Oeste de Minas 4-6-2 Locomotives in Brazil


Class Details by Steve Llanso of Sweat House Media

Class 163 (Locobase 15392)

Data from narrowmind.railfan.net, supplemented and corrected by DeGolyer, Vol 78, pp. 225+. Works numbers were 58851 in November 1925; 58852, 58879-58882 in December 1925.

A sextet of passenger Pacifics with good power for the metre gauge. The big grate was needed to burn the low-calorie Brazilian coal and the firebox's heating surface was supplemented by 16 sq ft (1.5 sq m) of arch tubes. Superheated steam was admitted to the cylinders through 8" (203 mm) piston valves.

All would later operate on the Santa Catarina, which was rolled into the Rede Mineira de Viatpo (RMV). At least the 335 continued in tourist service after the end of the Second Millennium.


Class 169 (Locobase 15391)

Data from narrowmind.railfan.net, supplemented and corrected by DeGolyer, Volume78, pp. 225+. Works numbers were 58883-58884 in December 1925.

Note this is a compact, three-cylinder freight engine burning Brazilian coal (hence the low grate demand factor). Six axles (vs the five of a 4-6-0 or 2-8-0) spread the weight out while the three cylinders (fed by small 6"/152 mm piston valves) must have smoothed out the power. In all other respects, the 169 and 170 were identical to the six passenger engines purchased at nearly the same time (see Locobase 15392).

This pair would later operate on the Santa Catarina, which was rolled into the Rede Mineira de Viatpo (RMV). Even after the turn into the Twenty-First century, the 338 could still be found in tourist service on the former Mogyana Railway.


Class 80 (Locobase 13254)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 44, p. 53. Works numbers were 37829-37837 in July 1912.


Class 89 (Locobase 15120)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 66, p. 249. Works numbers were 52410-52413 in September 1919.

The Oeste de Minas returned to Baldwin for more Pacifics seven years after the earlier set was delivered (Locob ase 13254). Like the older engines, these were superheated wood-burners with the same power dimensions and firebox. But the boiler layout was reorganized to accommodate more Type A elements in slightly smaller flues. Some small tubes were inevitably sacrificed to make room.

The result was a greater percentage of heating surface being derived from the superheater.

Principal Dimensions by Steve Llanso of Middle Run Media
Class1631698089
Locobase ID15392 15391 13254 15120
RailroadOeste de MinasOeste de MinasOeste de MinasOeste de Minas
CountryBrazilBrazilBrazilBrazil
Whyte4-6-24-6-24-6-24-6-2
Number in Class6294
Road Numbers163-168 / 331-336169-170 / 337-33880-8889-92
GaugemetremetreMetreMetre
Number Built6294
BuilderBaldwinBaldwinBaldwinBaldwin
Year1925192519121919
Valve GearWalschaertWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m) 8.83 / 2.69 8.83 / 2.69 8.50 / 2.59 8.50 / 2.59
Engine Wheelbase (ft / m)24.67 / 7.5224.67 / 7.5224 / 7.3224 / 7.32
Ratio of driving wheelbase to overall engine wheelbase 0.36 0.36 0.35 0.35
Overall Wheelbase (engine & tender) (ft / m)50.42 / 15.3750.42 / 15.3746.42 / 14.1549.42 / 15.06
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)73,000 / 33,11275,600 / 34,29268,000 / 30,84466,000 / 29,937
Engine Weight (lbs / kg)104,000 / 47,174110,150 / 49,96396,000 / 43,54596,000 / 43,545
Tender Loaded Weight (lbs / kg)69,000 / 31,29869,000 / 31,29860,000 / 27,21660,000 / 27,216
Total Engine and Tender Weight (lbs / kg)173,000 / 78,472179,150 / 81,261156,000 / 70,761156,000 / 70,761
Tender Water Capacity (gals / ML)3000 / 11.363000 / 11.363000 / 11.363000 / 11.36
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)6 / 66 / 6
Minimum weight of rail (calculated) (lb/yd / kg/m)41 / 20.5042 / 2138 / 1937 / 18.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)46 / 116846 / 116846 / 116846 / 1168
Boiler Pressure (psi / kPa)180 / 1240180 / 1240180 / 1240180 / 1240
High Pressure Cylinders (dia x stroke) (in / mm)16" x 22" / 406x55914" x 20" / 356x50815" x 22" / 381x55915" x 22" / 381x559
Low Pressure Cylinders (dia x stroke) (in / mm)14.25" x 20" / 362x508 (1)
Tractive Effort (lbs / kg)18,733 / 8497.1619,792 / 8977.5116,464 / 7467.9516,464 / 7467.95
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.90 3.82 4.13 4.01
Heating Ability
Tubes (number - dia) (in / mm)110 - 2" / 51110 - 2" / 51122 - 2" / 5198 - 2" / 51
Flues (number - dia) (in / mm)18 - 5.375" / 13718 - 5.375" / 13712 - 5.5" / 14018 - 5.375" / 137
Flue/Tube length (ft / m)15 / 4.5715 / 4.5715.50 / 4.7215.50 / 4.72
Firebox Area (sq ft / m2)122 / 11.33122 / 11.3396 / 8.9296 / 8.92
Grate Area (sq ft / m2)33.40 / 3.1033.40 / 3.1026 / 2.4226 / 2.42
Evaporative Heating Surface (sq ft / m2)1359 / 126.251359 / 126.251346 / 125.051277 / 118.64
Superheating Surface (sq ft / m2)282 / 26.20282 / 26.20238 / 22.11334 / 31.03
Combined Heating Surface (sq ft / m2)1641 / 152.451641 / 152.451584 / 147.161611 / 149.67
Evaporative Heating Surface/Cylinder Volume265.45381.38299.13283.80
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation6012601246804680
Same as above plus superheater percentage7034703453825663
Same as above but substitute firebox area for grate area25,69325,69319,87220,909
Power L112,14911,49812,16914,608
Power MT1100.711005.901183.591463.87

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