Garratt


A Garratt is a type of steam locomotive that is articulated into three parts. Its boiler is mounted on the centre frame, and two steam engine units are mounted on separate frames, one on each end of the boiler.
Articulation permits larger locomotives to negotiate curves and lighter rails that might restrict large rigid-framed locomotives. Garratt locomotives effectively doubled the power of the largest conventional locomotives operating on a railway, thus reducing the need for multiple locomotives and crews.

Advantages of the Garratt concept

The principal benefit of the Garratt design is that the boiler and firebox unit are slung between the two engine units.
As O.S. Nock states, the Garrat type holds several advantages over the Mallet type:
"This was so designed to provide a very large engine unit, to be managed by a single crew, but to spread the dead-weight over many axles and thus avoid excessive loads on the track and under-line bridges, and at the same time retain flexibility of wheelbase to facilitate operation on severely curved sections of line. The Mallet, having driving-wheel units beneath the boiler, retains the limitation in dimensions inherent in the orthodox type of steam locomotive, while the immense length of some of these machines is itself a handicap. Except with oil firing,... one cannot put the cab in front. H.W. Garratt... patented... the idea of having a single large boiler slung on a cradle carried on two entirely separate engine units.... The boiler could be developed to ideal proportions, unfettered by any wheels beneath it. It could be kept short, and of large diameter, which is the best possible form for securing a high rate of evaporation."
Also, because the firebox and ashpan are not restricted in dimensions by running gear, the ashpan can be made to have much larger capacity than that for a normal locomotive. This allows longer continuous runs without need to stop and empty the ashpan, to avoid choking the grate with combustion products. A large firebox and its unrestricted air supply also allowed the Garratt to be run with poor quality fuel, without reducing steaming capacity.
Garratts enjoy an advantage over the Mallet system, because of the geometry of the design. When swinging around curves the boiler and cab unit move inward like a bowstring in the bow of a curve and this reduces the centrifugal force that would overturn a normal locomotive and which in turn permits faster running. The Mallet's forward articulated unit tends to throw out as the locomotive rounds curves. While most Garratts were designed for freight or mixed traffic, there were several passenger Garratt classes. A French-built, Algerian Garratt holds the world speed record for an articulated locomotive, at. Garratts ran equally well in either direction, and many engine crews preferred to run with the cab leading the boiler, particularly in tunnels.
While at the end of the steam locomotive era most conventional steam locomotives had reached their maximum in "critical dimensions", the Garratt still had some way to go, with larger driving wheels, larger boilers and greater output still achievable.

Disadvantages of the Garratt concept

The major disadvantage of a Garratt is that the adhesive weight decreases as the water is used from the front tank and coal from the rear bunker. As the weight on the wheels decreases slipping occurs.

Competitors, look-alikes, and variations on the theme

The Garratt was, obviously, not alone in the field of articulated locomotives. Aside from the well-known Fairlie and Meyer types, the Garratt had contemporary and similarly-designed competition in the form of the Union-Garratt, Modified Fairlie and Golwé. Of these, the closest was the Union-Garratt, a type originally conceived owing to the perceived necessity for a rigid connection between a bunker or tender and a firebox fed by a mechanical stoker.
Though it could be argued that the NZR G class locomotives were Union-Garratts, a more concrete example can be seen in the two South African Railways Union Garratts of classes GH and U.
The Union-Garratt did not enjoy the success of the standard Garratt. It was soon evident that mechanical stokers could function perfectly across the connection between a Garratt's boiler and engine unit, making the rationale for the Union-Garratt obsolete.
The Union-Garratts' extended boiler frames and the position of the bunker and hind water tank upon those frames meant that they suffered from many of the problems which beset the Mallet design; the SAR U and GH classes had much heavier axle-loadings than Garratts of comparable size, weight and power, and the movement of water at the extreme ends of the long main frames generated high wear on the hind pivot between the boiler and engine unit. The Union-Garratt, like the Golwe and Modified Fairlie, was not perpetuated on anything like the scale of the Garratt, and no known examples survive.

Locomotive development

The Garratt articulated locomotive was developed by Herbert William Garratt, a British locomotive engineer who, after a career with British colonial railways, was the New South Wales Railways' Inspecting Engineer in London. Garratt first approached Kitson & Co, but his idea was rejected, perhaps because that company were already committed to the Kitson-Meyer. He then approached Beyer, Peacock and Company, who were only marginally more interested.

The first Garratts

In 1907 Beyer, Peacock & Co. submitted a proposal for a gauge Garratt to the New South Wales Government Railways, which was not proceeded with. The following year a design for a gauge Mallet locomotive was submitted in reply to an enquiry from the Government of Tasmania. This was followed with a submission for a Garratt based on, but a little heavier than, the New South Wales proposal. This proposal was accepted, and two locomotives were built in 1909, which became the K class. The K class had to cope with 99' radius curves and 1 in 25 gradients.
Unlike in Garratt's patent, Tasmanian Railways insisted on a compound arrangement with cylinders facing inwards, in order to reduce the distances between both the main steam pipe and the high-pressure cylinders, and between the high-pressure and low-pressure cylinders.
This made the locomotive unnecessarily complicated and placed the high-pressure cylinders directly underneath the cab, making it uncomfortably hot, especially in summer. The pattern was not repeated on later Garratt designs. Only one more Garratt locomotive, again built by Beyer, Peacock & Co. in 1927, was produced with compound propulsion for the Burma Railways.
Early design and construction difficulties involved the steam-tight flexible connections between the boiler unit and the power units. These were solved by Beyer, Peacock's designers after studying a description of the spherical steam joints used on a Fairlie locomotive built for the Ffestiniog Railway followed by a visit to the FR to observe these locomotives at work.

Darjeeling Himalayan Railway

The third Garratt was built in 1910 for the Darjeeling Himalayan Railway, and given the class letter "D". As with many early Garratt classes, this engine's dimensions and power were designed to be roughly equivalent to those of two of the line's existing engines, although in practice it achieved only a 65% increase in loading.

First main-line class

In 1911 Beyer, Peacock and Company built six Garratts for the Western Australian Government Railways. The M class were followed by the Ms and the Msa class. They also formed the pattern for locos for the Victorian Railways narrow gauge G class, and for Australian Portland Cement.

Final Garratts constructed

Beyer-Peacock built over a thousand Garratts, or Beyer-Garratts. The final Garratts to a Beyer-Peacock design were eight gauge South African Railways Class NG G16 locomotives, built in. The order was placed with Beyer, Peacock and Co., but since the firm was in the process of closing down, it subcontracted the order to the Hunslet Engine Company. Hunslet's South African subsidiary, Hunslet-Taylor, in Germiston, built these locomotives using boilers manufactured by their mother company.
The gauge Southern Fuegian Railway in Argentina procured a new in 1994. Based on Livio Dante Porta's work, it included larger cross section tubing, insulation of the boiler and an improved front end. This vastly improved the economy of this modern steam engine and more than doubled train length. Accordingly, a second Garratt for this railway was built to similar specifications, but with superheating added, in the workshops of Girdlestone Rail in Port Shepstone, South Africa. It was shipped to Argentina in 2006 and entered service in October of that year.

Production list

Garratts around the world

Garratts were used in Africa, Asia, Australia, Europe, and South America. No Garratts were used on North American railroads, the most likely explanation being that American rail companies considered the Garratt's coal and water capacities insufficient for their requirements.

Africa

The Garratt was most widely used in Africa, with large numbers in South Africa, Rhodesia and Algeria and smaller numbers in Angola, Congo, Ghana, Ivory Coast, Kenya, Libya, Madagascar, Mozambique, Nigeria, Senegal, Sierra Leone, Sudan, Uganda, and Zaïre.

Algeria

In Algeria 29 Garratts, constructed between 1936 and 1941 by the Société Franco-Belge de Materiel de Chemins de Fer at Raismes in Northern France, operated until the Algerian independence war caused their withdrawal in 1951. This class, designated 231-132BT, was streamlined and featured Cossart motion gear, mechanical stokers and driving wheels, the largest of any Garratt class. On a test in France, one of these achieved a speed of —a record for any Garratt class.

Angola

All three main railways in Angola used Garratts.
The largest user was the gauge Caminho de Ferro de Benguela. Forty-eight were purchased from Beyer, Peacock between 1926 and 1956. They came in four batches, class 10A ; class 10B in 1930; class 10C in 1954; and class 10D.
The second-largest user was the Caminhos de Ferro de Luanda, who bought six locomotives from Beyer, Peacock in 1949, and six more from Krupp of Germany in 1954.
The other user, was the Caminhos de Ferro de Moçâmedes, who bought six locomotives from Henschel & Son of Germany.

Botswana

Garratts operated on gauge through trains from South Africa to Rhodesia.

Kenya, Tanzania and Uganda

The largest and most powerful steam locomotives to run on the metre gauge were the East African Railways 59 class Garratts, each of them a locomotive with a large grate that delivered a tractive effort of. These thirty-four oil-fired East African Garratts remained in regular service until 1980. Two survive, no. 5918 and 5930. Both have worked since 1980 on tourist excursion trains but are now both out of service and belong to the Nairobi Railway Museum.
The Garratts that ran on the East African Railways, the earlier ones having been inherited from the Kenya Uganda Railways or the Tanganyika Railways, were:
All were built by Beyer-Peacock in Manchester, England, except the 52 class which was built by North British Locomotive Company in Glasgow and some of the 60 class which were built by Société Franco-Belge in France. All were of the wheel arrangement, except the 57 and 58 classes which were.

Mozambique

and Garratts operated in Mozambique, some built as late as 1956.

Rhodesia / Zimbabwe and Zambia

Rhodesia imported 246 gauge Garratts of four different wheel arrangements: s of the 13th, 14th and 14A classes; s of the 15th class, s of the 16th, 16A, and 18th classes; and s of the 20th and 20A classes. Many went to Zambia Railways in 1967 when Rhodesia Railways surrendered the lines in Zambia to its government. Zimbabwe's economic and political situation has extended the life of its Garratts. Five Garratts, including some from the Zimbabwe National Railway Museum, were returned to service in 2004–05 to haul commuter trains. They also perform shunting duties around the city of Bulawayo to this day.

Sierra Leone

On the Sierra Leone Government Railway, this gauge system had Garratts starting in the 1920s and in the middle 1950s purchased 14 Garratts.

South Africa

The most powerful of all Garratts irrespective of gauge were the South African Railways' eight gauge GL class locomotives of 1929–30, which delivered of tractive effort. However, they were all out of service by the late 1960s. There was also a proposal for a quadruplex super Garratt locomotive with a 2-6-6-2+2-6-6-2 wheel arrangement for South African Railways, but this was never built.

Sudan

Sudan operated at least one Garratt.

Asia

Burma

Burma had 43 Garratts, all "metre gauge". Five B class Garratts went to the Burma Railway Company between 1924 and 1927, with seven more built by Krupp of Germany in 1929. They were followed by 31 locomotives transferred from India for War Department service: ten locomotives, class GB ; twelve locomotives of class GC ; and nine locomotives of class GD. A class of four locomotives, the GE class, was built for Burma Railways in 1949, but was diverted to the Assam Railway in India.

Ceylon (now Sri Lanka)

Ceylon had 10 Garratts: an H1 class in 1924, a C1 class in 1927 and eight more C1 class gauge s in 1945.

India

India had 83 Garratts. One gauge was built for the Indian State in 1925. The gauge Bengal Nagpur Railway had 32 Garratts: a pair of HSG class locomotives built in 1925; 16 N class and 10 NM class locomotives built in 1930–31 and four P class locomotives built in 1939.
The metre gauge Assam-Bengal Railway had six T class locomotives built in 1927. They later became the GT class on the Bengal Assam Railway. Three types of Garratt were supplied for war service on the BAR: ten MWGL class locomotives; twelve MWGH locomotives; and 18 MWGX class War Department standard light Garratts. Of these, only nine MWGX stayed in India, with the remainder transferred to Burma. After the war, the four Burma Railways GE class s were diverted to the Assam Railway.

Iran

The Trans-Iranian Railway had 10 Garratts built in 1936.

Mauritius

had three standard gauge Garratts that were built in 1927.

Nepal

The Nepal Government Railway had Garratt locomotives manufactured by Beyer, Peacock and Company in 1932 and 1947.

Siam (Thailand)

acquired 8 German Henschel-built
Garratt during 1929-1937 for heavy freight duties in Pak Chong highland areas. Only one survived and preserved, and currently on display in Kanchanaburi.

Turkey

had just one standard gauge Garratt that was built in 1927.

Australasia

Most states of Australia had sets of Australian Standard Garratt with varying degrees of success during the Second World War and for the decade after.

New South Wales

introduced the AD60 Garratt in 1952, built by Beyer, Peacock. The AD60 weighed 265 tonnes, with a 16-tonne axle loading. As delivered, it developed a tractive effort of ), not as powerful as the South African Railways GMA/M Garratts of 1954, which developed a tractive effort of. Following modifications in 1958 to thirty AD60s, their tractive effort was increased to. These locomotives remained in service until the early 1970s with a replacement "6042" the last withdrawn in February 1973. Oberg wrote he witnessed an AD60 clear a dead 1220-tonne double-headed diesel freight from a 1 in 55 grade without wheel slip. Four AD60's survive today: 6029, 6039, 6040, & 6042.

Queensland

operated thirty Beyer Garratt locomotives. These were mainly based in the Rockhampton area.

Tasmania

Following the success of the K class Garratts on the North East Dundas Tramway, the Tasmanian Government Railways imported Beyer, Peacock Garratts for their main lines, in particular the M class for express passenger work. These were the only eight-cylinder Garratts. The M1 achieved a world speed record of on 30 November 1912. Their 5-foot diameter driving wheels were at the time the largest on any narrow-gauge locomotive in Australia. Their eight cylinders proved a nightmare to maintain, and after several fatal and disastrous derailments in the late 1920s, mainly due to inadequate trackwork, they were withdrawn and scrapped.

Victoria

operated two Beyer Garratts, used on the Crowes and Walhalla narrow gauge railway lines. The two engines were classified as G class, numbered G41 and G42; the latter engine has been restored. It is currently in use at the Puffing Billy Railway near Melbourne. It was not used in public service on that line prior to the preservation era.

New Zealand

Beyer, Peacock built three NZR G class locomotives in 1928, which were too powerful for the system and had complicated valve mechanisms. Unusually, these engines had three cylinders each, on two sets of engine frames, thus creating a six-cylinder Garratt; they were the second and final Garratts to employ this arrangement, the other being the one-off LNER U1. They entered service in 1929. Walschaerts valve gear operated the outside cylinders with the inner third cylinder linked by a Gresley conjugated valve gear. Photos verify the coal bunker was carried on an extension to the boiler frame rather than on the rear engine frame, as with most Garratts. The engines delivered of tractive effort, which was too powerful for the drawbars on the rolling stock. After a few years they were rebuilt as six Pacifics, also unsuccessful, but which saw nearly twenty years of service.
Though no NZR Garratts survived, there are three preserved imported African Garratts in New Zealand. Rhodesia Railways class 15A No.398 of the Flying 15 Trust, Pakakarakiki, class 14A No.509 of Mainline Steam Trust Plimmerton, and South African Railways GMAM class No.4083 at Mercer Auckland with the Mainline Steam Trust awaiting restoration. When it first arrived in NZ in the 1990s, it was steamed and ran in their former Parnell Depot yard. See preservation below.

Europe

Garratts were mainly employed in Great Britain, Russia and Spain, where some five railway companies employed seven classes. These included the 1931 order for Central of Aragon Railway for six "Double Pacific" Garratts for fast passenger service. In addition a Dutch and a Belgian tramway also operated one or more engines based on and built to the Garratt design.

Netherlands

In 1931 the Dutch Limburgsche Tramweg Maatschappij 'Limburg tramway company' ordered a single standard gauge Garratt, numbered LTM 51, from Henschel with builder's number 22063. This design was slightly different in that the coal bunker was located on the boiler frame and both machines only holding the watertanks. More importantly, it was the only Garratt with inside cylinders. The wheel arrangement was C+C. Due to abandonment of the line in 1938 the loc was sold to a metal merchant, who in turn sold it to an engineers' bureau, that sold it in 1941 to Germany. Further whereabouts of this machine are unknown, but it is presumed scrapped.

Spain

Spain had a varied collection of Garratts from most builders; Beyer, Peacock themselves only building a pair of s for Rio Tinto in 1929. The first Garratts in Spain however were four metre gauge s built for the Ferrocarriles Catalanes in 1922 by Sociéte Anonyme St. Leonard of Liége, Belgium. Four more followed in 1925. Also on the metre gauge, the Ferrocarril de la Robla bought two pairs of s, the first from Hanomag of Germany in 1929, the second from Babcock & Wilcox of Bilbao in 1931. The Compania Minera de Sierra Minera also bought a pair of metre gauge s in 1930.
On the broad gauge, the Central of Aragon Railway bought six s from Babcock & Wilcox and six s from Euskalduna of Bilbao, both in 1931. The last Garratts supplied to Spain were ten s for RENFE by Babcock & Wilcox in 1960.

United Kingdom

British usage of Garratts was minimal. A single large Garratt was built in 1925 for banking heavy coal trains on the Woodhead route. 33 Garratts were built for the London, Midland and Scottish Railway between 1927 and 1930, although their undersized axle-boxes made them unreliable and they were withdrawn in the mid-1950s.
Four standard gauge Garratt locomotives were supplied by Beyer Peacock for industrial service in the UK. One survived & is preserved at Bressingham Steam Museum. No. 6841 'William Francis' was built in 1937 for use at Baddesley Colliery.

USSR

Beyer, Peacock constructed the largest steam locomotive built in Europe, a for the USSR, works order number 1176 in 1932. The locomotive had the Russian classification Ya.01. This massive machine was built to the Russian standard gauge and a loading gauge height of. It underwent extensive testing and proved to be very able to operate in extremely low temperatures, due to adequate protection of the external plumbing between boiler and engine units. This may have been the lowest temperature operation of a Garratt type. The locomotive was used for a number of years for coal traffic in the Donbass region, but was never replicated. This decision appears to be a combination of unfamiliar maintenance processes and politics.

North America

No Garratts appeared in North America, although American Locomotive Company became the sole licensee to build Garratts there. Alco was unable to garner sufficient interest from US railroads to produce even a prototype or demonstrator. This reluctance was reportedly based on a concern that tractive effort and factor of adhesion would suffer as the weight of water and fuel over the driving wheels diminished.

United States

In 1975, one Garratt NG class No. 50 formerly of the South African Railways was imported and is used on the gauge Hempstead & Northern Railroad in Hempstead, Texas, who also operate another former South African Railways "Mikado" type No. 18.

South America

Argentina

The British-owned gauge Buenos Aires Great Southern Railway operated twelve Garratt oil-fired locomotives, numbers 4851–4862, built by Beyer, Peacock in 1929. They were used on the Bahía Blanca North Western section, particularly on the Toay line), on the main Bahía Blanca North Western line to General Pico, and between Tres Arroyos and Bahía Blanca. They were withdrawn in the 1950s due to the rapid decline in freight traffic caused by the increasing competition from road transport. The F.C.A.F in Ushuaia uses two gauge Garratts to haul tourists into a National Park with a third under construction.
Other British-owned railway companies in Argentina operated Garratt locomotives built by Beyer, Peacock:
One of the NEA was sold to the Paraguayan Ferrocarril Presidente Don Carlos Antonio Lopez in 1975, and scrapped later in the same year.

Bolivia

Three meter gauge were delivered to the Antofagasta and Bolivia Railway in 1929, followed by six more in 1950.

Brazil

In Brazil, post-1927 the São Paulo Railway operated broad-gauge Garratts that ran passenger trains at 70 m.p.h.

Colombia

In Colombia, one gauge Garratt was purchased by the FC Pacifico in 1924 and two more by the La Dorada in 1937.

Peru

Four standard gauge Garratts were delivered to the Central Railway of Peru from 1929 to 1931.

War locomotives

During World War II, several Garratt designs were built to meet the wartime needs of narrow-gauge railways in Africa, Asia and Australia.
Six Garratts were built for the gauge Sierra Leone Government Railway in 1942, to a design first supplied to that railway in 1926. Five of the older Garratts were converted to a wheel arrangement to increase their tractive effort.
Seventy Garratts were constructed by Beyer, Peacock for the War Department, to three standard designs. A based on the South African Railways GE class was constructed on gauge for West Africa and Rhodesia, while a heavier class of was constructed for East African Railways. A lighter metre-gauge was constructed for India, Burma, and East Africa. This design was particularly successful, and was the basis for several post-war classes.
The Australian Standard Garratt was designed in 1942, for use on gauge railways, in the critical period of World War II following the Japanese bombing of Darwin in 1942, and aerial attacks on other northern Australian centres. It was a locomotive, designed in Australia and constructed by a number of Australian railway workshops. Several design problems with the class emerged, and use of the locomotive encountered resistance from the drivers' union, especially in Queensland. Most were withdrawn at the end of the war, although a number continued to operate successfully in Tasmania.

Preservation

Around 250 Garratts exist today. While many are stored or dumped in various stages of disrepair, more than 100 are preserved in museum collections or on heritage railways. Operating Garratt locomotives, which number about 15, can be found in Europe, Africa, Argentina, the US and Australia. In Spain, a number 282F-0421, nicknamed "Garrafeta", occasionally ran in the Lleida area but no longer. An enormous, number 462F-0401, is under slow cosmetic restoration. Both locomotives are managed by ARMF, a non-profit organisation which also holds the only main line repair workshop for historical railway vehicles on broad gauge network.
A single Hanomag-built narrow gauge example exists in the USA located in Hempstead Texas. It has been made operational again since November 2015.
The first Garratt locomotive, the K class of the North-East Dundas Tramway, has been preserved. After the line closed in 1929 the locomotives were put up for sale. K1 was purchased by Beyer, Peacock in 1947 for their museum. The preserved locomotive has parts from both original engines. When Beyer, Peacock ceased trading, the locomotive was sold to the Ffestiniog Railway, who initially proposed to cut it down to meet their loading gauge. For a number of years it was on loan to the National Railway Museum and was exhibited in York. In 1995 it was removed from York to commence restoration in Birmingham. It was returned to Wales in 2000 where restoration was continued at the Ffestiniog Railway workshops at Boston Lodge. It was fitted with a new boiler and restored to full running order on the Welsh Highland Railway by September 2008. The Welsh Highland Railway owns several former South African SAR NGG 16 Class Garratts, and operates both the first and last Garratts constructed by Beyer, Peacock.. K1 has now been out of use since 2014.
Several Australian Garratts have been restored to operating condition. G 42, formerly used on the narrow gauge lines of the Victorian Railways, works regularly on the Puffing Billy Railway in the Dandenong Ranges outside Melbourne. The Puffing Billy Railway is also rebuilding ex SAR NG/G16 129 which is expected to enter service in 2019. The Queensland Railways removed 1009, its sole remaining gauge Garratt, from an open-air museum and fully restored it to working order. It was out of service by December 2007, awaiting a new boiler. NSWGR AD60 6029 was restored to operating condition in Canberra. As of 2018, 6029 is privately own and is stored and out of Thirlmere, NSW. It is often used by NSW Rail Museum on some mainline excursions and events.
In Kenya, East African Railways 59 class 5918 was maintained in operating condition from 2001 to 2011. Likewise in Zimbabwe 20th class 730 and 740 were held in operating condition until 2004. They have not run since 2004 when 730 was briefly used on Bulawayo commuter services. None are likely to operate again without external funding for major repairs as the only work available for them are excursion trains for foreign tourists and rail enthusiasts.
Unfortunately no New Zealand Railways NZR G class Garratts survived, but three more modern Southern African Garratts have been imported for restoration in New Zealand, with No.509's boiler certified and restoration nearing completion as of 2018.
In December 2007, Zimbabwe class 14A Garratt number 509, overhauled in Bulawayo was offloaded in New Zealand for operational preservation by the Mainline Steam trust. In early 2011 Zimbabwe 15th class 398 was also delivered to New Zealand for restoration to operating condition by Steam Inc.
As of December 2017 there are only two places in the world where one can with reasonable confidence view a Beyer-Garratt in daily operating service. Hwange, Zimbabwe and Ushuaia, Argentina whilst Dinas in North Wales offers the sight of daily operation for about 10 months of the year.
In September 2018, South Eastern Zone of Indian Railways made a successful trial run of a Beyer-Garratt numbered 811 from Kharagpur. A heritage service is planned and scheduled to start from the upcoming festival season.

In fiction

In the twenty-second season of the popular show Thomas & Friends, an EAR 59 class Garratt, named Kwaku, was introduced.