Ouest 2901 and 2902

Ouest 2901 and 2902
Ouest 2901
Type and origin Power type Steam Designer Robert Dubois, Maurice Demoulin Builder Ouest Workshops Sotteville-Quatre-Mares Build date 1908 Total produced 2
Specifications Configuration: ​  • Whyte 4-6-2  • UIC 2′C1′ n4v Gauge 1,435 mm (4 ft 8+1⁄2 in) Leading dia. 960 mm (3 ft 1.80 in) Driver dia. 2,080 mm (6 ft 9.89 in) Trailing dia. 1,370 mm (4 ft 5.94 in) Axle load 17.85 t (39,400 lb) Adhesive weight 53.55 t (118,100 lb) Loco weight 90.7 t (200,000 lb) Tender weight 57.8 t (127,400 lb) Total weight 148.5 t (327,400 lb) Tender type Bogie tender Fuel type Coal Fuel capacity 9 t (19,800 lb) Water cap. 24,000 L (5,300 imp gal; 6,300 US gal) Boiler pressure 16 kg/cm2 (1.57 MPa; 228 psi) Cylinders Four (Compound: 2 HP inside, 2 LP outside) High-pressure cylinder 400 mm × 640 mm (15.75 in × 25.20 in) Low-pressure cylinder 660 mm × 640 mm (25.98 in × 25.20 in)
Performance figures Tractive effort 103 kN (23,160 lbf)
Career Operators Ouest → État Numbers Ouest: 2901, 2903 → État: 6001, 6002 → État: 231-001, 231-002 Withdrawn 1928

Ouest 2901 and 2902 were two Pacific (4-6-2) type steam locomotive of the Chemins de fer de l'Ouest. They served in the west of France. The two prototypes were built in 1908 and were retired from service in 1928. They didn't lead directly to a series production but influenced the design of the État 231-011 to 231-060, the first Pacifics of the Chemins de fer de l'État.

Background

In anticipation of the increasing weight of trains, the Chemins de fer de l'Ouest decided in 1904 to develop a new type of locomotive for service on the Paris to Brest and Cherbourg lines, which featured gradients of 10 per mille that slowed down the trains. Under the leadership of Robert Dubois and Maurice Demoulin, engineers in the rolling stock and traction department, these locomotives were designed. Unfortunately, financial difficulties delayed the construction of the two prototypes until 1908.

Design

These non-superheated locomotives featured a four-cylinder compound engine with internal high-pressure cylinder and external low-pressure cylinder, both controlled by Walschaerts valve gears. The low and high-pressure cylinders had separate valve gears. Initially, both valve gears were located outside, despite the high-pressure cylinders being inside. Due to operational issues, the valve gear for the high-pressure cylinders was redesigned and relocated inside.

According to the De Glehn concept, the high-pressure cylinders operated on the first driver and the low-pressure cylinders operated on the second driver. The boiler was equipped with a Belpaire firebox. The leading bogie had internal side members and had a lateral displacement of ± 50 mm (1.97 in), while the Bissel truck had a lateral displacement of ± 70 mm (2.76 in). The blastpipe was of the type used by the Chemins de fer du Nord witch included an adjustable cone.

The locomotives made a strong impression due to their considerable height, featuring a running board completely clear of the wheels. The boiler was unusually long, with a tube length of 6 m (19.69 ft) and a long smokebox which also housed the steam exchange ducts between the groups of cylinders. However, the design of the locomotives was criticized for having a narrow cab, a design constraint imposed by the restrictive gauge of the Chemins de fer de l'Ouest.

Career

Upon leaving the company's manufacturing workshop in Sotteville-Quatre-Mares, the 2901 was presented during in August 1908 for one month alongside the historic 2-2-2 locomotive No. 33 "St. Pierre", built in 1844 for the Compagnie du chemin de fer de Paris à Rouen, at the Gare Saint-Lazare in Paris. Afterwards, it was assigned to the Batignolles, where valve gear problems emerged from the very beginning of the tests. Necessary adjustments were delayed due to the takeover of the Chemins de fer de l'Ouest by the Chemins de fer de l'État. When time was finally available, additional boiler issues surfaced mainly caused by the very long smoke box.

Tests on the Paris–Le Havre railway and on the Paris to Cherbourg line followed, during which rescue locomotive were frequently needed due to valve gear issues. The locomotives were transferred to the Paris-Vaugirard depot and included in the rotation of the 4-6-0 locomotives of the Ouest 2700 series providing fast express services to Brittany as best they could.

However, the Chemins de fer de l'État could not wait longer for reliabel express train locomotives. They built new Pacific locomotives using the Bissel truck and the boiler from the prototypes, but with longer tubes and a shorter smoke box. The engine was taken from the État 3800 series 4-6-0 locomotives. These new Pacifics were the État 231-011 to 231-060, later known as SNCF 3-231 B 11 to 60.

The État re-registered the locomotives as 6001 and 6002 and transferred them to the Chartres depot. In 1909, they were renumbered to 231.001 and 231.002. By 1910, the new Pacific locomotives displaced the two prototype from the fast express train services to slower trains and even freight train services. Despite not being designed for such services, they towed coal trains to the old Paris-Champ-de-Mars station.

Ultimately, the locomotives were retired in 1928 after a relatively short service period. However, the boiler of one of the prototypes continued to serve as stationary steam generator in the Sotteville workshops.