4-6-0 Steam Locomotives in Brazil

Class 110 (Locobase 12223)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 20, p. 215. Works numbers were 15071-15072 in October 1896.

Class 124 (Locobase 20858)

Data from Lionel Wiener, Les chemins de fer du Bresil (Paris: H. Dunod et E Pinat, Editeurs, 1912), p. 131. (Thanks to Teemu Koivumaki whose 2023 email included a comprehensive spreadsheet of Brazilian steam locomotive builders, works numbers, and owners.) Locobase cannot identify any locomotives in Temmu's spreadsheet that match Wiener's description (see below).

Wiener, a long-term observer of Brazilian railroading, disagreed with Mogyana Shops' construction of some of their locomotives, including this quintet. It represented an "economic error" in that Brazil didn't produce its own coal. He argued that the railways shouldn't spend its resources on acquiring an indigenous locomotive industry. Mogyana's attempt, he argued, would always lead to dependence on government subsidies.

NB: Tube heating surface shown in Lionel Wiener's table resulted from calculations using tube inside diameters ("fire side"); it was given as 64.4 sq m (693 sq ft). the table shows the external diameter, from which both the tube and evaporative heating surfaces in Locobase are derived.

Class 176 (Locobase 13969)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 44, p. 105. Works numbers were 38680-38681 in November 1912.

Near-repeats of the 2 Ten-wheelers built for the Mogyana earlier in the year (Locobase 13779), this pair had narrower grates. The specs explain that the firebox slimmed down "in order to provide more clearance between the outside sheets of firebox and the tires of the rear driving wheels."

They also switched from the Emerson superheater to the Schmidt design, which had gained a strong following by that time and would dominate the superheater market from then on. The 176-177 put more weight on the rails, had more room and better ventilation in the cab, and trailed tenders that were shorter and higher to allow the engine-tender combination to fit easily on the 49 ft-diameter (14.9 metre) turntables.

Class 178 (Locobase 13967)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 44, p. 98. Works numbers were 38814 in December 1912, 39027-39030 in January 1913.

Although intended for the same gauge as the superheated Ten-wheelers shown in Locobase 13779, this quintet was part of a larger order of smaller locomotives. A relatively high boiler pressure gave the set outsized power to scale 3% grades and negotiate 100-metre (328-ft) uncompensated curves. The specs limited axle loading to 8 long tons and engine weight to 30 long tons. (Another detail concerned the wrist pins on the front and rear drivers. These took the thrust of the relevant side rod and translated it into rotary motion. They were to be identical, says the spec, so that a front driver could be interchanged with a rear one or vice versa.)

The 178s were soon followed by a larger group of superheated variants; see Locobase 13968.

Class 183 (Locobase 13968)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 44, p. 101. Works numbers were 40010-40015 in June 1913.

Given the opportunity to compare a saturated-boiler engine with its superheated twin, Locobase was surprised to find that the combined heating surface of the later was a bit larger. In most other cases where the modification to the locomotive was limited to the boiler, heating surface usually dropped because of the tradeoff between tubes and flues. Moreover, railroads often reduced the boiler pressure setting when the design was superheated.

The Mogyana did neither with this sextet (at least when they were delivered) and the result was a small, powerful freight hauler for the axle loading and gauge.

Class 193 (Locobase 13970)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 49, p. 167. Works numbers were 40676-40677 in September 1913.

Ten months after the revised Ten-wheeler design for Mogyana rolled off Baldwin's line (Locobase 13969), the railway ordered another pair with fewer small tubes and a few more flues to hold more superheater elements. Possibly this change occurred because the loss of superheater area that came with switching from an Emerson installation to the Schmidt resulted in lower-temperature steam in the cylinders than the change was supposed to yield.

Otherwise, the design repeated the dimensions and weights of the 176-177.

Class 220 (Locobase 4422)

Data from narrowmind.railfan.net. Works numbers were 67701-67702 in November 1928.

Little Ten-wheeler with high-pitched boiler, superheater, and Walschaert valve gear.

Class 34 (Locobase 13779)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 39, p. 249. Works numbers were 37501 in January 1912 and 37576 in March.

Like other Baldwins of the time, this pair was delivered with the Emerson superheater, which generated lower temperatures than the more widely used Schmidt type. Later locomotives of this class (Locobases 13969-13970) would use the Schmidt version.

Class unknown (Locobase 20852)

Data from Lionel Wiener, Les chemins de fer du Breñsil (Paris: H. Dunod et E Pinat, Editeurs, 1912), p. 115. Works numbers wer 4305-4308 in 1901.