Wheeling & Lake Erie 2-6-6-2 "Mallet Mogul" Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class I-2 (Locobase 7895)

Data from W&LE 8 - 1923 & 10 1924 Locomotive Diagram books supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (See also "Mallet Locomotive for the Wheeling & Lake Erie", Railway and Locomotive Engineering, Volume LXXXI [81], No 1 January 1918), p. 4. (Thanks to Chris Hohl for his 4 December 2017 email noting the original tender capacities and weights and the Works numbers were 57043-57052 in April 1917, 57704-57713 in May.

This class owns the distinction of having the biggest-diameter HP and LP cylinders of any 2-6-6-2 Locobase has uncovered. Firebox area was relatively grand as well, the basic hearth heating surface and largest-ever grate augmented by 50 sq ft (4.65 sq m) in five arch tubes. The design also had tall drivers. Each of the four cylinders were fed by 12" (305 mm) piston valves. Although the R&LE report said that the superheater area measured 1,450 sq ft (134.71 sq m), the lower figure shown in the specs was established by the railroad only a few years later.

They were operated on the 80 miles (129 km) of the Toledo division between Pluron, Ohio and Brewster, Ohio where the ruling grade climbed 0.6% over a five-mile climb. The ruling grade is 0.6 per cent, 5 miles (8 km) long. A typical train of 61 loaded cars weighed 4,314 tons. The I-2 averaged 17 mph (27.4 km/h) pulling that train. Delivered with boilers set at 200 psi (13.8 bar), the W&LE soon increased BP to 210 psi.

Eugene Huddleston (Trains, March 1991) tells us that the I-2s were an older design than the USRA Light Mallets that the railroad received just two years later (Locobase 7896). Locobase suspects they were good enough for two decades, although likely to run out of steam on main-line freight runs trying to supply those big HP cylinders, but when the much more up-to-date K-1 2-8-4s (Locobase 64) came on the property in the 1930s, the W&LE shed these compounds quickly. By the end of the 1930s, they had all been scrapped.

Class I-3 (Locobase 7896)

Data from W&LE 8 - 1923 & 10 1924 Locomotive Diagram books supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 58, pp. 173+. Works numbers were 52178, 52265 in August 1919; 52287-52290, 52313, 52330, 52350, 52424 in September.

Compared to the Brooks-built 2-6-6-2s delivered two years earlier (Locobase 7896) these had smaller cylinders and drivers, but larger boilers and more firebox heating surface using longer boiler tubes. The combustion chamber contributed 155 sq ft (14.4 sq m) and 34 sq ft (3.16 sq m) came from five arch tubes. The size of the direct heating components can be judged by the provision of 1,080 flexible staybolts in the combustion chamber water space and the breaking zone of the firebox. All four cylinders used 12" (305 mm) piston valves.

They were in fact USRA Light articulateds, one of that enterprise's less-successful designs that on the W&LE served mine runs out of Pine Valley, Ohio. The original light articulated tender haeld 12,000 US gallons (45,420 litres) of water and 16 tons (14.5 tonnes) of coal; its loaded weight was given as 214,000 lb.

According to Eugene Huddleston (Trains, March 1991, p 37), "No one on the Wheeling ever said the USRA Mallets were a bad design; it was just that a use for them could not be found commensurate with their specifications."

Six were scrapped in the early 1940s. The last four--8001-8003, 8009--remained in service until the 1950s, essentially unchanged. They spent their last days rostered on the Nickel Plate, which had leased the W&LE for 99 years in 1949, and were renumbered 940-943. The 941 retired last on 22 February 1955.

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID7895 7896
RailroadWheeling & Lake ErieWheeling & Lake Erie
Number in Class2010
Road Numbers800-819/8401-84208001-8010/940-943
Number Built2010
Valve GearBakerBaker
Locomotive Length and Weight
Driver Wheelbase (ft / m)11 / 3.3510.60 / 3.23
Engine Wheelbase (ft / m)50.25 / 15.3249.75 / 15.16
Ratio of driving wheelbase to overall engine wheebase 0.22 0.21
Overall Wheelbase (engine & tender) (ft / m)80.05 / 24.4085.04 / 25.92
Axle Loading (Maximum Weight per Axle) (lbs / kg)61,000 / 27,669
Weight on Drivers (lbs / kg)362,500 / 164,427360,000 / 163,293
Engine Weight (lbs / kg)435,000 / 197,313452,000 / 205,024
Tender Loaded Weight (lbs / kg)192,300 / 87,226192,000 / 87,090
Total Engine and Tender Weight (lbs / kg)627,300 / 284,539644,000 / 292,114
Tender Water Capacity (gals / ML)9000 / 34.0910,000 / 37.88
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)23 / 20.9018.50 / 16.80
Minimum weight of rail (calculated) (lb/yd / kg/m)101 / 50.50100 / 50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)63 / 160057 / 1448
Boiler Pressure (psi / kPa)210 / 14.50225 / 15.50
High Pressure Cylinders (dia x stroke) (in / mm)25.5" x 32" / 648x81323" x 32" / 584x813
Low Pressure Cylinders (dia x stroke) (in / mm)39" x 32" / 991x81335" x 32" / 889x813
Tractive Effort (lbs / kg)82,599 / 37466.3279,336 / 35986.25
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.39 4.54
Heating Ability
Firebox Area (sq ft / m2)359.94 / 33.44416 / 38.66
Grate Area (sq ft / m2)99 / 9.2076.30 / 7.09
Evaporative Heating Surface (sq ft / m2)4670 / 433.855443 / 505.86
Superheating Surface (sq ft / m2)1120 / 104.051260 / 117.10
Combined Heating Surface (sq ft / m2)5790 / 537.906703 / 622.96
Evaporative Heating Surface/Cylinder Volume246.89353.72
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation20,79017,168
Same as above plus superheater percentage24,74020,429
Same as above but substitute firebox area for grate area89,949111,384
Power L1824811,315
Power MT300.97415.75

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