Virginian Other Articulated Locomotives in the USA


Class Details by Steve Llanso of Sweat House Media

Class AA (Locobase 291)

Data from VGN 8 - 1951 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also "Mallet Articulated Compound Locomotives, 2-6-6-0 ...", American Engineering and Railroad Journal, Volume 83, No 6, (June 1909), p. 261 and No. 9 (September 1909), pp. 357-359. (Thanks to Chris Hohl for his 30 May 2013 email asking me to clarify this class's tender capacities.) Works numbers were 48976-48977 in August 1909, 45978 in October, and 45979 in November.

Four-cylinder Mallet compounds that were not well loved by its firemen because they were hand-bombed and not superheated. They were delivered with tenders holding 14 tons (12.7 tonnes) of coal.

All but 503 received both mechanical stokers and superheaters later on. See Locobase 7487


Class AA - superheated (Locobase 7487)

Data from VGN 8 - 1951 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Thanks to Chris Hohl for his 30 May 2013 email asking me to clarify this class's tender capacities.)

As noted in Locobase 291, the Richmond engines were delivered with saturated boilers and their hand-bombed fireboxes required a lot of effort on part of the firemen. All but the 503 later received both mechanical stokers and superheaters later on. At some point, possibly when they were upgraded, these Mallets' tender capacities were increased to 15 tons.

Like the earlier compounds, these upgraded Mallets were retired on 31 December 1933.


Class AC (Locobase 3564)

Data from Wiener (1930) gives mixed data, including superheater heating surface but not including the flue tube count or size and Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 35, pp. 113-120 for highly detailed specs. (Thanks to Chris Hohl for his 30 June 2021 email correcting the engine wheel base and driver diameter.) Works numbers were 35302-35309 in October 1910.

Locobase 291 shows the first four 2-6-6-0 Mallets delivered by Richmond as saturated-boiler compounds. Baldwin's contribution featured its low-temperature smokebox superheater that provided some additional drying. 30 sq ft (2.8 sq m) of firebox heating surface came in the form of six arch tubes.

Drury (1993) notes that these locomotives were more powerful than many other 2-6-6-2s. On slow coal drags, their small drivers, lack of a trailing axle, and large LP cylinders weren't disabilities. They served the VGN for not quite 25 years before being retired in December 1933.

Principal Dimensions by Steve Llanso of Middle Run Media
ClassAAAA - superheatedAC
Locobase ID291 7487 3564
RailroadVirginian (VGN)Virginian (VGN)Virginian (VGN)
CountryUSAUSAUSA
Whyte2-6-6-02-6-6-02-6-6-0
Number in Class438
Road Numbers500-503500-502510-517
GaugeStdStdStd
Number Built438
BuilderAlco-RichmondVGNBaldwin
Year190919221910
Valve GearWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)22 / 6.7122 / 6.7121.34 / 6.50
Engine Wheelbase (ft / m)39.92 / 12.1739.92 / 12.1740.33 / 12.29
Ratio of driving wheelbase to overall engine wheelbase 0.55 0.55 0.53
Overall Wheelbase (engine & tender) (ft / m)73.23 / 22.3272.06 / 21.9674.70 / 22.77
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)312,000 / 141,521295,600 / 134,082356,800 / 161,842
Engine Weight (lbs / kg)330,000 / 149,686311,300 / 141,203385,300 / 174,769
Tender Loaded Weight (lbs / kg)172,000 / 78,018172,000 / 78,018181,700 / 82,418
Total Engine and Tender Weight (lbs / kg)502,000 / 227,704483,300 / 219,221567,000 / 257,187
Tender Water Capacity (gals / ML)9500 / 35.989500 / 35.989500 / 35.98
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)14 / 1315 / 1415 / 14
Minimum weight of rail (calculated) (lb/yd / kg/m)87 / 43.5082 / 4199 / 49.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)54 / 137254 / 137256 / 1422
Boiler Pressure (psi / kPa)200 / 1380200 / 1380210 / 1450
High Pressure Cylinders (dia x stroke) (in / mm)22" x 30" / 559x76222" x 30" / 559x76224" x 32" / 610x813
Low Pressure Cylinders (dia x stroke) (in / mm)35" x 30" / 889x76235" x 30" / 889x76236" x 32" / 914x813
Tractive Effort (lbs / kg)65,531 / 29724.4065,531 / 29724.4081,349 / 36899.33
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.76 4.51 4.39
Heating Ability
Tubes (number - dia) (in / mm)390 - 2.25" / 57207 - 2.25" / 57437 - 2.25" / 57
Flues (number - dia) (in / mm)36 - 5.5" / 140
Flue/Tube length (ft / m)21 / 6.4021 / 6.4021 / 6.40
Firebox Area (sq ft / m2)223.90 / 20.80223 / 20.72264 / 24.53
Grate Area (sq ft / m2)57 / 5.3057 / 5.3078 / 7.25
Evaporative Heating Surface (sq ft / m2)5066 / 470.823855 / 358.275641 / 524.06
Superheating Surface (sq ft / m2)878 / 81.60742 / 68.93
Combined Heating Surface (sq ft / m2)5066 / 470.824733 / 439.876383 / 592.99
Evaporative Heating Surface/Cylinder Volume383.69291.97336.76
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation11,40011,40016,380
Same as above plus superheater percentage11,40013,56618,346
Same as above but substitute firebox area for grate area44,78053,07462,093
Power L1333369367091
Power MT141.31310.38262.89

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