2-4-2 Steam Locomotives in France

Class 101 (Locobase 7595)

Data from from Ernest Polonceau, "Locomotives of the Paris-Orleans Railway", Railway Engineer, Volume 11, No 10 (October 1890), pp. 253-254, 328-332; "121 n° 77 à 86 du PO", William Frank Pettigrew, A Manual of Locomotive Engineering (London: Charles Griffin & Co, 1899), p. 351 and Charles Rous-Marten, "Modern French Locomotive Practice" (Cassier's Magazine 1901-1902, pp 11).

Both Pettigrew and Rous-Marten single out this trio as characteristic of the express passenger engine of the 2-4-2 layout. It was a bit bigger than the other PO engines of this arrangement, but it had the Polonceau type firebox (having a crown sheet of flanged plates riveted together), a Ten-Brinck water arch, and the typical two-dome steam system.

Class 171 (Locobase 21219)

Data from "121 n° 171 à 264 du PO" on the WikiPO at [], last accessed 11 November 2024.

Locobase 618 describes this class of Forquenot [full name Victor Forquenot de la Fortelle] express locomotives as they originally entered service with only the leading truck. Fitted with a Ten Brinck water chamber over the grate to increase heating surface.

Although seen by foreign observers as not really suitable for express service, the class showed staying power. Ten years after their introduction, 171s underwent modifications to improve their riding qualities by adding a trailing truck under the firebox. A new boiler included a new, larger firebox and grate.

Two steam domes--one over the firebox the other just behind the stack--were connected by a slender pipe. Between the two domes, the pipe passed through an intermediate, flat-top dome that held sand for the leading driving set.

Class 265/121 A (Locobase 21218)

Data from Titre Exposition universelle internationale de 1878 a Paris. Rapports du jury internationale..Volume Groupe VI - Classe 64. Rapport sur le materiel des chemins de fer. p. 50 (cnum.cnam.fr/CGI/fpage.cgi?8XAE277-11.1/54/100/312/0/0 (accessed 1 September 2005). See also [], accessed 6 November 2006, which details the long history of this arrangement on the PO; and "121 n° 51 à 76 du PO" on the WikiPO website at [], last accessed 4 November 2024. (Thanks to Alexander Blessing for his 15 October 2024 email noting two different 2-4-2 classes and supplying data from WikiPO. Locobase took the opportunity to update the pre-existing records and add new entries liike this.)

Production history from WikiPO:

265 à 288 Société Alsacienne in 1876-1877,

289 à 308 Ateliers de la Compagnie in 1877-1878,

309 à 328 Société Alsacienne in 1878,

329 à 348 Sharp, Stewart et Cie in 1882,

349 à 360 Société Alsacienne in 1877,

361 à 380 Société Saint-Léonard in 1882-1884,

381 à 390 Carel frères in 1883-1884

This balanced wheel arrangement was especially popular in France where several railways adopted it. On the PO, Victor Forquenot's design responded to the demands of the line's profile which featured adverse grades of 1 to 1.6% and curve radii measuring 300-500 metres. In the face of a relatively tight alignment, says the jury report, the extreme wheelbase was reduced as much as possible. To counteract the instability such close-coupling might induce, the locomotive-tender coupling was tightened with springs. Trimming weight growth meant resorting to a steel firebox in place of the more usual copper.

In part because the French engineers tweaked the design to address shortcomings, some of these 2-4-2s ran on through World War Two.

Class 366 (Locobase 7942)

Data from [] . These relatively large tanks with exceptionally tall drivers for tank engines were derived from the 2-4-2s shown in Locobase 7941. The tank engines served secondary lines on the Paris-Orleans. The driver diameter is surprising because such locomotives typically ran in local service that required frequent starts and stops. Consequently, they would use smaller drivers to gain more power and reduce slipping.

Class 448/121 B (Locobase 7941)

Data from "XII Locomotives des Trains a Tres Grande Vitesse," Compte Rendu General, Congres Internationale de Chemins des Fer, Sixieme Session, Troisieme Volume (Brussels, Belgium P Weissenbruch, 1901), pp. XII-51 to XII- . See also [] and from Maurice Demoulin, Traite Pratique de la Machine Locomotive (Paris Libraire Polytechnique, Baudry et Cie, 1898), p.91; and "121 n° 448 à 575 du PO" on the WikiPO website at [], last accessed 7 November 2024. (Thanks to Alexander Blessing for his 15 October 2024 email noting two different 2-4-2 classes and supplying data from WikiPO. Locobase took the opportunity to update the pre-existing records and add new entries liike this.)

Production history from WikiPO:

448 Ateliers de la Compagnie, mise en service 1879,

449 à 466 Ateliers de la Compagnie, mise en service 1880-1881,

467 à 482 Ateliers de la Compagnie, mise en service 1882-1883,

483 à 492 Wiener Neustadt, mise en service 1882-1883,

493 à 502 Cockerill, mise ne service 1883-1884,

503 à 510 Ateliers de la Compagnie, mise en service 1884

511, 512 Ateliers de la Compagnie, mise en service 1885

513 à 524 Société des Batignolles, mise en service 1884

525 à 540 Société des Batignolles, mise en service 1885

541 à 550 Société des Anciens Etablissements Cail, mise en service 1885

551 à 575 Schneider et Cnie, mise en service 1886-1887

This locomotive appeared in large numbers as a tender engine. In essence, it repeated much of the earlier large 265 class described in Locobase 21218. It had a Ten-Brinck firebox that used a water chamber in place of the earlier engines' brick arch and a single dome placed even further to the rear than earlier Forquenot 2-4-2s. Its boiler pressure increased by almost 2 bar (29 psi). Tracking used a lead truck that enjoyed lateral play and was centered using inclined planes.

Production extended over a decade and amounted to several dozen. Seventeen others with much taller drivers went into service as tank engines; see Locobase 7942.

In 1899, Ernest Polonceau modified eight of these engines with two domes, one placed well forward on the boiler and the other over the firebox. He also used the Durant-Lencauchez steam distribution system to feed their cylinders. See his "Corliss Valve Gear for Locomotive Engines", Engineering (26 February 1897) , pp. 291-294. This system used four cylindrical Corliss valves in each cylinder, two for admission, one at each end, and two exhaust valves under the cylinders.

Polonceau cited the rapid opening of the valves, the lesser drop in temperature and pressure in the small valve volume, even the higher back pressure when reversing the motion.

Class 51/121 A (Locobase 6938)

Data from Titre Exposition universelle internationale de 1878 a Paris. Rapports du jury internationale..Volume Groupe VI - Classe 64. Rapport sur le materiel des chemins de fer. p. 50 (cnum.cnam.fr/CGI/fpage.cgi?8XAE277-11.1/54/100/312/0/0 (accessed 1 September 2005). See also [], accessed 6 November 2006, which details the long history of this arrangement on the PO; and "121 n° 51 à 76 du PO" on the WikiPO website at [], last accessed 4 November 2024. (Thanks to Alexander Blessing for his 15 October 2024 email noting two different 2-4-2 classes and leading Locobase to update this later series.)

Production history from WikiPO:

Société Alsacienne 51 à 60 en 1885,

Société des Batignolles 61 à 76 en 1885-1886

This balanced wheel arrangement was especially popular in France where several railways adopted it. Locobase 21218 describes designer Forquenot's goals in designing the original express passenger engine.

In part because the French engineers tweaked the design to address shortcomings, some of these 2-4-2s ran on through World War Two.

Class 77/Express (Locobase 7408)

Data from Titre Exposition universelle internationale de 1889 a Paris. Rapports du jury internationale. Auteur - Volume France. Ministere du Commerce, de l'industrie. Picard, Alfred, ed. Volume Groupe VI - -Outillage et precedes des industries mecaniques. Electricite (5e partie) Classes 60 a 63. Rapport sur le materiel des chemins de fer; tables beginning on p. 183 ([] (accessed 1 September 2005)).

Twelve years after displaying a 2-4-2 at the 1878 Exposition (Locobase 6938), the Orleans came back with a larger and more powerful version. Designed to pull 224 tons, the design boasted one of the largest fireboxes used in such service, but slightly smaller boiler than the earlier engine.. It was heavier than the 1873 design shown in the earlier expo, and sported a significantly higher boiler pressure. The result was a relatively powerful express engine with tall drivers.