Antofagasta 2-8-2 Locomotives in Chile


Class Details by Steve Llanso of Sweat House Media

Class 75 (Locobase 10576)

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.


Class unknown (Locobase 7495)

Data from 1946 Beyer, Peacock catalogue hosted on Martyn Bane's website at [link] (accessed 21 May 2006).

A low-drivered Mikado of about average power for the metre gauge.


Class unknown (Locobase 20104)

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 [link]. 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."


Class unknown (Locobase 20877)

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
Class75unknownunknownunknown
Locobase ID10576 7495 20104 20877
RailroadAntofagasta (Chile ) & Bolivia (FCAB)Antofagasta (Chile ) & Bolivia (FCAB)Antofagasta (Chile ) & Bolivia (FCAB)Antofagasta (Chile ) & Bolivia (FCAB)
CountryChileChileChileChile
Whyte2-8-22-8-22-8-22-8-2
Number in Class431010
Road Numbers75-78912161-170171-180
Gauge2'6"Metre2'6"2'6"
Number Built431010
BuilderHunslet Engine CoBeyer, PeacockHawthorn LeslieHenschel & Sohn
Year1906192819121913
Valve GearWalschaertWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)10.58 / 3.2211.75 / 3.5810.58 / 3.2210.58 / 3.22
Engine Wheelbase (ft / m)18 / 5.4926.75 / 8.1524.96 / 7.6124.96 / 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 / 12.8347.33 / 14.43
Axle Loading (Maximum Weight per Axle) (lbs / kg)24,640 / 11,17723,604 / 10,70723,604 / 10,707
Weight on Drivers (lbs / kg)78,400 / 35,56298,224 / 44,55489,516 / 40,60489,516 / 40,604
Engine Weight (lbs / kg)89,600 / 40,642135,968 / 61,674111,160 / 50,421111,160 / 50,421
Tender Loaded Weight (lbs / kg)53,760 / 24,385101,696 / 46,12983,440 / 37,84883,440 / 37,848
Total Engine and Tender Weight (lbs / kg)143,360 / 65,027237,664 / 107,803194,600 / 88,269194,600 / 88,269
Tender Water Capacity (gals / ML)2400 / 9.094200 / 15.913600 / 13.643600 / 13.64
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 7.70 / 72112 / 7994 7.70 / 7 7.70 / 7
Minimum weight of rail (calculated) (lb/yd / kg/m)33 / 16.5041 / 20.5037 / 18.5037 / 18.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)31.90 / 81042 / 106737.25 / 94637.25 / 946
Boiler Pressure (psi / kPa)170 / 1170152.30 / 1050180 / 1240180 / 1240
High Pressure Cylinders (dia x stroke) (in / mm)15" x 20" / 381x50818" x 24" / 457x61017" x 22" / 432x55917" x 22" / 432x559
Tractive Effort (lbs / kg)20,384 / 9246.0423,968 / 10871.7126,115 / 11845.5826,115 / 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" / 48207 - 1.875" / 48
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)15 / 4.5715 / 4.57
Firebox Area (sq ft / m2)82 / 7.6294 / 8.7494 / 8.7394 / 8.73
Grate Area (sq ft / m2)14 / 1.3029.70 / 2.7624.50 / 2.2824.50 / 2.28
Evaporative Heating Surface (sq ft / m2)1160 / 107.811694 / 157.431618 / 150.321618 / 150.32
Superheating Surface (sq ft / m2)366 / 34.01
Combined Heating Surface (sq ft / m2)1160 / 107.812060 / 191.441618 / 150.321618 / 150.32
Evaporative Heating Surface/Cylinder Volume283.58239.65279.95279.95
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2380452344104410
Same as above plus superheater percentage2380533844104410
Same as above but substitute firebox area for grate area13,94016,89316,92016,920
Power L13469823240374037
Power MT390.20739.06397.70397.70

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