Araraquara 4-8-0 Locomotives in Brazil


Class Details by Steve Llanso of Sweat House Media

Class 21 (Locobase 20543)

Data from Lionel Wiener, "Les Chemins de Fer de Bresil", Revue General (Janvier 1923), p. 13. Works numbers were 8110-8111 and 8498-8503 in 1912

A photo of this design shows two outsized domes on a straight boiler. For some reason, D R Carling's definitive book on Twelve-wheeled engines doesn't mention this batch.


Class 6 (Locobase 13145)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 30, p. 242 and .Volume 33, p. 30; and Walter Camp, "Recent Baldwin Locomotives for Foreign Shipment", Railway and Engineering Review, Volume XLVII [47], No 39 (28 September 1907), p. 846 See Locobase 13144 for a brief description of the Araraquara. Works numbers were 31064 in June 1907 and 34160 in January 1910.

Dennis Rock Carling's 1972 history of the 4-8-0 arrangement doesn't include this pair of narrow-gauge, wood-burning Twelve-wheelers. The 1907 engine was procured through the Schill Seebohm & Company trading company. Baldwin's specs indicated the demands imposed by the 6's operating environment when they required the 6 to ascend a maximum grade of 2 1/2% while hauling 175 tons, negotiate a curve radius of 120 metres (394 ft or 9 1/2 degrees), and pull 1,450 tons on the level while not overburdening the 38-40-lb/yard (19-20-kg/metre) rail.

The design's cylinders sloped at 1:48 toward the front to clear the four-wheel bogies. Continuously equalized on each side, the driver set included flangeless second and third drivers on each side to aid in negotiating sharp curves. Cast steel frames joined with doubled wrought iron in the front frames. A 16" (406 mm) straight stack rose out of its extended smokebox. (Many narrow-gauge wood-burners used a large cinder-catching stack, but perhaps the Araraquara's operating area didn't include much forest along the tracks.)

To extend the locomotive's range, the tender on the 6 featured a wood rack that stood 3' (914 mm) above the sides and 12" (305 mm) along each side; its rated capacity was two cords.. When Araraquara ordered its twin two years later, however, they changed the spec to eliminate the side boards. (Locobase wonders if they made loading the tender--presumably by hand--more difficult.)

Principal Dimensions by Steve Llanso of Middle Run Media
Class216
Locobase ID20543 13145
RailroadAraraquaraAraraquara
CountryBrazilBrazil
Whyte4-8-04-8-0
Number in Class2
Road Numbers21-266, 13
GaugeMetreMetre
Number Built2
BuilderBorsigBurnham, Williams & Co
Year19121907
Valve GearStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)11.48 / 3.5011.75 / 3.58
Engine Wheelbase (ft / m)19.77 / 6.0320.42 / 6.22
Ratio of driving wheelbase to overall engine wheelbase 0.58 0.58
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)59,525 / 27,00066,000 / 29,937
Engine Weight (lbs / kg)78,264 / 35,50081,000 / 36,741
Tender Loaded Weight (lbs / kg)66,139 / 30,00050,000 / 22,680
Total Engine and Tender Weight (lbs / kg)144,403 / 65,500131,000 / 59,421
Tender Water Capacity (gals / ML)2244 / 8.502500 / 9.47
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)11.60 / 11
Minimum weight of rail (calculated) (lb/yd / kg/m)25 / 12.5028 / 14
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)38 / 96538 / 965
Boiler Pressure (psi / kPa)171.10 / 1180160 / 1100
High Pressure Cylinders (dia x stroke) (in / mm)16.14" x 20.08" / 410x51016" x 20" / 406x508
Tractive Effort (lbs / kg)20,020 / 9080.9318,324 / 8311.64
Factor of Adhesion (Weight on Drivers/Tractive Effort) 2.97 3.60
Heating Ability
Tubes (number - dia) (in / mm)150 - 2" / 51
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)13.54 / 4.13
Firebox Area (sq ft / m2)88.30 / 8.21
Grate Area (sq ft / m2)19.38 / 1.8015.40 / 1.43
Evaporative Heating Surface (sq ft / m2)1098 / 1021138 / 105.76
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1098 / 1021138 / 105.76
Evaporative Heating Surface/Cylinder Volume230.92244.51
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation33162464
Same as above plus superheater percentage33162464
Same as above but substitute firebox area for grate area14,128
Power L13439
Power MT459.50

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