Virginian 2-8-8-8-2/4 "Triplex" Locomotives of the USA

Class Details by Steve Llanso of Sweat House Media

Class XA (Locobase 3301)

Data from DeGolyer, Volume 55, pp. 187+. See also "Triple Articulated Compound Locomotive for the Virginian Railway,", Volume 30, No. 3 (March 1917), pp. 73-76; and "Virginian Railway has World's Greatest Steam Locomotive," Engineering News, Volume 77, No. 11 (15 March 1917), pp 417-418. (Thanks to Peter Christener for his 22 June 2016 email correcting the design's designation and to Chris Hohl's 29 October 2016 email noting the improbable tender capacity Locobase had mistakenly entered.) Baldwin works number was 44448 in November 1916.

Like the Erie's Triplex 2-8-8-8-2s, this single locomotive showed all the limitations of trying to cram so much tractive power under one boiler.

Although this design had slightly smaller cylinders under a slightly larger boiler, the grate and evaporative heating surface were still too small. The small firebox gained some additional direct heating surface from the 72 sq ft (6.7 sq m) in five arch tubes supporting the brick arch. A Gaines type combustion chamber was located ahead of the half-height Gaines wall in the firebox. The firebox's high fuel demand was fed through a Street stoker.

Baldwin feed water heater contained 437 sq ft (40.6 sq m). All six cylinders admitted steam through 14-inch (356 mm) piston valves.

The specifications included the requirement that the engine drag 2,580 tons (2,345 metric tonnes) of cars and leading from Elmore to Clark's Gap over 14 miles (22.5 km) of track of which 12 miles (19.3 km) ascended at 2.07% and wound around ten 12-degree curves. Four-fifths of the load (2,064 tons or 1,876 metric tonnes) were to go up the grade at 10 mph (16 km/h).

Drury (1993) notes that compared to the Erie engines, the 700 "was slower and ran out of steam faster[!]..." He adds that one tunnel had only four inches of clearance, which must have made a passage hell on earth for the locomotive and its crew. "It never made a successful trip," according to Drury.

The engine units were turned into a 2-8-8-0 Mallet (Locobase 3566) and a 2-8-2 Mikado (Locobase 7486), each of which ran until 1953.

Specifications by Steve Llanso of Sweat House Media
Locobase ID3301
RailroadVirginian (VGN)
Number in Class1
Road Numbers700
Number Built1
Valve GearBaker
Locomotive Length and Weight
Driver Wheelbase15.25'
Engine Wheelbase67.58'
Ratio of driving wheelbase to overall engine wheebase 0.23
Overall Wheelbase (engine & tender)91.25'
Axle Loading (Maximum Weight per Axle)62000 lbs
Weight on Drivers725475 lbs
Engine Weight842310 lbs
Tender Light Weight
Total Engine and Tender Weight842310 lbs
Tender Water Capacity13000 gals
Tender Fuel Capacity (oil/coal)12 tons
Minimum weight of rail (calculated)101 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter56"
Boiler Pressure222 psi
High Pressure Cylinders (dia x stroke)34" x 32"
Low Pressure Cylinders (dia x stroke)34" x 32" (4)
Tractive Effort186975 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.88
Heating Ability
Firebox Area431 sq. ft
Grate Area107.60 sq. ft
Evaporative Heating Surface8120 sq. ft
Superheating Surface2059 sq. ft
Combined Heating Surface10179 sq. ft
Evaporative Heating Surface/Cylinder Volume241.47
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation23887
Same as above plus superheater percentage28665
Same as above but substitute firebox area for grate area114818
Power L18875
Power MT323.64



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