Japanese Government Railways 2-10-4 Locomotives in Japan

Class Details by Steve Llanso of Sweat House Media

Class E10 (Locobase 2493)

Data from Hiroshi Takagi, both from his website ([]) and personal communication August 2000. His indispensable assistance is gratefully acknowledged. Information from Ejii Nozawa's web site ([]) gives number, site, date of construction.

Post-World War II tank engine design that was the only one of its arrangement ever built. The boiler was that of the D51 Mikado with fewer, shorter tubes and a slightly larger grate. The incredibly low factor of adhesion suggests one reason why this engine was not repeated.

Because the measurements above represent the fire side of tubes and flues, a direct comparison with tube & flue heating surface areas of North American and British locomotives requires adding approximately 6-10% to the figures shown.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID2493
RailroadJapanese Government Railways (JGR)
Number in Class5
Road Numbers
Number Built5
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)19.03 / 5.80
Engine Wheelbase (ft / m)38.62 / 11.77
Ratio of driving wheelbase to overall engine wheelbase 0.49
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)31,063 / 14,090
Weight on Drivers (lbs / kg)155,360 / 70,470
Engine Weight (lbs / kg)225,092 / 102,100
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)225,092 / 102,100
Tender Water Capacity (gals / ML)2091 / 7.92
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 4.50 / 4
Minimum weight of rail (calculated) (lb/yd / kg/m)52 / 26
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)49.20 / 1250
Boiler Pressure (psi / kPa)227.70 / 15.70
High Pressure Cylinders (dia x stroke) (in / mm)21.65" x 25.98" / 550x660
Tractive Effort (lbs / kg)47,904 / 21728.91
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.24
Heating Ability
Tubes (number - dia) (in / mm)74 - 2.008" / 51
Flues (number - dia) (in / mm)35 - 5.157" / 131
Flue/Tube length (ft / m)16.40 / 5
Firebox Area (sq ft / m2)154.94 / 14.40
Grate Area (sq ft / m2)35.51 / 3.30
Evaporative Heating Surface (sq ft / m2)1568 / 145.70
Superheating Surface (sq ft / m2)833 / 77.40
Combined Heating Surface (sq ft / m2)2401 / 223.10
Evaporative Heating Surface/Cylinder Volume141.65
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation8086
Same as above plus superheater percentage10,916
Same as above but substitute firebox area for grate area47,628
Power L116,597
Power MT1177.59

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