Sorocabana 4-8-2 Locomotives in Brazil


Class Details by Steve Llanso of Sweat House Media

Class 801 (Locobase 15395)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University,Volume78, pp. 252+. Works numbers were 59310-59314 in July 1926.

During a brief period in the mid-to-late 1920s, both Alco and Baldwin offered three-cylinder engines for all sizes of gauge. This quintet of bi-fuel (Cardiff coal or wood) passenger Mountains were among the biggest of their wheel arrangement to be built for the metre gauge. They operated on 65 lb/yard (32.5 kg/metre) rail up 2 1/2% grades that included 13.4 degree curves (radii of 130 metres ).

For all their size, their fireboxes seem small and indeed the design contains an imbalance between the size of the boiler and the cylinder volume and a relatively small firebox and a low factor of adhesion. The nearly square cylinders were supplied superheater steam through three 10" (254 mm) piston valves. Usually, these engines burned coal, but they were to accept "readily" a change to wood fuel.

Their green paint was very precisely formulated: 7,200 grams (15.87 lb) of canary yellow, 1,200 grams (2.65 lb) of ivory black (an oddly self-contradictory designation), and 200 grams (7.05 ounces) of chinese vermillion. The first coat was to be "very dry", the second "brilliant" and covered by two coats of varnish.


Class 806 (Locobase 20972)

Data from , p. 978. Works numbers were 66979-66983 in August 1926, 67400-67409 in May 1927.

A year and a half after Baldwin delivered five metre-gauge Mountains to the Sorocabana (Locobase 15395), Alco's Schenectady supplied fifteen more of approximately the same design. As the specs show, however, the Alcos used three smaller-diameter pistons and varied the stroke lengths depending on whether the cylinders were outside (24") or inside (22"). Calculated tractive effort remained about the same as the smaller drivers (48" vs 54") compensated for the smaller piston area in the cylinders.

Principal Dimensions by Steve Llanso of Middle Run Media
Class801806
Locobase ID15395 20972
RailroadSorocabanaSorocabana
CountryBrazilBrazil
Whyte4-8-24-8-2
Number in Class515
Road Numbers801-805806-820
GaugeMetreMetre
Number Built515
BuilderBaldwinAlco-Schenectady
Year19261924
Valve GearWalschaertBaker
Locomotive Length and Weight
Driver Wheelbase (ft / m)15 / 4.57
Engine Wheelbase (ft / m)34.17 / 10.42
Ratio of driving wheelbase to overall engine wheelbase 0.44
Overall Wheelbase (engine & tender) (ft / m)60.54 / 18.45
Axle Loading (Maximum Weight per Axle) (lbs / kg)35,265 / 15,996
Weight on Drivers (lbs / kg)141,000 / 63,957137,500 / 62,369
Engine Weight (lbs / kg)207,000 / 93,894199,000 / 90,265
Tender Loaded Weight (lbs / kg)81,000 / 36,741
Total Engine and Tender Weight (lbs / kg)288,000 / 130,635
Tender Water Capacity (gals / ML)3700 / 14.02
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)8 / 7
Minimum weight of rail (calculated) (lb/yd / kg/m)59 / 29.5057 / 28.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)54 / 137248 / 1219
Boiler Pressure (psi / kPa)202 / 1390200 / 1380
High Pressure Cylinders (dia x stroke) (in / mm)20" x 22" / 508x559 (3)18.5" x 24" / 470x610
Low Pressure Cylinders (dia x stroke) (in / mm)18.5" x 22" / 470x559 (1)
Tractive Effort (lbs / kg)41,971 / 19037.7542,424 / 19243.23
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.36 3.24
Heating Ability
Tubes (number - dia) (in / mm)157 - 2.25" / 57
Flues (number - dia) (in / mm)34 - 5.5" / 140
Flue/Tube length (ft / m)20.75 / 6.32
Firebox Area (sq ft / m2)165 / 15.33173 / 16.07
Grate Area (sq ft / m2)52.20 / 4.8549.20 / 4.57
Evaporative Heating Surface (sq ft / m2)3088 / 286.883179 / 295.34
Superheating Surface (sq ft / m2)863 / 80.17856 / 79.52
Combined Heating Surface (sq ft / m2)3951 / 367.054035 / 374.86
Evaporative Heating Surface/Cylinder Volume257.35425.75
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation10,5449840
Same as above plus superheater percentage12,86411,906
Same as above but substitute firebox area for grate area40,66341,866
Power L117,69617,262
Power MT1106.751107.09

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