The Mallet locomotive is a type of
articulated steam railway locomotive, invented by the Swiss engineer
Anatole Mallet
Jules Theodore Anatole Mallet (23 May 1837 – 10 October 1919) was a Swiss mechanical engineer, who was the inventor of the first successful compound system for a railway steam locomotive, patented in 1874. He is known for having invented three i ...
(1837–1919).
The front of the locomotive articulated on a
bogie
A bogie ( ) (in some senses called a truck in North American English) is a chassis or framework that carries a wheelset, attached to a vehicle—a modular subassembly of wheels and axles. Bogies take various forms in various modes of transp ...
. The
compound steam system fed steam at boiler pressure to high-pressure cylinders driving the rear set of driving wheels (rigidly connected to the boiler). The exhaust steam from these cylinders was fed into a low-pressure receiver and was then sent to low-pressure cylinders that powered the driving wheels on the swiveling bogie towards the front of locomotive.
Compounding
Steam under pressure is converted into mechanical energy more efficiently if it is used in a
compound engine
A compound engine is an engine that has more than one stage for recovering energy from the same working fluid, with the exhaust from the first stage passing through the second stage, and in some cases then on to another subsequent stage or even st ...
; in such an engine steam from a boiler is used in high-pressure (HP) cylinders and then under reduced pressure in a second set of cylinders. The lower-pressure steam occupies a larger volume and the low-pressure (LP) cylinders are larger than the high-pressure cylinders.
A third stage (triple expansion) may be employed. Compounding was proposed by the British engineer
Jonathan Hornblower
Jonathan Hornblower (5 July 1753 – 23 February 1815) was an English pioneer of steam power.
Personal life
The son of Jonathan Hornblower the Elder and the brother of Jabez Carter Hornblower, two fellow pioneers, the young Hornblower wa ...
in 1781.
The American engineer W. S. Hudson patented a system of compounding for railway locomotives in 1873
[US Patent 136729, ''Improvement in Locomotives'', March 11, 1873] in which he proposed an intermediate receiver surrounded by hot gas from the fire, so that the low-pressure steam is partly
superheated
A superheater is a device used to convert saturated steam or wet steam into superheated steam or dry steam. Superheated steam is used in steam turbines for electricity generation, steam engines, and in processes such as steam reforming. There are ...
.
Mallet proposed cross-compounding in which a conventional steam locomotive configuration would have one high-pressure cylinder and one low-pressure cylinder.
[Mallet, A, ''On the Compounding of Locomotive Engines'', Proceedings of the Institution of Mechanical Engineers, London, June 1879, page 328, quoted in ''The Steam Engine: A Treatise on Steam Engines and Boilers'', Clark, D K, Blackie and Co, London] He patented the system in 1874, and in 1876 the first locomotive to the patent was built, an for the
Bayonne and Biarritz Railway
Bayonne (; eu, Baiona ; oc, label= Gascon, Baiona ; es, Bayona) is a city in Southwestern France near the Spanish border. It is a commune and one of two subprefectures in the Pyrénées-Atlantiques department, in the Nouvelle-Aquitaine re ...
. Several others followed for railways in mainland Europe.
[''Loco Profile 6: The Mallets'', Reed, Brian, Profile Publications Limited, Windsor, undated]
The
London and North Western Railway
The London and North Western Railway (LNWR, L&NWR) was a British railway company between 1846 and 1922. In the late 19th century, the L&NWR was the largest joint stock company in the United Kingdom.
In 1923, it became a constituent of the Lo ...
locomotive engineer
F W Webb adopted the idea and converted some existing locomotives in 1879, followed by
de Glehn
Alfred George de Glehn (15 September 1848 – 8 June 1936) was a notable English-born French designer of steam locomotives and an engineer with the Société Alsacienne de Constructions Mécaniques (SACM). His steam engines of the 1890s combined el ...
and others in the 1880s and several American engineers in the 1890s which included some vertical boiler railcar applications.
[
]
Articulation
Mallet found typical main line railways were unwilling to adopt his ideas. In 1884, he proposed compounding combined with articulation; on lightly engineered secondary lines this could give greater power to locomotives whose axle load and size were limited. His patent 162876 in France specified four cylinders, two large and two small, with one pair of cylinders acting on two or three fixed axles, and the other pair acting on axles mounted in a swivelling truck.
The weight of the front part of the boiler was to be supported on an arc-shaped radial bearing. The truck could therefore turn into a curve and move to some extent laterally. Typically the support bearing was placed beneath the smokebox
A smokebox is one of the major basic parts of a steam locomotive exhaust system. Smoke and hot gases pass from the firebox through tubes where they pass heat to the surrounding water in the boiler. The smoke then enters the smokebox, and is e ...
, hollowed and with a sliding seal to provide a route for exhaust steam from the low-pressure cylinders to discharge through a blastpipe The blastpipe is part of the exhaust system of a steam locomotive that discharges exhaust steam from the cylinders into the smokebox beneath the chimney in order to increase the draught through the fire.
History
The primacy of discovery of th ...
within the smoke box.
Mallet considered that the major advantage of this arrangement was that it enabled the cylinders on the truck to be fed with low-pressure steam: the high-pressure cylinders were on the fixed main frame and only low-pressure steam needed to be carried through movable pipes to the swivelling truck.
The Mallet concept
This then was what became understood as a "Mallet" locomotive: an articulated locomotive in which the rear set of driving wheels were fixed in the main frame of the locomotive; an articulated truck carrying a second set of driving wheels; and compounding in which the high-pressure cylinders drove the axles on the main frame and the articulated axles were driven by low-pressure steam.
Mallet asserted that the advantages of his concept were:
* all the locomotive weight would be adhesive, yet there would be great flexibility of the locomotive as a vehicle;
* the difficulties with Meyer Meyer may refer to:
People
*Meyer (surname), listing people so named
* Meyer (name), a list of people and fictional characters with the name
Companies
* Meyer Burger, a Swiss mechanical engineering company
* Meyer Corporation
* Meyer Sound Labo ...
, Fairlie and other then-existing articulated systems would be eliminated as the moving pipes would be carrying low-pressure steam at only pressure, and would be easier to keep steam-tight; and
* A simple type of very powerful locomotive would be created.[
The large-diameter pipe conveying the low-pressure steam from the high-pressure to the low-pressure cylinders acted also as a receiver, forming a buffer for the gas flow.
Independent ]cut-offs
Shorts are a garment worn over the human pelvis, pelvic area, circling the waist and splitting to cover the upper part of the legs, sometimes extending down to the knees but not covering the entire length of the leg. They are called "shorts" b ...
for the high-pressure and low-pressure cylinders were advocated by Mallet, but driving standards were inadequate and he later used combined cut-off control.
European versions
Large numbers of Mallet designs for narrow gauge railways were built, but in 1889 the first six standard gauge
A standard-gauge railway is a railway with a track gauge of . The standard gauge is also called Stephenson gauge (after George Stephenson), International gauge, UIC gauge, uniform gauge, normal gauge and European gauge in Europe, and SGR in Ea ...
examples were built by J A Maffei for the Swiss Central railways, and an 87 tonne banker (US: pusher) for the Gotthard Bahn, the last being the most powerful and heaviest locomotive in the world at the time. By 1892 110 Mallets were at work, of which 24 were standard gauge; by 1900 there were nearly 400, of which 218 were on standard gauge or Russian gauge
Russian(s) refers to anything related to Russia, including:
*Russians (, ''russkiye''), an ethnic group of the East Slavic peoples, primarily living in Russia and neighboring countries
*Rossiyane (), Russian language term for all citizens and peo ...
().
One of the examples in Germany was the class of s built by Maffei for Bavarian State Railways between 1913 and 1923.
Mallet designs were popular in Hungary, too. 30 of were built between 1898–1902 (the last one served until 1958). was a (1B)B locomotive in service between 1905–1969 and until 1962. The strongest Mallet locomotives in Europe were the members of the MÁV 601
Hungarian State Railways ( hu, Magyar Államvasutak, MÁV) is the Hungarian national railway company, with divisions "MÁV START Zrt." (passenger transport), "MÁV-Gépészet Zrt." (maintenance), "MÁV-Trakció Zrt." and "MÁV Cargo Zrt" (freig ...
which was built for the Hungarian State Railways
Hungarian State Railways ( hu, Magyar Államvasutak, MÁV) is the Hungarian national railway company, with divisions "MÁV START Zrt." (passenger transport), "MÁV-Gépészet Zrt." (maintenance), "MÁV-Trakció Zrt." and "MÁV Cargo Zrt" (freig ...
, it was a locomotive. With their 22.5 meter length, 163.3 tonnes total weight and 2200 KW power, the MÁV 601 was the biggest, the heaviest and most powerful steam locomotive built before and during the First World War in Europe.
North American versions
The first Mallet locomotive in the United States was Baltimore & Ohio Railroad
The Baltimore and Ohio Railroad was the first common carrier railroad and the oldest railroad in the United States, with its first section opening in 1830. Merchants from Baltimore, which had benefited to some extent from the construction of ...
number 2400, built by Alco
The American Locomotive Company (often shortened to ALCO, ALCo or Alco) was an American manufacturer of locomotives, diesel generators, steel, and tanks that operated from 1901 to 1969. The company was formed by the merger of seven smaller locomo ...
in 1904. Nicknamed "Old Maude", it was a 0-6-6-0 weighing and with axle load
An axle or axletree is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In the former case, bearing ...
s of . Received negatively at first due to speed limitation arising from the short wheelbase and stiff suspension, it gained support during service, and it was soon followed by Baldwin examples, and then steadily heavier and more powerful successors.
In Canada, the Canadian Pacific Railway
The Canadian Pacific Railway (french: Chemin de fer Canadien Pacifique) , also known simply as CPR or Canadian Pacific and formerly as CP Rail (1968–1996), is a Canadian Class I railway incorporated in 1881. The railway is owned by Canadi ...
experimented with an unusual design of Mallet promoted by H.H. Vaughan, then Chief Mechanical Officer and Assistant to the CPR Vice-President. Their in-house compound 0-6-6-0 design located both the high and low pressure cylinders adjacent to one another in the center of the locomotive driving opposite directions. Produced in the CPR's Angus shops, road numbers 1950 to 1954 were outshopped between 1909 and 1911. An additional "simple" (as opposed to compound) unit with road #1955 featuring the same arrangement was also produced. These were used in helper service in the Rockies and Selkirks. The units were unpopular with crews owing to frequent steam leakages and derailments resulting from the lack of pilot wheels. While not an outright failure these were considered an unsuccessful design, and by 1916-1917 these units had been converted to a conventional 2-10-0 arrangement. These six locomotives were ultimately the only articulated locomotives operated by a Canadian railway.
As weight and power and length increased, there were experiments with flexible boiler casings; from 1910 the Santa Fe road introduced jointed-boiler 2-6-6-2 locomotives weighing , with a long boiler barrel, with a firetube reheater and a firetube feedwater section in front, each separated by a blank section, and variants of a telescopic or bellows type boiler casing. These were unsuccessful, and later engines used conventional boilers.
The largest compound Mallets were ten 2-10-10-2s built for the Virginian by Alco in 1918; in pairs they pushed coal trains headed by a 2-8-8-2. The AT&SF also had a number of compound 2-10-10-2's, assembled in their own shops from existing 2-10-2's using a kit, supplied by Baldwin, consisting of the front 10-wheel frame and a boiler extension.
Although compounds had been considered obsolescent since the 1920s, C&O thought them appropriate, in the late 1940s, for low-speed coal-mine pickup runs converging on the classification yard
A classification yard (American and Canadian English ( Canadian National Railway use)), marshalling yard (British, Hong Kong, Indian, Australian, and Canadian English ( Canadian Pacific Railway use)) or shunting yard (Central Europe) is a railway ...
at Russell, Kentucky
Russell is a home rule-class city on the south bank of the Ohio River in Greenup County, Kentucky, United States. The population was 3,380 as of the 2010 census, down from 3,645 in 2000. Russell is a suburb of Ashland and part of the Hunting ...
.["Locomotive Notes," '']Trains
In rail transport, a train (from Old French , from Latin , "to pull, to draw") is a series of connected vehicles that run along a railway track and transport people or freight. Trains are typically pulled or pushed by locomotives (often know ...
'' magazine, August 1948 Only ten (of 25 originally ordered) were built before the order was cancelled, the last delivered in September 1949. The final loco, Chesapeake and Ohio 1309
Western Maryland Scenic Railroad 1309 is a compound articulated class "H-6" " Mallet" type steam locomotive with a 2-6-6-2 (Whyte notation) wheel arrangement. It was built by the Baldwin Locomotive Works in 1949 and originally operated by the ...
, is preserved on the Western Maryland Scenic Railroad
The Western Maryland Scenic Railroad (WMSR) is a heritage railroad based in Cumberland, Maryland, that operates passenger excursion trains and occasional freight trains using both steam and diesel locomotives over ex-Western Maryland Railway (W ...
. The 1309 was also the last steam locomotive that Baldwin built for the North American market.
The last compound Mallets to remain in use on a major North American railroad were the N&W class Y6b 2-8-8-2 locomotives, retired in July 1959. Norfolk & Western 2156
Norfolk & Western 2156 is a four-cylinder compound articulated class "Y6a" " Mallet" type steam locomotive with a 2-8-8-2 (Whyte notation) wheel arrangement. The Norfolk & Western Railway built it in 1942 at its Roanoke Shops in Roanoke, Virgin ...
is the sole surviving Y6a, preserved at the National Museum of Transportation
The National Museum of Transportation (NMOT) is a private, 42-acre transportation museum in the Kirkwood suburb of St. Louis, Missouri. Founded in 1944, it restores, preserves, and displays a wide variety of vehicles spanning 15 decades of Amer ...
in St. Louis.
Simple expansion versions in the US
By about 1920, the U.S. version of the Mallet as a huge slow-speed pusher had reached a plateau; the size of the low-pressure cylinders became a limiting factor even on the large loading gauge
A loading gauge is a diagram or physical structure that defines the maximum height and width dimensions in railway vehicles and their loads. Their purpose is to ensure that rail vehicles can pass safely through tunnels and under bridges, and ke ...
permitted in the U.S., and reciprocating masses posed serious dynamic problems above walking pace. Moreover, there were adhesion stability problems where the front engine tended to slip and then stall uncontrollably because of an imbalance of tractive effort and axle load, accentuated by the drawbar reaction, and inability of the intermediate steam receiver to accommodate the sudden pressure change. This was further worsened by dynamic instability of the front end in running.
The Chesapeake and Ohio Railway introduced 25 simple (non-compound expansion) 2-8-8-2 locomotives in 1924 and 20 more in 1926. Although the simple-expansion concept diverged from Mallet's original patent, the locomotives were clearly a continuation of the concept and were still referred to as "Mallet" locomotives. As the front truck cylinders were now using boiler pressure steam, special arrangements were necessary to deliver it, through the truck pivot pin where only radial movement took place. These new locomotives took over service on a division; a single locomotive hauled in five hours.
Mallet development culminated in 1941 with the 4-8-8-4 Big Boy type on the Union Pacific
The Union Pacific Railroad , legally Union Pacific Railroad Company and often called simply Union Pacific, is a freight-hauling railroad that operates 8,300 locomotives over routes in 23 U.S. states west of Chicago and New Orleans. Union Paci ...
railroad. They weighed with a tender; at long (including the tender), they could only be turned on a few of the system's turntables
A phonograph, in its later forms also called a gramophone (as a trademark since 1887, as a generic name in the UK since 1910) or since the 1940s called a record player, or more recently a turntable, is a device for the mechanical and analogu ...
. They could develop on the drawbar at and were designed for a top speed of , though they rarely saw these speeds. Slightly shorter but even heavier and more powerful were 2-6-6-6
The 2-6-6-6 (in Whyte notation) is an articulated locomotive type with two leading wheels, two sets of six driving wheels and six trailing wheels. Only two classes of the 2-6-6-6 type were built. One was the "Allegheny" class, built by the Lima L ...
s built by Lima
Lima ( ; ), originally founded as Ciudad de Los Reyes (City of The Kings) is the capital and the largest city of Peru. It is located in the valleys of the Chillón River, Chillón, Rímac River, Rímac and Lurín Rivers, in the desert zone of t ...
for the C&O and the Virginian between 1941 and 1948, which weighed and could produce up to at .
The last Mallets
These U.S. locomotives were paralleled to some extent by heavy-haul versions in the USSR
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nationa ...
, though without any attempt at faster running. Two 2-8-8-4 examples built in Russia in 1954–55 were probably the last Mallets built in Europe.
Other continents
Although it had found early favor in Europe, especially on lightly engineered railways, the Mallet type was generally superseded by the Garratt
A Garratt (often referred to as a Beyer Garratt) is a type of steam locomotive invented by British engineer Herbert William Garratt that is articulated into three parts. Its boiler, firebox, and cab are mounted on a centre frame or "bridge ...
locomotive by the mid-1920s.
In the Dutch East Indies, now the Republic of Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...
, several types and sizes remained in use into the 1980s. In 1962, the Indonesian state railways DKA ordered a series of 0-4-4-2s, basically an updated version of the earlier Dutch design, for the old Atjeh (now Aceh) tramway. Constructed by Nippon Sharyo in Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
, they were the only Mallets built in Asia
Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...
. In contrast to the rest of the Indonesian railways it has a gauge of , as to for the rest of the Archipelago. Smaller Mallets were used by plantations and other industries, all of the 0-4-4-0 type. These ran mostly on and gauge networks. But meanwhile in Garut - Cibatu in West Java, DKA ordered bigger 2-6-6-0
Under the Whyte notation for the classification of steam locomotives by wheel arrangement, is a locomotive with one pair of unpowered leading wheels, followed by two sets of three pairs of powered driving wheels and no trailing wheels. The whe ...
Mogul Mallets Like the extinct mallet tank Indonesian Railways CC10 Class class and the even larger CC50 class along with the All extinct 2-8-8-0 Bull Moose like DD50 - 52 class. Only 3 CC50 engines survived. It was CC 50 01 ( Prototype ) in the Transportation museum in TMII, CC 50 22 in Railway Museum (Netherlands)
The Railway Museum ( nl, Het Spoorwegmuseum) in Utrecht is the Dutch national railway museum. It was established in 1927 and since 1954 has been housed in the former Maliebaan station.
History
The museum was established in 1927 and was initiall ...
and CC 50 29 in the Ambarawa Railway Museum
The Ambarawa Railway Museum, ( id, Museum Kereta Api Ambarawa, officially named Indonesian Railway Museum by the Indonesian Railway Company) is a museum located in Ambarawa in Central Java, Indonesia. The museum focuses on the collection of ste ...
. But unlike the CC 50 class, all of the CC 10s & DD 50 -52s was sadly cut up for scrap. We still hope for this engine to be preserved in railway museums, but there is a chance to make a new built of the class.
Mallets were employed in Brazilian , tight-radius railroads.
One Mallet ran in New Zealand, and is preserved at Glenbrook Vintage Railway
The Glenbrook Vintage Railway (GVR) is a heritage steam railway in Glenbrook, New Zealand.
The GVR is run by a trust board of three trustees elected and appointed from Railway Enthusiasts Society (RES) membership. The board appoints a general m ...
, Auckland
Auckland (pronounced ) ( mi, Tāmaki Makaurau) is a large metropolitan city in the North Island of New Zealand. The List of New Zealand urban areas by population, most populous urban area in the country and the List of cities in Oceania by po ...
.
Three Mallets ran in Australia, including one on the Magnet Tramway in Tasmania
)
, nickname =
, image_map = Tasmania in Australia.svg
, map_caption = Location of Tasmania in AustraliaCoordinates:
, subdivision_type = Country
, subdi ...
.
Preservation
Several Mallets have been preserved, some in operational condition. A number of the Union Pacific " Big Boys", are preserved, including one overlooking Omaha, Nebraska
Omaha ( ) is the largest city in the U.S. state of Nebraska and the county seat of Douglas County. Omaha is in the Midwestern United States on the Missouri River, about north of the mouth of the Platte River. The nation's 39th-largest cit ...
where UP is based. In January 2014, Big Boy #4014 was removed from its museum ground parking track in Pomona, California, and hauled to Cheyenne, Wyoming, for restoration to operating condition; this was completed in May 2019. No. 4014 is the largest, heaviest, and most powerful operational steam locomotive in the world.
Two of Union Pacific's Challengers survived into preservation. Challenger #3985 was the largest operational steam locomotive in the world until the restoration of UP 4014. It was taken out of service in October 2010 due to mechanical problems and retired in January 2020. As of May 2022, No. 3985 is being donated to the Railroading Heritage of Midwest America.
Chesapeake & Ohio 2-6-6-2 #1309, the last domestic steam locomotive built by Baldwin, was scheduled for restoration in September 2017. "New as they were, the last C&O steam engines never got adequate maintenance, lengthening the list of work needed to bring 1309 back to life." The locomotive was fired up and moved under her own steam on December 31, 2020, the first time she had done so in 64 years. On December 17, 2021, C&O 1309 (now WMSR 1309) entered excursion service on the Western Maryland Scenic Railroad
The Western Maryland Scenic Railroad (WMSR) is a heritage railroad based in Cumberland, Maryland, that operates passenger excursion trains and occasional freight trains using both steam and diesel locomotives over ex-Western Maryland Railway (W ...
.
The single surviving example of a cab-forward Mallet is Southern Pacific 4294
Southern Pacific 4294 is a class " AC-12" 4-8-8-2 Cab forward type steam locomotive that was owned and operated by the Southern Pacific Railroad (SP). It was built by the Baldwin Locomotive Works in March 1944 and was used hauling SP's trains o ...
, on display at the California State Railroad Museum
The California State Railroad Museum is a museum in the state park system of California, United States, interpreting the role of the "iron horse" in connecting California to the rest of the nation. It is located in Old Sacramento State Historic ...
in Sacramento, California
)
, image_map = Sacramento County California Incorporated and Unincorporated areas Sacramento Highlighted.svg
, mapsize = 250x200px
, map_caption = Location within Sacramento C ...
.
Several smaller logging-railroad Mallets have been restored to operating condition, including Black Hills Central #110 in Hill City, South Dakota, Clover Valley Lumber Company #4 in Sunol, California, and Deep River Logging "Skookum" #7 in Garibaldi, Oregon
Garibaldi ( ) is a city in Tillamook County, in the U.S. state of Oregon. The population was 797 at the 2020 census.
History
The indigenous Tillamook people have lived along the Oregon coast –including the Tillamook Bay– for about 12,000 yea ...
.
CC 50 22, an early Dutch-built Indonesian Mallets has been returned to the Netherlands and is now exhibited in the Dutch Railway Museum
The Railway Museum ( nl, Het Spoorwegmuseum) in Utrecht is the Dutch national railway museum. It was established in 1927 and since 1954 has been housed in the former Maliebaan station.
History
The museum was established in 1927 and was initiall ...
but meanwhile, the other 2 like CC 50 01 is preserved in Transportation Museum in TMII and CC 50 29 is preserved in the Ambarawa Railway Museum.
Another industrial type has been purchased and restored by the Statfold Barn Railway
The Statfold Barn Railway is a narrow gauge railway based near Tamworth, Staffordshire and partially in Warwickshire, England. Founded by engineering entrepreneur Graham Lee and his wife Carol at their farm-based home, they originally designed wh ...
in the UK. This saw its first operation in Europe in 2011 and after initial trials on the owners' railway, was transferred to the Welsh Highland Railway
The Welsh Highland Railway (WHR) or Rheilffordd Eryri is a long, restored narrow gauge heritage railway in the Welsh county of Gwynedd, operating from Caernarfon to Porthmadog, and passing through a number of popular tourist destinations ...
as its power is better suited to that railway.
A number of Mallets were constructed for the Nordhausen Wernigerode Eisenbahn, now part of the Harz Narrow Gauge Railways system in Germany. Running numbers 99 5901-3 and 99 5906 are in working order.
The Blonay–Chamby museum railway
The Blonay–Chamby Museum Railway (french: Chemin de fer-musée Blonay-Chamby, BC) is a short steep but adhesion worked metre gauge heritage railway operated as part of the Blonay–Chamby Railway Museum using vintage steam and electric locomot ...
has two Mallets. First to be acquired was the Hanomag G 2x 3/3 No104. At 56 tonnes this locomotive was one of the largest steam metre gauge locos ever built in Europe. It was in service until 1979, and as of September 2021 is still under restoration. There is also a G 2x 2/2 No.105 built by Maschinenfabrik Karlsruhe. As of September 2021 it hauls tourist trains on 5% grades.
ABPF-SC (Brazilian Association for Railroad Preservation – Santa Catarina branch) has restored a Mallet to working order. It hauls tourist steam trains on 3% grades. The first official train ran on April 30 2017.
Terminology
As a French-speaking Swiss, Mallet pronounced his name accordingly, something like "Ma-lay".
Mallet's original patent specifies compound expansion, but after his death in 1919 many locomotives (particularly in the United States) were articulated Mallet style without using compounding (for instance the Union Pacific Big Boy
The Union Pacific Big Boy is a type of simple articulated 4-8-8-4 steam locomotive manufactured by the American Locomotive Company (ALCO) between 1941 and 1944 and operated by the Union Pacific Railroad in revenue service until 1962.
The 25 Big ...
). When fleets of such locomotives appeared in the middle 1920s the trade press called them "Simple Mallets" — i.e., simple locomotives articulated like Mallets. The term "Mallet" continued to be widely used for simple as well as compound locomotives.
References
External links
Baldwin description of Mallet locomotives from 1912
Proctor, MN Steam Locomotive No. 225
* ttp://lakecountyhistoricalsociety.org/museums/view/mallet-steam-engine Lake County Historical Society Steam Locomotive No. 229
{{DEFAULTSORT:Mallet Locomotive
Steam locomotive types
Compound locomotives
Articulated locomotives