Usina Sao Bento 2-4-2 Locomotives in Brazil


Class Details by Steve Llanso of Sweat House Media

Class Hersilia (Locobase 13149)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 30, p. 253. Works number was 31121 in June 1907.

This plantation tank was essentially identical to the engine delivered to the Rio Doce in 1894 (Locobase 12098) although the boiler pressure was up by almost 20%.


Class Ynhata (Locobase 13150)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Vol 30, p. 253 and Vol 44, p. 86, and Vol 66, pp. 345+. Works numbers were 33434 in May 1909, 36755 in August 1911, 47436 in December 1917.

These engines took the basic saddle-tank delivered in 1907 (Locobase 13149) and enlarged its dimensions. The 1911 locomotive was named Paraguassu. The Tymbyra, bought by F Benn & Company for Rocha Lima & Company, was identical to the first two. Baldwin's specification shows 41" drivers, but its own tractive effort calculation uses 42".

Able to burn both coal and wood, these engines were fitted with Radley & Hunter spark-arresting diamond stacks.

Principal Dimensions by Steve Llanso of Sweat House Media

ClassHersiliaYnhata
Locobase ID13149 13150
RailroadUsina Sao BentoUsina Sao Bento
CountryBrazilBrazil
Whyte2-4-2ST2-4-2ST
Number in Class13
Road Numbers
GaugeMetreMetre
Number Built13
BuilderBurnham, Williams & CoBurnham, Williams & Co
Year19071909
Valve GearStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)5 / 1.52 5.67 / 1.73
Engine Wheelbase (ft / m)18.17 / 5.5420 / 6.10
Ratio of driving wheelbase to overall engine wheelbase 0.28 0.28
Overall Wheelbase (engine & tender) (ft / m)18.17 / 5.5420 / 6.10
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)28,000 / 12,70137,000 / 16,783
Engine Weight (lbs / kg)43,000 / 19,50457,000 / 25,855
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)43,000 / 19,50457,000 / 25,855
Tender Water Capacity (gals / ML)600 / 2.27725 / 2.75
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)23 / 11.5031 / 15.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)41 / 104142 / 1067
Boiler Pressure (psi / kPa)150 / 10.30160 / 11
High Pressure Cylinders (dia x stroke) (in / mm)10" x 16" / 254x40612" x 18" / 305x457
Tractive Effort (lbs / kg)4976 / 2257.088393 / 3807.01
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.63 4.41
Heating Ability
Tubes (number - dia) (in / mm)78 - 1.5" / 3891 - 1.75" / 44
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m) 8.11 / 2.47 8.96 / 2.73
Firebox Area (sq ft / m2)46 / 4.2755.30 / 5.14
Grate Area (sq ft / m2)8 / 0.74 8.40 / 0.78
Evaporative Heating Surface (sq ft / m2)295 / 27.41425 / 39.50
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)295 / 27.41425 / 39.50
Evaporative Heating Surface/Cylinder Volume202.83180.38
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation12001344
Same as above plus superheater percentage12001344
Same as above but substitute firebox area for grate area69008848
Power L137003335
Power MT582.65397.43

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