2-6-2 Steam Locomotives in Argentina

Class Clase 8A (Locobase 3733)

Data provided by Carlos Alberto Fernandez Priotti in Bryan Attewell ([] Steam Locomotive simulator program (April 2000); and FC General Roca 6-1957 diagram book supplied in August 2021 by Allen Stanley from his extensive Rail Data Exchange collection. See also D[ouglas] S[tuart] Purdom, British Steam on the Pampas (London and New York: Mechanical Engineering Publications, Ltd:, 1977), pp. 42-43. Works numbers were 17124-17145, 17285-17296 in 1906.

Douglas Purdom stated that this relatively large tank engine order may been originally intended for India, but was diverted to Argentina, "but it has been impossible to trace any official record of this." Many years later, Locobase was able to combine an NBLC catalogue entry with a production list to determine some of the works numbers.

The engines presented a very British sight with cylinders outside and below the running board, inside valves, black smokebox and short stack, Belpaire firebox and roofed cab with large, windowless openings. The rear two axles of the coupled trio flanked the grate front and rear and leading and trailing trucks balanced the profile.

He contended that the class was "a remarkably good investment for the railway, being real maids of all work and able to perform efficiently every possible job within their rather limited fuel and water capacity."

They even proved able to take up the slack in the "intense" Buenos Aires suburban-service motive power shortage for several years from 1924.

Class Clase 8A-superheated (Locobase 21231)

Data from FC General Roca 6-1957 diagram book supplied in August 2021 by Allen Stanley from his extensive Rail Data Exchange collection. See also D[ouglas] S[tuart] Purdom, British Team on the Pampas (London and New York: Mechanical Engineering Publications, Ltd:, 1977), pp. 42-43. Works numbers were 17124-17145, 17285-17296 in 1906.

Locobase 3733 describes the 8A class as it originally came from North British Locomotive Company in 1906-1907. At the time, few if any British-built locomotives had superheaters. Over the years, the shops retrofitted all but eight with the improvement.

As noted in Locobase 3733, Douglas Purdom contended that the class was "a remarkably good investment for the railway, being real maids of all work and able to perform efficiently every possible job within their rather limited fuel and water capacity." It's likely that superheated 8As only enhanced their value.

Class Clase 8B (Locobase 4298)

Data from Carlos Alberto Fernandez Priotti in Bryan Attewell ([] Steam Locomotive simulator program (December 2000) and from "James Nasmyth's Centenary," The Locomotive Magazine, Volume XIV [14] (15 December 1908), p. 209-211. See also D[ouglas] S[tuart] Purdom, British Team on the Pampas (London and New York: Mechanical Engineering Publications, Ltd:, 1977), pp. 43-44.

As very little of the land around Buenos Aires yielded useful rock for ballast or for other building purposes, Purdom wrote, exploiting those quarries that could be opened in the Sierra Bayas hills required a particular Prairie tank design. The class proved "eminently successful", he contended, in the role for which they were "ordered specifically". Small drivers supplied by boilers pressed to a relatively high degree, and the 2-6-2's flexibility and weight distribution. Over the next six decades, Class 8Bs served the quarries little changed, although three ultimately burned oil.

Class Clase 8C (Locobase 4299)

Data from Carlos Alberto Fernandez Priotti in Bryan Attewell ([] Steam Locomotive simulator program (December 2000); "Superheater Tank Locomotive, Buenos Ayres Great Southern Ry", Locomotive Magazine, Volume XXV [25] (14 June 1919), p. 86; and FC General Roca 6-1957 diagram book supplied in August 2021 by Allen Stanley from his extensive Rail Data Exchange collection. See also D[ouglas] S[tuart] Purdom, British Team on the Pampas (London and New York: Mechanical Engineering Publications, Ltd:, 1977), pp. 44-45. Robert Stephenson & Company produced the first ten in 1913 (works numbers were 3471-3480). North British Locomotive followed with 31 more (works numbers 20186-20216 in 1913-1914).

Oil-burning suburban passenger tanks. They had inside admission piston valves and the tallest drivers of any Class 8 Prairie tanks. Purdom noted their descent from the Class 7D Moguls shown in Locobase . They were superheated when delivered, rolling on the same-size drivers, and bearing boilers pressed to a relatively high degree.

LM's report noted the virtues of the 2-6-2 arrangement as applied to tank engines. Setting three driven axles between a swivelling truck at each end "gives at once ample adhesion weight and full flexibility" while being "decidedly cheaper in first cost" than a 4-6-2 or a 4-6-4 locomotive as well as being "economical of weight that is useless for adhesion."

Purdom wrote that these were the tank version of the class 7D 2-6-0 tender engines. On their arrival, he continued, "They at once took over the bulk of the Buenos Aires suburban services including the longer runs unsuitable for the class 8A due to the restricted fuel capacity of the latter."

Most operated in the Buenos Aires suburbs, but a few were delivered to Bahia Blanca and the city of Tandil.

Class Clase 8DN (Locobase 4301)

Data from Carlos Alberto Fernandez Priotti in Bryan Attewell ([] Steam Locomotive simulator program (December 2000); and FC General Roca 6-1957 diagram book supplied in August 2021 by Allen Stanley from his extensive Rail Data Exchange collection . Beyer, Peacock works numbers 6246-6260 in 1925 and North British Locomotive Company works numbers werer 23156-23170 in 1925.

-Superheated repeats of the 8DVs a dozen years later. Also used for switching (shunting) duties.

Class Clase 8DV (Locobase 4300)

Data from Carlos Alberto Fernandez Priotti in Bryan Attewell ([] Steam Locomotive simulator program (December 2000). See also D[ouglas] S[tuart] Purdom, British Steam on the Pampas (London: Mechanical Engineering Publications, Ltd, 1977), pp. 46-47

Essentially the same as the 8C suburban passenger tanks supplied by Stephenson in the same period, but used for switching and consequently having no superheater, smaller drivers, and less water and fuel.

The Spanish-language website members.es.tripod.de/rielsud/locoayer.html (Dec 2001| quotes the last Chief Mechanical Engineeer of the Sud, Douglas Purdom, as noting that throughout their working lives, these engines would leave their home shed on Sunday for Kilo 5 -- their main working area -- and not return until the following Saturday. During that week they'd be in steam continuously and pause only to have water and oil refilled.