Editing 2-10-0 (section)

{{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
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<!--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
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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.