- 2-10-10-2
Under the
Whyte notation for the classification ofsteam locomotive wheel arrangement s, a 2-10-10-2 is a locomotive with twoleading wheel s, two sets of tendriving wheel s, and a pair oftrailing wheel s.Other equivalent classifications are:
UIC classification : 1EE1 (also known asGerman classification andItalian classification )French classification : 150+051Turkish classification : 56+56Swiss classification : 5/6+5/6The equivalent
UIC classification is refined to (1'E)E1' for Mallet locomotives. All 2-10-10-2 locomotives have beenarticulated locomotive s,Mallet locomotives in particular.This wheel arrangement was rare. Only two classes of 2-10-10-2 locomotives have been built; the
Atchison, Topeka and Santa Fe Railway 's 3000 class, and theVirginian Railway 's class AE.ATSF 3000 class
This class of ten 2-10-10-2 locomotives were actually rebuilt from more conventional
2-10-2 Baldwin-built locomotives by theAtchison, Topeka and Santa Fe Railway in1911 .Although they appeared to have exceedingly long boilers, the barrel in front of the rear set of cylinders actually contained first a primitive
superheater for further heating the steam before use; the steam was carried forward from the boiler proper by outside steam pipes as shown in the photograph. Also contained in this space was a reheater to give additional energy to the high-pressure exhaust before it was fed to the forward low-pressure cylinders.In front of that, there was a
feedwater heater , a space where cold water from the tender could be warmed before being injected into the water proper. This worked similarly to the boiler itself; the firetubes passed through the feedwater tank.The experiment was decidedly unsuccessful, and the locomotives were rebuilt back to 2-10-2s during
1915 –1918 .pecifications
* Road numbers: 3000–3009
* Driver diameter: 57 in (1.45 m)
* Weight: 616,000 lb (279,400 kg = 279.4 t)
* Tractive effort: 111,600 lbf (496 kN)
* Boiler pressure: 225 lbf/in² (1.55 MPa)
* Cylinder diameter: 28 in (711 mm) high pressure, 38 in (965 mm) low pressure
* Cylinder stroke: 32 in (813 mm)Virginian Railway class AE
These ten locomotives were built in
1918 by ALCo for theVirginian Railway . Due to size limitations en route, the locomotives were delivered without cab or the front, low pressure cylinders, which were installed on site. The low pressure cylinders at 48 inch (1.22 m) diameter were the largest ever used on a US locomotive; they had to be tilted slightly upward to provide sufficient clearance.As can be seen in the photograph, the tenders fitted were unusually small; this was to enable them to fit on the Virginian Railway's turntables.
This class were true
Mallet locomotive s, in that as well as being articulated between the forward, swinging engine unit and the rear fixed one, they were alsocompound locomotive s; the rear, high pressure cylinders exhausted their steam via a long pipe into the giant front cylinders. Like many compound locomotives, it could be operated in "simple" mode for starting; high pressure steam could be sent straight to those front cylinders at low speed, for additionaltractive effort .Unlike some other giant locomotives of the period, the immense boilers could generate enough steam to make the locomotive a success on the slow (8 mph or 13 km/h)
drag freight s it hauled. The locomotives remained in service until1952 .pecifications
* Road number: 800–809
* Driver diameter: 56 in (1.42 m)
* Weight on drivers: 617,000 lb (280 t)
* Locomotive weight: 684,000 lb (310 t)
* Locomotive & tender weight: 898,000 lb (407 t)
* Grate area: 109 ft² (10.1 m²)
* Cylinders: (2 HP) 30 in (762 mm) dia. × 32 in (813 mm) stroke (2 LP) 48 in (1220 mm) dia. × 32 in (813 mm) stroke
* Boiler Pressure: 215 lbf/in² (1.49 MPa)
* Tractive effort:147,200 lbf (655 kN) (compound); 176,600 lbf (786 kN) (simple)
* Tender capacity: 13,000 US gallons (49,000 L) water, 12 short tons (11 t) coalIn all, 18 examples of this locomotive type were built.
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