Sorocabana 4-10-2 Locomotives in Brazil


Class Details by Steve Llanso of Sweat House Media

Class 1001 (Locobase 4421)

Data from Bruce Pryor, Locomotives, 4-10-2 on the Narrow Gauge Pictures From Off The Beaten Path at [], last accessed 3 April 2023; Alco-Schenectady builder's card for Order No. S-1742 for Class 4102 S 235 "Three Cylinder" supplied by Alexander Blessing in his 2 April 2023 email (Locobase thanks Alex for the information.). Works numbers were 67996-68000 in July 1929, 68694-68697 in April 1935

Only a few dozen 4-10-2 three-cylinder locomotives entered service on United States railroads. Alco did enjoy some ezport success that included these metre-gauge engines. There were at least two batches of 4-10-2s built for the Sorocabana, this design and the later one found under Locobase 975.

The data imply a well-balanced design that featured a high percentage of superheater area, sizable grate burning "Cardiff coal" and firebox heating surface areas. Its factor of adhesion suggests good traction as well.


Class 1015 (Locobase 975)

Data from 1947 Locomotive Cyclopedia. Works numbers were 69137-69140 in March 1939, 69250-69253 in February 1940

Stroke was actually 22" for the inside cylinder, 24" for the two outside cylinders. This design appears to be an elaboration of Henschel's Mikado of 1930, but with an additional leading truck axle.

Principal Dimensions by Steve Llanso of Sweat House Media

Class10011015
Locobase ID4421 975
RailroadSorocabanaSorocabana
CountryBrazilBrazil
Whyte4-10-24-10-2
Number in Class98
Road Numbers1001-10091015-1022
Gaugemetremetre
Number Built98
BuilderAlco-SchenectadyAlco-Schenectady
Year19291940
Valve GearWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)19.08 / 5.8219.08 / 5.82
Engine Wheelbase (ft / m)37.75 / 11.5138.58 / 11.76
Ratio of driving wheelbase to overall engine wheelbase 0.51 0.49
Overall Wheelbase (engine & tender) (ft / m)63.87 / 19.47
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)178,000 / 80,740187,340 / 84,976
Engine Weight (lbs / kg)234,500 / 106,368250,000 / 113,398
Tender Loaded Weight (lbs / kg)93,000 / 42,184245,000 / 111,130
Total Engine and Tender Weight (lbs / kg)327,500 / 148,552495,000 / 224,528
Tender Water Capacity (gals / ML)4500 / 17.05
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)7 / 6.40
Minimum weight of rail (calculated) (lb/yd / kg/m)59 / 29.5062 / 31
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)48 / 121948 / 1219
Boiler Pressure (psi / kPa)210 / 14.50239.30 / 16.50
High Pressure Cylinders (dia x stroke) (in / mm)18.5" x 24" / 470x610 (1)17.5" x 24" / 445x610
Low Pressure Cylinders (dia x stroke) (in / mm)18.5" x 22" / 470x55917.5" x 22" / 445x559 (1)
Tractive Effort (lbs / kg)43,273 / 19628.3345,421 / 20602.64
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.11 4.12
Heating Ability
Tubes (number - dia) (in / mm)210 - 2" / 51
Flues (number - dia) (in / mm)38 - 5.375" / 137
Flue/Tube length (ft / m)18.50 / 5.64
Firebox Area (sq ft / m2)253 / 23.50
Grate Area (sq ft / m2)55.50 / 5.1665.30 / 6.07
Evaporative Heating Surface (sq ft / m2)3261 / 302.963346 / 310.97
Superheating Surface (sq ft / m2)857 / 79.62851 / 79.09
Combined Heating Surface (sq ft / m2)4118 / 382.584197 / 390.06
Evaporative Heating Surface/Cylinder Volume873.47500.80
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation11,65515,626
Same as above plus superheater percentage14,10318,752
Same as above but substitute firebox area for grate area64,287
Power L119,438
Power MT1203.75

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