of the same wheel arrangement and similar power output as the 13th class locomotives, these sixteen had, amongst other improvements, bar instead of plate frames and round-topped instead of Belpaire fireboxes. These were designated the 14th Class and all of them were initially allocated to Umtali to replace the 13th class Garratts on the line to Vila Machado in Mozambique. From 1939, some of the class were transferred for branchline work in Southern Rhodesia at the Salisbury, Bulawayo and Gwelo depots.[13][14]

NRZ 14A class no 515

In October 1949, the Beira line in Mozambique was taken over by the state-owned Caminhos de Ferro de Moçambique (CFM). At the same time, the CFM purchased a number of locomotives from RR, including eight 14th Class Garratts, which continued to work on the Beira line from the new depot at Gondola in Mozambique.[13][14]

In 1950, RR ordered a modernised version of the 14th Class for branchline work in Southern Rhodesia. There were eighteen of them and they were designated the 14A Class. From 1979, they were refurbished for shunting work, receiving roller bearings on the driving and coupled axles and, in many cases, larger water tanks and coal bunkers. By 2012 this class, now on the roster of the National Railways of Zimbabwe, still saw occasional service on Bulawayo shunt duties.[13][14]

References

Wikimedia Commons has media related to 2-6-2+2-6-2 locomotives.
  1. ^ a b c d e f g h i j k l m n o Hamilton, Gavin N., The Garratt Locomotive - Garratt Locomotives produced by Beyer, Peacock, retrieved 10 November 2012
  2. ^ a b c d e f g h i j Hamilton, Gavin N., The Garratt Locomotive - Garratt Locomotives from Other Builders, retrieved 10 November 2012
  3. ^ a b c d e f g h i j k Holland, D. F. (1972). Steam Locomotives of the South African Railways. Vol. 2: 1910-1955 (1st ed.). Newton Abbott, England: David & Charles. pp. 41–45, 47–54, 56, 61–62. ISBN 978-0-7153-5427-8.
  4. ^ a b c d e f g h i j k l m n o p q Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 10–11, 78–79, 89–94, 96–97, 106–107, 109–110. ISBN 0869772112.
  5. ^ The Fairlie locomotive
  6. ^ a b c d e Durrant, AE (1989). Twilight of South African Steam (1st ed.). Newton Abbott: David & Charles. pp. 25, 31, 110, 124, 126–127. ISBN 0715386387.
  7. ^ a b c d e f g h i j South African Railways and Harbours Locomotive Diagram Book, 2’0” & 3’6” Gauge Steam Locomotives, 15 August 1941, as amended
  8. ^ Holland, D.F. (1971). Steam Locomotives of the South African Railways. Vol. 1: 1859–1910 (1st ed.). Newton Abbott, England: David & Charles. pp. 79–80. ISBN 978-0-7153-5382-0.
  9. ^ a b North British Locomotive Company works list, compiled by Austrian locomotive historian Bernhard Schmeiser
  10. ^ South African Railways and Harbours Narrow Gauge Locomotive Diagram Book, 2’0” Gauge, S.A.R. Mechanical Dept. Drawing Office, Pretoria, 28 November 1932
  11. ^ Information supplied by Phil Girdlestone
  12. ^ "Alfred County Railway 2-6-2+2-6-2 NG G16A Garratts 141 & 155". martynbane.co.uk. Retrieved 2009-07-10.
  13. ^ a b c d e Durrant, A.E. (1997). The Smoke that Thunders, (1st ed.). Harare: African Publishing Group. ISBN 1-77901-134-2.
  14. ^ a b c d e Pattison, R.G. (2005). Thundering Smoke, (1st ed.). Ilminster, Somerset: Sable Publishing House. ISBN 0-9549488-1-5.
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Single engine typesDivided drive and
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