View source for 2-10-0

{{Short description|Locomotive wheel arrangement}}
{{Infobox steam wheel arrangement
| name             = 2-10-0 (Decapod)
| image            = WheelArrangement 2-10-0.svg
| alt              = Diagram of one leading wheel and five large driving wheels joined by a coupling rod
| caption          = Front of locomotive at left
| image2           = PRR I1s 4300.jpg
| alt2             = 
| caption2         = [[Pennsylvania Railroad]] class [[PRR I1s]], the most successful class of such locomotives in North America. Note the firebox placed above the rear drivers.
<!--Equivalent classifications-->
| hatnote          = 
| UIC/Germany/Italy= 1′E
| French/Spanish   = 150
| Turkish          = 56
| Swiss            = 5/6
| Russian          = 1-5-0
<!--First tank engine version-->
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| evolvedfrom      = 
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| mainbenefit      = 
| maindrawback     = 
<!--First tender engine version-->
| date2            = 1886
| country2         = United States
| locomotive2      = No. 1 & 2
| railway2         = [[Northern Pacific Railroad]]
| designer2        = Burnham, Parry, Williams & Company
| builder2         = Burnham, Parry, Williams & Company
| evolvedfrom2     = [[0-10-0]]
| evolvedto2       = [[2-10-2]]
| mainbenefit2     = Better stability than the [[0-10-0]]
| maindrawback2    = Small firebox
<!--First "True type" version-->
| date3            = 
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}}

Under the [[Whyte notation]] for the classification of [[steam locomotive]]s, '''2-10-0''' represents the [[wheel arrangement]] of two [[leading wheel]]s on one axle, ten powered and coupled [[driving wheel]]s on five axles, and no [[trailing wheel]]s. This arrangement was often named '''Decapod''', especially in the [[United States]], although this name was sometimes applied to locomotives of [[0-10-0]] "Ten-Coupled" arrangement, particularly in the [[United Kingdom]]. Notable German locomotives of this type include the war locomotives of [[DRB Class 52|Class 52]].

These locomotives were popular in [[Europe]], particularly in [[Germany]] and [[Russia]]; [[United Kingdom|British]] use of the type was confined to the period during and after [[World War II]]. In the [[United States]], the 2-10-0 was not widely popular but was a favorite of a small number of railroads which operated mostly in mountainous terrain.  Among these was the [[Erie Railroad]], a major Chicago to New York trunk line railroad, and the [[Pennsylvania Railroad]], whose heavily graded routes crossed the Allegheny Mountains.

The 2-10-0's main advantage was that five out of six of its axles were powered, meaning almost all the [[Adhesive weight|weight was available for traction]] rather than being distributed over pilot and trailing wheels. The long rigid [[wheelbase]] caused problems on tightly curved track, so [[Driving wheel#Flangeless wheels|blind drivers]] were the norm, either on the central axle, and/or on the second and/or fourth axles. Often [[lateral motion device]]s were attached to the leading drive axle.

The wheel arrangement's disadvantages included the [[Firebox (steam engine)|firebox]] size restriction caused by the lack of trailing wheel. This meant the firebox was fitted in between the wheels (common on earlier locomotives) and was long and narrow, or if mounted above the driving wheels, was wide and long but shallow. Many locomotives chose the latter option. A firebox mounted over the drivers also restricted the diameter of the driving wheels, which in turn limited speed. As with the Consolidation (2-8-0), "chopping" at speed ensured a rough ride for the crew due to instability caused by the wheel arrangement. In fact, backing any locomotive without a trailing axle was restricted to under twenty miles per hour or less. Most 2-10-0s were not operated at speeds greater than 50&nbsp;mph (80&nbsp;km/h).

The type operated as freight engine, although locomotives in [[Germany]] and the [[United Kingdom]] proved capable of hauling [[Train|passenger train]]s.

== United States ==
[[File:Pennsylvania Railroad Steam Locomotive -4483 (1).jpg|thumb|Pennsylvania Railroad I1s Locomotive]]
The first Decapods were built for the [[Lehigh Valley Railroad]] in the late-1860s. They proved too rough on the track because of their long coupled [[wheelbase]].<ref>{{cite book
  |last1=Solomon  |first1=Brian
  |title=The Majesty of Big Steam
  |year=2015
  |publisher=[[Voyageur Press]]
  |page=102
}}</ref> No more followed for 19 years, until the [[Northern Pacific Railway]] bought two for use on the switchbacks over [[Stampede Pass]], while the {{convert|2|mi|km|1|adj=on}} tunnel was being built.{{sfnp|Armstrong|1978|pages=74–76}} In low-speed service where high tractive effort was critical, these Decapods were successful. Small numbers of other Decapods were built over the next twenty years, mostly for service in steeply [[grade (slope)|grade]]d mountainous areas where power at low speeds was the requirement. The type did not prove as popular as the successful Consolidation ([[2-8-0]]) type. Among Decapod users was the [[Atchison, Topeka and Santa Fe Railway]]. The engines were [[tandem compound locomotive|tandem compound]]s but their ongoing reversing limitations became the genesis of the [[2-10-2]] wheel arrangement.

[[File:Seaboard 544.jpg|thumb|Seaboard Air Line #544, one of over 200 undelivered [[Class Ye 2-10-0|Russian Decapods]]. It resides at the [[North Carolina Transportation Museum]]. Note the smaller boiler diameter, compared to the I1s above]]
The first boost in the number of Decapods occurred when [[Russian Empire|Imperial Russia]] ordered approximately 1,200 [[Russian locomotive class Ye|Decapods]] from American builders during [[World War I]]. When the [[October Revolution|Bolshevik revolution]] occurred in 1917, 857 had already been delivered,{{sfnp|Drury|1993|page= 176 }} but more than 200 were either awaiting shipment or were in the process of construction.{{sfnp|Drury|1993|page= 176 }} These stranded locomotives were adopted by the [[United States Railroad Administration]] (USRA), the body created by the Government to oversee and control the railroads during the War, converted to American standards, and put to use on American railroads. Small and light-footed, these Russian decapods proved popular with smaller railroads, and many of them remained in service long after the USRA's control of the railroads ceased.<ref>{{cite book |last1=Prince |first1=Richard |title=Seaboard Air Line Railway: Steam Boats, Locomotives, and History |date=2000 |publisher=Indiana University Press |location=United States |isbn=9780253336958 |pages=268 |url=https://books.google.com/books?id=MM2ph3S2V2cC&q=2-10-0%20Detroit%2C%20Toledo%20%26%20Ironton%20Railroad&pg=PA165 |access-date=14 July 2019}}</ref> Many indeed lasted until the end of steam on those railroads.

[[File:544boilergap.jpg|thumb|left|The same [[Class Ye 2-10-0|Russian Decapod]], showing the large gap between the boiler and drivers, typical of locomotives designed for Russia]]
Swengel suggested the 2-10-0 arrangement was 'obsolete' by 1916, when the Pennsylvania Railroad commenced an experiment with a 2-10-0 locomotive at its Juniata plant.{{sfn|Swengel|1967|pages=190-191}} Most 10 coupled engines constructed for U.S. railroads during World War I were of the USRA 2-10-2 arrangement, but the PRR committed to 122 of the 2-10-0s.{{sfn|Swengel|1967}}{{sfn|Staufer|1962|page=65}} Swengel argued this commitment to the 2-10-0, nicknamed "Deks", was controversial even in 1916 and was more so in 1922 when the PRR placed additional orders. The PRR was soon the biggest user of Decapods in the United States. The type was ideally suited to the Pennsy's heavily graded [[Allegheny Mountains]] routes, which required lugging ability according to tractive effort, not speed according to horse power.

The PRR bought 598 2-10-0s including 123 built at its own shops. In one of the largest locomotive orders ever, the rest came from the [[Baldwin Locomotive Works]]. The PRR 2-10-0s weighed {{convert|386100|lb|t|lk=in|abbr=on}} and developed about {{convert|90000|lbf|kN|abbr=on|lk=in|sigfig=4}} of tractive effort{{efn-lr|Maximum cutoff as built was nominally 50% (with small auxiliary ports to aid in starting) so "tractive effort" couldn't be calculated in the usual way. Cutoff on most engines was eventually extended and PRR claimed 96,000 lb for them.}} with an axle loading of over {{convert|70000|lb|t|abbr=on}}. The engines steamed at {{convert|250|psi|MPa|abbr=on|lk=in|sigfig=3}} and had a relatively large superheater. The grate area of about {{convert|70|sqft|abbr=on}} was on the small side, but a mechanical stoker partly compensated for this.{{sfn|Swengel|1967}}

The PRR decapod, class [[PRR I1s|I1s]], was unlike the Russian decapod; it was huge, taking advantage of the PRR's heavy trackage and high [[axle load]]ing, with a fat, free-steaming boiler that earned the type the nickname of 'Hippos' on the PRR. Two giant cylinders (30½ x 32&nbsp;inch) gave the I1s power and their tenders permitted hard and long workings between stops. They were unpopular with the crews, for they were hard riding.{{sfn|Staufer|1962}} The last operations on the PRR were 1957.{{sfn|Staufer|1962}}

A small number of other Decapods were ordered by other railroads; the I-2 Decapods built for the [[Western Maryland Railway]] were the largest ever built, at almost {{convert|420000|lb|t|abbr=on}} weight, and are a notable exception to the rule of thumb for the comfort of the ride on a 2-10-0 wheel arrangement, crews said the engines cruised smoothly up to 50&nbsp;mph without becoming a rough ride. (After the running gear was redesigned by the WM) The WM's I-2 are also noted as the strongest Decapods ever built, at 96,315&nbsp;lbs of tractive effort. (Not to be confused with the 10 Russian Decapods the WM held in their roster, which were standard Russian Decapods aside from heavier steel frames the WM used to replace the original cast iron frames, the new frames also made the WM Russian Decapods 2 inches longer than other Russian Decapods)

Baldwin developed two standard 2-10-0s for railroads with low axle-load requirements.<ref name="Drury-steam351" >King, E.W., Jr. in Drury p. 351</ref>

Thirteen Decapod locomotives survive in the US, including two Baldwin standards, six Russian Decapods and one PRR I1. Two, [[Great Western 90 2-10-0 decapod|Great Western 90]], a Baldwin Decapod at the [[Strasburg Rail Road]], and [[Frisco 1630]], a Russian Decapod at the [[Illinois Railway Museum]], are operational. One Decapod survives as a static exhibit at the North Carolina Transportation Museum in Spencer, North Carolina ([[Seaboard Air Line Railroad|Seaboard Air Line]] 2-10-0 #544).

=== Preserved Decapods in the United States ===
*1621 is on display at the National [[National Museum of Transportation]] - St. Louis, MO
*1625 is on display at the [[Museum of the American Railroad]] - Frisco, TX
*[[St. Louis-San Francisco 1630|1630]] is operated by the Illinois Railway Museum - Union, IL.
*[[Great Western 90|90]] is operated by Strasburg Railroad - Strasburg, PA.
*[[Pennsylvania Railroad I1 class|I1 class]] 4483 is at [[Hamburg, New York]].

===Proposed/Unbuilt (US)===
[[L.D. Porta]] proposed a 2-10-0, triple expansion [[Advanced steam technology|Modern steam locomotive]] as a "second generation" [[freight train|fast-freight]] locomotive for the [[ACE 3000]] project based on his previous works.

== Germany ==
[[File:Locomotive BR50-3648-8.jpg|thumb|A BR50]]
The 2-10-0 arrangement was a very popular one in Germany. The first were built by the individual state railways from 1915 to 1918, and these later became the [[Deutsche Reichsbahn|DRG]] [[Prussian G 12|BR58]]. The DRG then produced a number of standard classes of 2-10-0s: the heavy 3-cylinder [[DRG Class 44|BR44]] (1753 built), the two-cylinder version [[DRG Class 43|BR43]] (35 built), and the lightweight [[DRB Class 50|BR50]] (3164 built). During wartime, the BR44 and BR50 designs were simplified as ÜK (''Übergangs Kriegslokomotiven'', or interim war locomotives). By 1941, it was clear that even these were too complicated, expensive, time-consuming to build, and used too much material in short supply, so new ''[[Kriegslokomotive]]'' (war locomotive) designs were developed: the lightweight [[DRB Class 52|BR52]] (7794 built) and the intermediate weight [[DRG Class 42|BR42]] (859 built).

Postwar locomotives of these types, particularly the BR 52, were spread all over Europe and were taken into service by the railways of many different countries:
* BR44 in France, [[SNCF 150X]].
* BR50 in Belgium, [[National Railway Company of Belgium|NMBS/SNCB]] class 25; in Denmark, [[DSB (railway company)|DSB]] class N.
* BR52 in Austria, [[Austrian Federal Railways|ÖBB]] class 52; in Belgium, NMBS/SNCB class 26; in Norway, [[Norwegian State Railways (1883–1996)|NSB]] Class 63.

{{Clear}}

== United Kingdom ==
[[File:BR 9F Crosti 2-10-0 at Wellingborough in 1959.jpg|thumb|left|[[BR Standard Class 9F 92020-9|BR Standard Class 9F with the experimental Franco-Crosti boiler]]]]
Locomotives with ten driving wheels were rare in British railway history. In 1913 an initial design for [[L&YR 2-10-0 (Hughes)|a four-cylinder 2-10-0]] of {{convert|53328|lbf|-3}} [[tractive effort]] was produced by the [[Lancashire and Yorkshire Railway]], but none were built. This had been inspired by Jean-Baptiste Flamme's {{illm|Type 36 (SNCB)|fr}} 2-10-0s working in Belgium and used a similar tapered boiler, with the round-topped firebox almost filling the loading gauge.<ref>{{Cite book
  |title=Locomotives That Never Were
  |first=Robin  |last=Barnes
  |year=1985
  |publisher=[[Jane's]]
  |isbn=0-7106-0326-6
  |chapter=L&YR Hughes 2-10-0
  |pages=24–25
}}</ref> The [[WD Austerity 2-10-0|first 2-10-0]] was built during the Second World War, as a variant of the "Austerity" 2-8-0 for lightly built railways.{{sfnp|Boddy|Brown|Neve|Yeadon|1983|p=147}}

The only other 2-10-0 type was the 251-strong [[BR Standard Class 9F|Standard class 9F]] introduced by [[British Railways]] in 1954.{{sfnp|Walford|Harrison|2008|p=76}} The class included [[BR standard class 9F 92220 Evening Star|92220 ''Evening Star'']], the last steam locomotive built for British Railways, in 1960;{{sfnp|Walford|Harrison|2008|p=206}} and 92203 (named ''Black Prince'' when preserved), which in 1983 set a record for the heaviest steam locomotive-hauled train in Britain when it started a 2,162-ton train at [[Foster Yeoman]] quarry in Somerset.{{sfn |Shepherd |1983 |p=256}}

{{Clear}}

== Finland ==
[[Image:Tr2Locomotive.jpeg|thumb|right|ALCO No 75214 Tr2 1319 at the [[Finnish Railway Museum]]]]
The [[VR Group|State Railroads]] of [[Finland]] purchased 20 American Decapods after [[World War II|WWII]] - these were originally built for the Soviet Union, but never delivered to them. Of the 20 engines, 10 were made by [[Baldwin Locomotive Works|Baldwin]], 10 by [[American Locomotive Company|Alco]]. Since they were originally built for the USSR, they had the correct gauge for Finland, too ({{Track gauge|1524mm|lk=on}} exactly). One (Alco # 75214, 1947) is preserved at the [[Finnish Railway Museum]] in [[Hyvinkää]], Finland. The Finnish designation was '''Tr2'''.

The locomotive was nicknamed ''Truman'' in Finland. It was used for hauling heavy freight trains.

== France ==
From 1910 to 1951, the French industry built more than 500 decapods for three railway companies (Paris-Orléans, Nord, Est) and for the national railways ([[SNCF]]). Moreover, at the end of [[World War II]], SNCF inherited more than 200 units of German decapods built in France, mostly BR 44. The last decapod, a SNCF 150P, was withdrawn in 1968. All 2-10-0s, of French or of German design, proved reliable and powerful in service. One can notice that some engines of the Paris-Orléans company were dedicated to passenger service on difficult mountain lines.

{{Clear}}

==Poland==
[[File:HCP Ty23.jpg|thumb|right|PKP class Ty23 in front of the H. Cegielski Poznań works]]
[[File:POL Karsznice Ty246.jpg|thumb|right|Preserved PKP class Ty246]]
Between early 1920s and 1958 Polish industry delivered to [[Polish State Railways|PKP]] some 1200 decapods of classes {{ill|PKP class Ty23|lt=Ty23|de|PKP-Baureihe Ty23|pl|Ty23}}, {{ill|PKP class Ty37|lt=Ty37|de|PKP-Baureihe Ty37|pl|Ty37}}, {{ill|PKP class Ty45|lt=Ty45|de|PKP-Baureihe Ty45|pl|Ty45}} and {{ill|PKP class Ty51|lt=Ty51|de|PKP-Baureihe Ty51|pl|Ty51}}. PKP also operated German decapods BR 52 ([[PKP class Ty2|Ty2]]) and [[DRB_Class_42|BR 42]] (Ty3), as well as American ones ({{ill|PKP class Ty246|lt=Ty246|pl|Ty246}}, nicknamed "Trumman"). They were used to work the heaviest goods trains.

{{Clear}}

==Romania==
[[File:CFR 150.038 romanian heavy freight locomotive (DR 50 class).jpg|thumb|right|Romanian 150.000 Class]]
After the [[Second World War]], [[Romania]] built the 150.000 Class, after [[DRB Class 50]]. A total of 282 locomotives were built between 1946 and 1960, at [[FAUR|Malaxa]] (later ''23 August Works'') in [[Bucharest]], and in [[Reşiţa]].<ref>[http://www.railwayfan.ro/aburi/html/150_000.html 150.000 Class Locomotive] {{Webarchive|url=https://web.archive.org/web/20120415045934/http://www.railwayfan.ro/aburi/html/150_000.html |date=2012-04-15 }} at railwayfan.ro {{in lang|ro}}</ref>

Builder details:
* 150.001-150.050 Reşiţa
* 150.051-150.081 Malaxa
* 150.082-150.282 Reşiţa

{{Clear}}

== Soviet Union ==
[[File:Parovoz-El-629.jpg|thumb|Steam Locomotive YeL 629 in [[Ussuriysk]]]]

2-10-0 were fairly common freight locomotives in the former Soviet Union. They came from several sources: US imports ([[Class Ye 2-10-0|class Ye]] ({{langx|ru|серия Е}}), built by ALCO and Baldwin, respectively), German war trophy DRB 52 class locomotives (what became the Soviet TE-series) and locally built. The locally built 2-10-0 locomotives were represented by some TE (built from captured German parts), SO (Sergo Ordjonikidze) and L (Lebedyanski)–series locomotives. The [[Soviet locomotive class L|L-series]] locomotives were one of the more advanced steam locomotives built in the former Soviet Union. They used an automatic stoker to feed coal and had a relatively low axle load (18 tonnes or 40,000&nbsp;lb) to be compatible with the war-torn railroads of the former Soviet Union. Several examples of these locomotives are still preserved in working order.

There is a 2-10-0 Lebedyanski series locomotive L 4657, marooned in a siding at Port Baikal.<ref>{{Google maps|url= https://www.google.com/maps/place/Parovoz/@51.870826,104.8110227,3a,75y/data=!3m8!1e2!3m6!1sAF1QipMylkezRdekqvsoDCHWb-Cfa8DFOhp5MUdE_R0x!2e10!3e12!6shttps:%2F%2Flh5.googleusercontent.com%2Fp%2FAF1QipMylkezRdekqvsoDCHWb-Cfa8DFOhp5MUdE_R0x%3Dw129-h86-k-no!7i5184!8i3456!4m5!3m4!1s0x5da887b18c461b37:0x62f529f7c4708ce3!8m2!3d51.8706569!4d104.8111823?hl=en
|title= Parovoz |access-date=8 September 2020}}
</ref>

{{Clear}}

==Footnotes==
{{Notelist-lr}}

{{Reflist}}

==References==
* {{cite book |last=Armstrong |first=John |year=1978 |title=Creative Model Railroad Design |location=Waukesha, Wisconsin |publisher=Kalmbach Publishing Company |isbn=0-89024-538-X}}
*{{cite book |last1=Boddy |first1=M.G. |last2=Brown |first2=W.A. |last3=Neve |first3=E. |last4=Yeadon |first4=W.B. |editor-last=Fry |editor-first=E.V. |title=Part 6B: Tender Engines - Classes O1 to P2 |series=Locomotives of the L.N.E.R. |date=November 1983 |publisher=[[Railway Correspondence and Travel Society|RCTS]] |location=Kenilworth |isbn=0-901115-54-1}}
*{{Drury-North American Steam|pages=176, 351}}
*{{cite book |title=A Brush With Steam |first=David |last=Shepherd |author-link=David Shepherd (artist) |year=1983 |publisher=David and Charles |isbn=978-0-7153-8157-1}}
* {{cite book |last=Staufer |first=Alvin F. | title=Pennsy Power: Steam and Electric Locomotives of the Pennsylvania Railroad 1900-1957| url=https://archive.org/details/pennsypowersteam00stau| url-access=registration| year=1962}}
* {{cite book |last=Swengel |first=F.M. |title=The American Steam Locomotive, Vol. 1, The Evolution of the Steam Locomotive| publisher=MidWest Rail Publications| location=Davenport, Iowa| year=1967}}
*{{cite book |last1=Walford |first1=John |last2=Harrison |first2=Paul |title=Volume Four: The 9F 2-10-0 Class |series=A Detailed History of British Railways Standard Steam Locomotives |year=2008 |publisher=[[Railway Correspondence and Travel Society|RCTS]] |location=Bristol |isbn=978-0-901115-95-9}}
* {{cite book| author=Woods, Don| title=I remember Pennsy| publisher=Audio-Visual Degins| location=Earlton| year=1973 }}

==External links==
{{Commons category}}
* [https://web.archive.org/web/20041216201044/http://www.irm.org/cgi-bin/rsearch.cgi?steam=St.+Louis-San+Francisco+Railroad=1630 Illinois Railway Museum's roster page for SLSF 1630 (the operable 2-10-0)]

{{Whyte types}}
{{Authority control}}

[[Category:Whyte notation|10,2-10-0]]
[[Category:2-10-0 locomotives| ]]
[[Category:1867 in rail transport]]
[[Category:1′E locomotives| ]]