231 B Ouest

Infobox Locomotive
name=231 B
powertype=Steam
gauge=RailGauge|sg


caption=
builder=
builddate=1910
whytetype=4-6-2
railroadclass=231 B
numinclass=50
roadnumber=231-011 to 231-060
cylindercount=4
cylindersize=
driversize=
boilerpressure=
totalsurface=
superheaterarea=
gratearea=
fueltype=coal
tenderc

locotenderweight=
weightondrivers=
length=
railroad=Chemin de Fer de l'État
officialname=

The 231 B was a small class of 4-6-2 steam locomotive of the Chemin de Fer de l'État.

The series of 50 engines was built 1910. After some difficult early days, the engines became part of the SNCF's 231 class. The class was numbered 231-011 to 231-060 by the Chemin de Fer de l'État and 231 B 1 to 231 B 60 by the SNCF.The 231s was inspired by two engines; the firebox was the one of the Pacific 2900 and the wheels of the 230 J. They were coupled to 22 m³ and were very sober in appearance.

These engines had a tendency to derail, and forced the Chemin de Fer de l'État to change the leading bogies. Two of these accidents happened at Perray and the other at Bernay on 10 September 1910

After a temporary use solely on goods trains and at 60 km/h, the engines had their leading bogie modified and was reallocated to passenger service in 1912.

From 1912, the 231 Bs were allocated to the Bâtignoles and Vaugirard and mainly pulled express trains to Le Havre, Cherbourg, Le Mans, Thouars and on the Deauville Express.

Around 1922, half the class was moved to Dieppe which gave the class the nickname of "Dieppoises". Many did pull the express from Gare Saint-Lazare to Dieppe via Pontoise. From 1929, the class was responsible for the expresses between Dieppe and Le Mans and the Manche-Océan, between Dieppe and Bordeaux.

Several engines received smoke deflectors in 1931 as well ACFI feedwater heaters. The class was renumbered 231 B 1 to 231 B 60 in 1938.

Around 1945, a project including the increase of power to convert|1700|hp|abbr=on to create a class of 231 L engines failed and the engines ran until 1956.