Data from "New Narrow Gauge Locomotives, Antofagasta Ry" The Locomotive Magazine, Vol XII (15 August 1906), p.137-138.
Hunslet was a pretty constant supplier of locomotives to the Antofagasta, delivering a variety of wheel arrangements to this mountainous skinny-gauge line. These Mikados look relatively austere, but were quite powerful for the gauge in part because the rails they rolled on were relatively heavy.
Data from 1946 Beyer, Peacock catalogue hosted on Martyn Bane's website at [] (accessed 21 May 2006).
A low-drivered Mikado of about average power for the metre gauge.
Data from "General Arrangement Engine-Specification No. 4818-Drc No 2", R&W Hathorn Leslie & Co, Ld; and "Heavy Narrow Gauge Locomotives for the Antofagasta (Chile) & Bolivia Ry" The Locomotive Magazine, Vol XIX (15 March 1913), p.53-54. Additional information from "PULACAYO - Pulacayo 1" website (in Spanish) documenting an old silver mine, last accessed 22 November 2018 at []. Works numbers were 2943-2952 in 1912.
This decade of Mikados put a relatively large boiler and grate on one of the skinniest of gauges. One tradeoff was to accept a relatively low factor of adhesion.
Giorgetta's caption accompanying his photo of a long-abandoned 2-8-2 tells us that the FCAB procured ten of the class. "When the railways between Antofagasta changed the narrow gauge of 2' 6" to metric gauge 1,000 mm, all of these locomotives also were modified for the metre gauge between 1926 and 1928."
Data from "General Arrangement Engine-Specification No. 4818-Drc No 2", R&W Hathorn Leslie & Co, Ld; and Martin Coombs, Chilean steam locomotive list-Part 4- sub-metric gauge locos. v.2.41, October 2020, p. 58 Works numbers were 11891-11900 in 1913.
Coombs reported that these skinny-gauge Mikados "appear to have been built to the same design/drawings as the Hawthorn Leslie 2-8-0s" (Locobase 20104). Like those engines, this entire class was converted to the metric gauge in 1926-1928.
Principal Dimensions by Steve Llanso of Middle Run Media | ||||
---|---|---|---|---|
Class | 75 | unknown | unknown | unknown |
Locobase ID | 10576 | 7495 | 20104 | 20877 |
Railroad | Antofagasta (Chile ) & Bolivia (FCAB) | Antofagasta (Chile ) & Bolivia (FCAB) | Antofagasta (Chile ) & Bolivia (FCAB) | Antofagasta (Chile ) & Bolivia (FCAB) |
Country | Chile | Chile | Chile | Chile |
Whyte | 2-8-2 | 2-8-2 | 2-8-2 | 2-8-2 |
Number in Class | 4 | 3 | 10 | 10 |
Road Numbers | 75-78 | 912 | 161-170 | 171-180 |
Gauge | 2'6" | Metre | 2'6" | 2'6" |
Number Built | 4 | 3 | 10 | 10 |
Builder | Hunslet Engine Co | Beyer, Peacock | Hawthorn Leslie | Henschel & Sohn |
Year | 1906 | 1928 | 1912 | 1913 |
Valve Gear | Walschaert | Walschaert | Walschaert | Walschaert |
Locomotive Length and Weight | ||||
Driver Wheelbase (ft / m) | 10.58 / 3.22 | 11.75 / 3.58 | 10.58 / 3.22 | 10.58 / 3.22 |
Engine Wheelbase (ft / m) | 18 / 5.49 | 26.75 / 8.15 | 24.96 / 7.61 | 24.96 / 7.61 |
Ratio of driving wheelbase to overall engine wheelbase | 0.59 | 0.44 | 0.42 | 0.42 |
Overall Wheelbase (engine & tender) (ft / m) | 42.08 / 12.83 | 47.33 / 14.43 | ||
Axle Loading (Maximum Weight per Axle) (lbs / kg) | 24,640 / 11,177 | 23,604 / 10,707 | 23,604 / 10,707 | |
Weight on Drivers (lbs / kg) | 78,400 / 35,562 | 98,224 / 44,554 | 89,516 / 40,604 | 89,516 / 40,604 |
Engine Weight (lbs / kg) | 89,600 / 40,642 | 135,968 / 61,674 | 111,160 / 50,421 | 111,160 / 50,421 |
Tender Loaded Weight (lbs / kg) | 53,760 / 24,385 | 101,696 / 46,129 | 83,440 / 37,848 | 83,440 / 37,848 |
Total Engine and Tender Weight (lbs / kg) | 143,360 / 65,027 | 237,664 / 107,803 | 194,600 / 88,269 | 194,600 / 88,269 |
Tender Water Capacity (gals / ML) | 2400 / 9.09 | 4200 / 15.91 | 3600 / 13.64 | 3600 / 13.64 |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 7.70 / 7 | 2112 / 7994 | 7.70 / 7 | 7.70 / 7 |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 33 / 16.50 | 41 / 20.50 | 37 / 18.50 | 37 / 18.50 |
Geometry Relating to Tractive Effort | ||||
Driver Diameter (in / mm) | 31.90 / 810 | 42 / 1067 | 37.25 / 946 | 37.25 / 946 |
Boiler Pressure (psi / kPa) | 170 / 1170 | 152.30 / 1050 | 180 / 1240 | 180 / 1240 |
High Pressure Cylinders (dia x stroke) (in / mm) | 15" x 20" / 381x508 | 18" x 24" / 457x610 | 17" x 22" / 432x559 | 17" x 22" / 432x559 |
Tractive Effort (lbs / kg) | 20,384 / 9246.04 | 23,968 / 10871.71 | 26,115 / 11845.58 | 26,115 / 11845.58 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.85 | 4.10 | 3.43 | 3.43 |
Heating Ability | ||||
Tubes (number - dia) (in / mm) | 207 - 1.875" / 48 | 207 - 1.875" / 48 | ||
Flues (number - dia) (in / mm) | ||||
Flue/Tube length (ft / m) | 15 / 4.57 | 15 / 4.57 | ||
Firebox Area (sq ft / m2) | 82 / 7.62 | 94 / 8.74 | 94 / 8.73 | 94 / 8.73 |
Grate Area (sq ft / m2) | 14 / 1.30 | 29.70 / 2.76 | 24.50 / 2.28 | 24.50 / 2.28 |
Evaporative Heating Surface (sq ft / m2) | 1160 / 107.81 | 1694 / 157.43 | 1618 / 150.32 | 1618 / 150.32 |
Superheating Surface (sq ft / m2) | 366 / 34.01 | |||
Combined Heating Surface (sq ft / m2) | 1160 / 107.81 | 2060 / 191.44 | 1618 / 150.32 | 1618 / 150.32 |
Evaporative Heating Surface/Cylinder Volume | 283.58 | 239.65 | 279.95 | 279.95 |
Computations Relating to Power Output (More Information) | ||||
Robert LeMassena's Power Computation | 2380 | 4523 | 4410 | 4410 |
Same as above plus superheater percentage | 2380 | 5338 | 4410 | 4410 |
Same as above but substitute firebox area for grate area | 13,940 | 16,893 | 16,920 | 16,920 |
Power L1 | 3469 | 8232 | 4037 | 4037 |
Power MT | 390.20 | 739.06 | 397.70 | 397.70 |