Data from FC CC de Bolivia 1958 Locomotive Diagrams, supplied in August 2022 by Allen Stanley from his extensive Railroad Data Exchange collection.
Locobase noted the relatively mammoth dimensions of this metre-gauge Mikado design in its saturated-boiler version (Locobase 21077). He also noted that the ratio between evaporative heating surface area and cylinder volume seemed very high. FCB's shops modified the pair in 1939, increasing the cylinder diameters and adding a superheater to generate hotter, drier steam.
Tradeoffs included a slight reduction in combined heating surface area and greater weight. Valve gear, wheelbases, and firebox remained unchanged.
Data from FC de Bolivia 11 - 1918 Locomotive and Car Diagrams and FC CC de Bolivia 1958 Locomotive Diagrams, both supplied in August 2022 by Allen Stanley from his extensive Railroad Data Exchange collection. Works numbers were 4860-4861 in 1912.
In his compilation of 52 different Mikados for the metre gauge, Locobase hasn't met one that had as much heating surface area as these two Leeds-built engines. They fell in the top quarter of engine weight. But its heating surface to cylinder volume ratio of 374:1 also topped the charts, suggesting that the design was either over-boilered and under-cylindered.
Apparently the FCB agreed and the superheated, upgraded 409-410 were the result; see Locobase 21078.
Principal Dimensions by Steve Llanso of Middle Run Media | ||
---|---|---|
Class | 409 | 601/409 |
Locobase ID | 21078 | 21077 |
Railroad | Bolivia | Bolivia |
Country | Bolivia | Bolivia |
Whyte | 2-8-2 | 2-8-2 |
Number in Class | 2 | 2 |
Road Numbers | 409-410 | 601-602/409-410 |
Gauge | Metre | Metre |
Number Built | 2 | |
Builder | Kitson & Co | Kitson & Co |
Year | 1939 | 1912 |
Valve Gear | Walschaert | Walschaert |
Locomotive Length and Weight | ||
Driver Wheelbase (ft / m) | 11.75 / 3.58 | 11.75 / 3.58 |
Engine Wheelbase (ft / m) | 26.57 / 8.10 | 26.58 / 8.10 |
Ratio of driving wheelbase to overall engine wheelbase | 0.44 | 0.44 |
Overall Wheelbase (engine & tender) (ft / m) | 56.76 / 17.30 | 56.75 / 17.30 |
Axle Loading (Maximum Weight per Axle) (lbs / kg) | 32,364 / 14,680 | 23,604 / 10,707 |
Weight on Drivers (lbs / kg) | 123,856 / 56,180 | 100,912 / 45,773 |
Engine Weight (lbs / kg) | 167,088 / 75,790 | 161,728 / 73,359 |
Tender Loaded Weight (lbs / kg) | 120,945 / 54,860 | 117,264 / 53,190 |
Total Engine and Tender Weight (lbs / kg) | 288,033 / 130,650 | 278,992 / 126,549 |
Tender Water Capacity (gals / ML) | 5394 / 20.43 | 3326 / 12.60 |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 2166 / 8200 | 4.40 / 4 |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 52 / 26 | 42 / 21 |
Geometry Relating to Tractive Effort | ||
Driver Diameter (in / mm) | 44 / 1118 | 44 / 1118 |
Boiler Pressure (psi / kPa) | 174 / 1200 | 180 / 1240 |
High Pressure Cylinders (dia x stroke) (in / mm) | 20.98" x 24.02" / 533x610 | 19" x 24" / 483x610 |
Tractive Effort (lbs / kg) | 35,539 / 16120.24 | 30,127 / 13665.39 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.49 | 3.35 |
Heating Ability | ||
Tubes (number - dia) (in / mm) | 202 - 1.89" / 48 | 379 - 1.875" / 48 |
Flues (number - dia) (in / mm) | 30 - 5.236" / 133 | |
Flue/Tube length (ft / m) | 14.99 / 4.57 | 15 / 4.57 |
Firebox Area (sq ft / m2) | 154.03 / 14.31 | 154 / 14.31 |
Grate Area (sq ft / m2) | 40.15 / 3.73 | 40.25 / 3.74 |
Evaporative Heating Surface (sq ft / m2) | 2255 / 209.50 | 2945 / 273.60 |
Superheating Surface (sq ft / m2) | 492 / 45.71 | |
Combined Heating Surface (sq ft / m2) | 2747 / 255.21 | 2945 / 273.60 |
Evaporative Heating Surface/Cylinder Volume | 234.63 | 373.93 |
Computations Relating to Power Output (More Information) | ||
Robert LeMassena's Power Computation | 6986 | 7245 |
Same as above plus superheater percentage | 8244 | 7245 |
Same as above but substitute firebox area for grate area | 31,625 | 27,720 |
Power L1 | 9895 | 6226 |
Power MT | 704.52 | 544.08 |