Paulista 4-8-2 Locomotives in Brazil


Class Details by Steve Llanso of Sweat House Media

Class 102 (Locobase 15271)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Vol 72, pp. 139+. Works numbers were 57665-57666 in March 1924.

When the Paulista chose to adopt the Mountain wheel arrangement for its freight engines, they adopted a small boiler and cylinder volume compared to the other sub-standard-gauge Mountains that would go into service. 10" (254 mm) piston valves supplied the cylinders with superheated steam.

Even though they were small, they were a big engine for the railway and the management clearly saw them as headliners: "The finish of the locomotives," said the specification,"should be absolutely everything that the BLW can do. Be especially careful of painting and polishing, and that all lines suchas the edges of all motion work, rods, running boards and all other lines that are noticeable on the locos, have clean straight edges. Locos must be of strikingly handsome finish and appearance."


Class 104 (Locobase 15270)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Vol 72, pp. 128+ and Vol 78, pp. 241+. Works numbers were 58060-58063 in November 1924, 58859-58864 in December 1925, 58916-58921 in January 1926.

Among the several dozen sub-standard gauge Mountain entries available in Locobase, this is only one of two describing a three-cylinder design. (The other is the Brooks order for the Manila Railways Cape gauge delivered in 1921; see Locobase 9693.) The three small cylinders contained only 8% more cylinder volume than did the two cylinders used in the Paulista's earlier Baldwin Mountains (Locobase 15271), but the boiler was substantially larger, the grate slightly larger. The firebox grew in proportion to the rest of the boiler. Boiler pressure increased moderately.

All three had 8" (203 mm) piston valves for their cylinders with the central cylinder's valve operated from the left outside gear. A note in the specs for the 1925-1926 engines addressed an earlier problem: "Particular attention is requested in lining up valve motion to see that all parts move freely in order to avoid hard handling of reverse lever. (Previous engines [i.e. 104-107] were faulty in this respect.)"

The class operated in mixed-train service, where, like their two-cylinder predecessors, they were expected to glisten in their final lineaments. The specs offered an abbreviated reminder as to the final appearance of the locomotives: "Special care to be taken in paintng and polishing the locomotives and all lines such as edges of all motion work, running boards, etc., to have clean straight edges."

Principal Dimensions by Steve Llanso of Sweat House Media

Class102104
Locobase ID15271 15270
RailroadPaulistaPaulista
CountryBrazilBrazil
Whyte4-8-24-8-2
Number in Class216
Road Numbers102-103104-119 / 680-695
GaugeMetreMetre
Number Built216
BuilderBaldwinBaldwin
Year19241924
Valve GearSouthernSouthern
Locomotive Length and Weight
Driver Wheelbase (ft / m)12.75 / 3.8912.75 / 3.89
Engine Wheelbase (ft / m)30.25 / 9.2230.25 / 9.22
Ratio of driving wheelbase to overall engine wheelbase 0.42 0.42
Overall Wheelbase (engine & tender) (ft / m)58.04 / 17.6957.54 / 17.54
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)104,000 / 47,174113,000 / 51,256
Engine Weight (lbs / kg)153,000 / 69,400173,000 / 78,472
Tender Loaded Weight (lbs / kg)94,500 / 42,86594,500 / 42,865
Total Engine and Tender Weight (lbs / kg)247,500 / 112,265267,500 / 121,337
Tender Water Capacity (gals / ML)4500 / 17.054500 / 17.05
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)8 / 78 / 7
Minimum weight of rail (calculated) (lb/yd / kg/m)43 / 21.5047 / 23.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)48 / 121948 / 1219
Boiler Pressure (psi / kPa)185 / 12.80202 / 13.90
High Pressure Cylinders (dia x stroke) (in / mm)20" x 22" / 508x55917" x 22" / 432x559 (3)
Tractive Effort (lbs / kg)28,829 / 13076.6334,115 / 15474.32
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.61 3.31
Heating Ability
Tubes (number - dia) (in / mm)129 - 2" / 51160 - 2" / 51
Flues (number - dia) (in / mm)22 - 5.375" / 13727 - 5.375" / 137
Flue/Tube length (ft / m)19.08 / 5.8218.75 / 5.71
Firebox Area (sq ft / m2)129 / 11.98156 / 14.49
Grate Area (sq ft / m2)40.20 / 3.7344.30 / 4.12
Evaporative Heating Surface (sq ft / m2)2000 / 185.802429 / 225.66
Superheating Surface (sq ft / m2)494 / 45.89584 / 54.25
Combined Heating Surface (sq ft / m2)2494 / 231.693013 / 279.91
Evaporative Heating Surface/Cylinder Volume250.02280.18
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation74378949
Same as above plus superheater percentage892410,649
Same as above but substitute firebox area for grate area28,63837,499
Power L113,11915,779
Power MT1112.401231.39

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