Data from Hiroshi Takagi, both from his website ([]) and personal communication August 2000. His indispensable assistance is gratefully acknowledged.
Note that when the 8700s (Locobase 3806) were superheated, they received larger pistons as well, which increased tractive effort. Note too how many fewer tubes the boiler had when space was made for the large superheater flues.
Data from Hiroshi Takagi, both from his website ([]) and personal communication August 2000. His indispensable assistance is gratefully acknowledged.
When the 8800s were retubed, they mirrored what seems to have been standard Japanese practice by emphasizing the flue area at the expense of tube cross-section. Also, notice the big increase in the weights. One wonders if this was a very successful design or did the weight growth reflect a lack of control of detail design.
Data from Hiroshi Takagi, both from his website ([]) and personal communication August 2000. His indispensable assistance is gratefully acknowledged.
Retubed 8850s (Locobase 3810) with more, smaller flues and fewer tubes.
Principal Dimensions by Steve Llanso of Middle Run Media | |||
---|---|---|---|
Class | 8700 - superheated | 8800 -- retubed | 8850 - refitted |
Locobase ID | 3807 | 3809 | 3811 |
Railroad | Japanese National Railways (JNR) | Japanese National Railways (JNR) | Japanese National Railways (JNR) |
Country | Japan | Japan | Japan |
Whyte | 4-6-0 | 4-6-0 | 4-6-0 |
Number in Class | |||
Road Numbers | 8850 | ||
Gauge | 3'6" | 3'6" | 3'6" |
Number Built | |||
Builder | |||
Year | |||
Valve Gear | Walschaert | Walschaert | Walschaert |
Locomotive Length and Weight | |||
Driver Wheelbase (ft / m) | 13.48 / 4.11 | 13.75 / 4.19 | 12.01 / 3.66 |
Engine Wheelbase (ft / m) | 25.50 / 7.77 | / 7.88 | |
Ratio of driving wheelbase to overall engine wheelbase | 0.54 | ||
Overall Wheelbase (engine & tender) (ft / m) | 47.46 / 14.47 | / 14.60 | |
Axle Loading (Maximum Weight per Axle) (lbs / kg) | 27,844 / 12,630 | 29,520 / 13,390 | 29,674 / 13,460 |
Weight on Drivers (lbs / kg) | 83,533 / 37,890 | 88,538 / 40,160 | 89,023 / 40,380 |
Engine Weight (lbs / kg) | 113,362 / 51,420 | 118,785 / 53,880 | 126,854 / 57,540 |
Tender Loaded Weight (lbs / kg) | / 29,450 | ||
Total Engine and Tender Weight (lbs / kg) | / 86,990 | ||
Tender Water Capacity (gals / ML) | |||
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | |||
Minimum weight of rail (calculated) (lb/yd / kg/m) | 46 / 23 | 49 / 24.50 | 49 / 24.50 |
Geometry Relating to Tractive Effort | |||
Driver Diameter (in / mm) | 63 / 1600 | 63 / 1600 | 63 / 1600 |
Boiler Pressure (psi / kPa) | 184.20 / 1270 | 185 / 1280 | 185.60 / 1280 |
High Pressure Cylinders (dia x stroke) (in / mm) | 18.5" x 24.02" / 470x610 | 18.5" x 24" / 470x610 | 18.5" x 24.02" / 470x610 |
Tractive Effort (lbs / kg) | 20,431 / 9267.36 | 20,502 / 9299.56 | 20,586 / 9337.66 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.09 | 4.32 | 4.32 |
Heating Ability | |||
Tubes (number - dia) (in / mm) | 79 - 2.008" / 51 | 66 - 2" / 51 | 66 - 2.244" / 57 |
Flues (number - dia) (in / mm) | 22 - 5.236" / 133 | 19 - 5.25" / 133 | 19 - 5" / 127 |
Flue/Tube length (ft / m) | 13.48 / 4.11 | 15 / 4.57 | 14.99 / 4.57 |
Firebox Area (sq ft / m2) | 125.89 / 11.70 | 126.97 / 11.80 | 123.52 / 11.48 |
Grate Area (sq ft / m2) | 20.01 / 1.86 | 20.01 / 1.86 | 19.48 / 1.81 |
Evaporative Heating Surface (sq ft / m2) | 1081 / 100.50 | 1099 / 102.10 | 1096 / 101.82 |
Superheating Surface (sq ft / m2) | 363 / 33.70 | 368 / 34.19 | 368 / 34.18 |
Combined Heating Surface (sq ft / m2) | 1444 / 134.20 | 1467 / 136.29 | 1464 / 136 |
Evaporative Heating Surface/Cylinder Volume | 144.65 | 147.19 | 146.66 |
Computations Relating to Power Output (More Information) | |||
Robert LeMassena's Power Computation | 3686 | 3702 | 3615 |
Same as above plus superheater percentage | 4607 | 4627 | 4519 |
Same as above but substitute firebox area for grate area | 28,986 | 29,362 | 28,657 |
Power L1 | 12,882 | 13,127 | 13,106 |
Power MT | 1019.95 | 980.60 | 973.69 |