Erie 2-6-6-4 Locomotives in the USA

Class Details by Steve Llanso of Sweat House Media

Class unknown (Locobase 11024)

Data from Robert LeMassena, "The First 4-8-4 and 2-6+6-4 (almost)", Railway & Locomotive Historical Society Newsletter, Vol 21, No 1 (Winter 2001 ). pp. 4-5.

As Baldwin turned out dozens of the Erie's new 2-8-4 design, which allowed a bigger firebox than the earlier 2-8-2s, it drafted a design for a locomotive that would take that idea even further. And the dimensions and areas of the proposal were simply enormous, later rivalled only by the largest of articulateds.

But the 2-6-6-4 (pace, Mr LeMassena) arrangement never would be popular, mostly because the single-axle leading truck was overmatched by the rest of a very large locomotive. Erie declined to proceed with a prototype and the first 2-6-6-4s would appear five years later on the Pittsburgh & West Virginia (Locobase 301).

Principal Dimensions by Steve Llanso of Sweat House Media
Locobase ID11,024
RailroadErie (proposal)
Number in Class1
Road Numbers
Number Built
Valve GearBaker
Locomotive Length and Weight
Driver Wheelbase (ft / m)12.17 / 3.71
Engine Wheelbase (ft / m)59.08 / 18.01
Ratio of driving wheelbase to overall engine wheebase 0.21
Overall Wheelbase (engine & tender) (ft / m)116.69 / 35.57
Axle Loading (Maximum Weight per Axle) (lbs / kg)72,000 / 32,659
Weight on Drivers (lbs / kg)432,000 / 195,952
Engine Weight (lbs / kg)610,000 / 276,692
Tender Loaded Weight (lbs / kg)413,000 / 187,334
Total Engine and Tender Weight (lbs / kg)1,023,000 / 464,026
Tender Water Capacity (gals / ML)24,000 / 90.91
Tender Fuel Capacity (oil/coal) (gals/tons / ML/MT)30 / 27.30
Minimum weight of rail (calculated) (lb/yd / kg/m)120 / 60
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)70 / 1778
Boiler Pressure (psi / kPa)250 / 17.20
High Pressure Cylinders (dia x stroke) (in / mm)25" x 30" / 635x762 (4)
Tractive Effort (lbs / kg)113,839 / 51636.56
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.79
Heating Ability
Firebox Area (sq ft / m2)680 / 63.20
Grate Area (sq ft / m2)126 / 11.71
Evaporative Heating Surface (sq ft / m2)7100 / 659.85
Superheating Surface (sq ft / m2)3000 / 278.81
Combined Heating Surface (sq ft / m2)10,100 / 938.66
Evaporative Heating Surface/Cylinder Volume208.28
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation31,500
Same as above plus superheater percentage40,950
Same as above but substitute firebox area for grate area221,000
Power L132,086
Power MT982.46

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