Centro-Oeste 4-6-2 Locomotives in Brazil


Class Details by Steve Llanso of Sweat House Media

Class 339 (Locobase 14514)

Data from 40-RMV-4-6-2-N340.gif, archived at [] (Thanks to Teemu Koivumaki whose 2023 email included a comprehensive spreadsheet of Brazilian steam locomotive builders, works numbers, and owners.)

According to the Centro-Oeste website, the two home-built locomotives came out of the Diviinopolis workshops despite the warning of the Chief Mechanic Joao Morato de Faria that the plan "will not work!" The "plan"was to work around serious supply-chain problems secuing machines and spare parts and turn out domestic designs in short order.. And, says the account, "he was right". As Google translates the account:

"The warning was not considered and the original project was maintained. In 60 days, the locomotive was ready, and it was a total fiasco: - Even without the weight of the tender, it couldn't even move itself."

Fortunately for the railway , the administration conceded Morato's point and put him in charge of revising the desgin, giving him "carte blanche, material, and the companions he chose, to see what he could achieve."

He rewarded their trust by delivering a worthy upgrade of the trial-horse 339. The pair served passenger trains in southern and western Minas Gerais until the 339's crew exploded becasue of operator error. 340 continued on until 1965 when it was withdrawn. It wound up on display in front of its original workshop.

NB: The figure for the number of 2" tubes in the diagram for this dual-fuel Pacific is clearly typed "97", yet that results in a tube heating surface area of 73 sq m (786 sq ft). The value given in the diagram for tube heating surface area is 103.85 sq m (1,118 sq ft), a 42% difference. Moreover, there is no sign of a superheater. Locobase found that 137 tubes resolved the difference, but he cannot explain it.

Principal Dimensions by Steve Llanso of Sweat House Media

Class339
Locobase ID14514
RailroadCentro-Oeste
CountryBrazil
Whyte4-6-2
Number in Class2
Road Numbers339-340
GaugeMetre
Number Built2
BuilderRMV
Year1941
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m) 8.50 / 2.59
Engine Wheelbase (ft / m)24.14 / 7.36
Ratio of driving wheelbase to overall engine wheelbase 0.35
Overall Wheelbase (engine & tender) (ft / m)51.41 / 15.67
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)72,752 / 33,000
Engine Weight (lbs / kg)94,799 / 43,000
Tender Loaded Weight (lbs / kg)71,209 / 32,300
Total Engine and Tender Weight (lbs / kg)166,008 / 75,300
Tender Water Capacity (gals / ML)6418 / 24.31
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)77 / 291
Minimum weight of rail (calculated) (lb/yd / kg/m)40 / 20
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)45.70 / 1161
Boiler Pressure (psi / kPa)179.80 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)13.27" x 19.96" / 337x507
Tractive Effort (lbs / kg)11,754 / 5331.53
Factor of Adhesion (Weight on Drivers/Tractive Effort) 6.19
Heating Ability
Tubes (number - dia) (in / mm)137 - 2.008" / 51
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)15.42 / 4.70
Firebox Area (sq ft / m2)114.53 / 10.64
Grate Area (sq ft / m2)22.28 / 2.07
Evaporative Heating Surface (sq ft / m2)1232 / 114.50
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1232 / 114.50
Evaporative Heating Surface/Cylinder Volume385.60
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation4006
Same as above plus superheater percentage4006
Same as above but substitute firebox area for grate area20,592
Power L17735
Power MT703.19

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