Data from "New Locomotives on the San [sic] Paulo Ry.", Locomotive Magazine, Volume 37 (14 February 1931), p. 41. (Thanks to Ivo Rutishauser for his 28 February 2026 email correcting the works number range.) Works numbers were 23946-23951 in 1930.
Although relatively small for a standard-gauge 2-8-4, this sextet's small drivers, long side tanks, and full cab combined with a Belpaire firebox to imply considerable heft to the passerby. They were described in LM as intended for "moderate-speed heavy freight service", but the relatively small fuel and water capacities suggest banking or transfer freight duties.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | 84 |
| Locobase ID | 20947 |
| Railroad | Sao Paulo |
| Country | Brazil |
| Whyte | 2-8-4T |
| Number in Class | 6 |
| Road Numbers | 84-89 |
| Gauge | Std |
| Number Built | 6 |
| Builder | North British |
| Year | 1931 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 15.50 / 4.72 |
| Engine Wheelbase (ft / m) | 35 / 10.67 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.44 |
| Overall Wheelbase (engine & tender) (ft / m) | 71.10 / 21.67 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | 156,464 / 70,971 |
| Engine Weight (lbs / kg) | 228,480 / 103,637 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | 1800 / 6.82 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 3.30 / 3 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 65 / 32.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 51 / 1295 |
| Boiler Pressure (psi / kPa) | 200 / 1380 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 21.5" x 26" / 546x660 |
| Tractive Effort (lbs / kg) | 40,062 / 18171.84 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.91 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | |
| Firebox Area (sq ft / m2) | 164 / 15.24 |
| Grate Area (sq ft / m2) | 28.50 / 2.65 |
| Evaporative Heating Surface (sq ft / m2) | 1599 / 148.55 |
| Superheating Surface (sq ft / m2) | 430 / 39.95 |
| Combined Heating Surface (sq ft / m2) | 2029 / 188.50 |
| Evaporative Heating Surface/Cylinder Volume | 146.36 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 5700 |
| Same as above plus superheater percentage | 6897 |
| Same as above but substitute firebox area for grate area | 39,688 |
| Power L1 | 9786 |
| Power MT | 551.55 |