Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 49, p. 208. For a general history of Japanese light railways, see Eiichi Aoki, "Construction of Local Railways," Japanese Railway History 5 (July 1995), pp. 34-37, archived at [] . Works numbers were 38851-38853 in November 1912 and 38921-38923 in December.
Locomotive brokers Frazer & Company negotiated the purchase of this half-dozen Eight-wheelers, which equipped one of the first light railways built under the Light Railway Act ("enforced" 3 August 1910 and its corollary, the Light Railway Subsidy Act of 1 January 1912. The level of construction approved under these programs was deliberately scaled to require less infrastructure than the JNR level of service, but more than the tramways, which were seen as too light and unsafe in populated areas. The first president of Japan's Railway Bureau, Goto Shinpei, was most interested in promoting trunk line growth and saw the light-railway program as a way to satisfy a pressing demand relatively inexpensively.
Perhaps the key feature of these light railways (keiben tetsudo) was their local character. Individual communities formed local railway societies that raised capital, often accumulated through many small donations, to build feeder liners that linked the town or small city with the national railway network. Because even the lightly built lines that resulted often required more financing than the communities' could muster, the Subsidy Act allowed government support.
Principal Dimensions by Steve Llanso of Middle Run Media | |
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Class | 20 |
Locobase ID | 14223 |
Railroad | Tobu Steam Light Railway |
Country | Japan |
Whyte | 4-4-0 |
Number in Class | 6 |
Road Numbers | 20-25 |
Gauge | 3'6" |
Number Built | 6 |
Builder | Baldwin |
Year | 1912 |
Valve Gear | Stephenson |
Locomotive Length and Weight | |
Driver Wheelbase (ft / m) | 6.83 / 2.08 |
Engine Wheelbase (ft / m) | 19.83 / 6.04 |
Ratio of driving wheelbase to overall engine wheelbase | 0.34 |
Overall Wheelbase (engine & tender) (ft / m) | 38.83 / 11.84 |
Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
Weight on Drivers (lbs / kg) | 52,000 / 23,587 |
Engine Weight (lbs / kg) | 73,000 / 33,112 |
Tender Loaded Weight (lbs / kg) | 55,000 / 24,948 |
Total Engine and Tender Weight (lbs / kg) | 128,000 / 58,060 |
Tender Water Capacity (gals / ML) | 2760 / 10.45 |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 3 / 3 |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 43 / 21.50 |
Geometry Relating to Tractive Effort | |
Driver Diameter (in / mm) | 60 / 1524 |
Boiler Pressure (psi / kPa) | 180 / 1240 |
High Pressure Cylinders (dia x stroke) (in / mm) | 15" x 22" / 381x559 |
Tractive Effort (lbs / kg) | 12,623 / 5725.70 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.12 |
Heating Ability | |
Tubes (number - dia) (in / mm) | 155 - 2" / 51 |
Flues (number - dia) (in / mm) | |
Flue/Tube length (ft / m) | 10.50 / 3.20 |
Firebox Area (sq ft / m2) | 98 / 9.10 |
Grate Area (sq ft / m2) | 17 / 1.58 |
Evaporative Heating Surface (sq ft / m2) | 943 / 87.61 |
Superheating Surface (sq ft / m2) | |
Combined Heating Surface (sq ft / m2) | 943 / 87.61 |
Evaporative Heating Surface/Cylinder Volume | 209.57 |
Computations Relating to Power Output (More Information) | |
Robert LeMassena's Power Computation | 3060 |
Same as above plus superheater percentage | 3060 |
Same as above but substitute firebox area for grate area | 17,640 |
Power L1 | 5732 |
Power MT | 486.03 |