Etat 4-6-2 Locomotives in France


Class Details by Steve Llanso of Sweat House Media

Class 231 G - 1936 rebuild (Locobase 5507)

One of the batches mentioned in Locobase 5324, these were the 30 that were fitted with the Dabeg oscillating cam poppet valves on all cylinders. Then reclassed as 231 DD (double Dabeg, i.e., on both HP and LP cylinders), they were redesignated 231 G when the SNCF was formed in 1937.

Daniel Broussard of Pacific Vapeur Club -- [link] (1 May 2003) -- notes that some of the small tubes were replaced by larger superheater flues. Some of the other goodies added at this time were a KylChap double exhaust, ACFI feedwater heater and pump, Armand water treatment (Sodium Carbonate, caustic soda, and tannin), Timken roller bearings in the lead bogie.

The Gs went into service on the boat trains, the Paris-Bordeaux run via Chartres, and ultimately the Nantes-Le Croisic. It was rated at 600 tonnes (13 coaches) at 120 km/h (74 1/2 mph) and 500 tonnes (11 coaches) and reaching 130 km/h (80.7 mph). Average water consumption was 2,600 to 3,900 US gal per 62 miles (100 km).

G 558 was restored in the 1980s during 8,000 hours of labor (4 full man-years) and is used for museum runs.


Class 231-501 (Locobase 5324)

Data from Edouard Sauvage, "Recent Development of Express Locomotives in France", Mechanical Engineer, (31 July 1914), pp. 95-98 and (7 August 1914), pp. 131-, with accompanying table. See also "British Built Locomotives for French State Railways", Locomotive Magazine, Volume XXII [22] (15 June 1916), pp. 109-110.

Although very similar to the last batch of de Glehn-Solacroup compound Pacifics for the PO, these engines, originally ordered by the Ouest, had round-top boilers instead of the PO engines' Belpaire firebox. After adoption as a standard Pacific design by the SNCF, all but 100 went to the Etat lines. The remainder stocked the Alsace-Lorraine Railway as the S14.

Chapelon-style rebuilds were extended to 269 of the Class 231s, resulting in the following sub-classes:

-- 134 231.D with Dabeg poppet valves fitted to the LP cylinders (see Locobase 2587) ;

-- 23 231.F using Willoteaux double piston valves on the LP side;

-- 30 231.G using oscillating cam poppet valves on all cylinders;

-- 85 231.H which had only adjustments to their existing valve gear setups.


Class 231.11 (Locobase 15170)

Data from "Etat 231-011 to 231-060", Wikipedia at [link], last accessed 4 May 2013. See also "Pacific Express Locomotives for the French State Railways (Western System)", Locomotive Magazine, Volume 18 (15 April 1912), p. 72. Fives-Lille produced 20 locomotives as did Schneider (Le Creusot) and SFCM delivered 10.

Introduced in 1910, these engines were based on the recent pair of Ouest Pacifics shown in Locobase 2754. The class quickly displayed some problems with the front bogie, which led to two derailments in short order. After the bogie was redesigned, a temporary 60 km/h (37 mph) speed limit was lifted and the class went into service. They had Belpaire fireboxes

According to Wikipedia, they were first based at Batignoles and Vaugirard and headed the Deauville Express as well as trains to Cherbourg, Le Havre, Le Mans, and Thouars.

Their later nickname of "Dieppoises" came from their 1922 reassignment to Dieppe, where they pulled expresses between Paris's Gare Saint-Lazare to Dieppe via Pontoise. In 1929 they hauled Dieppe-Le Mans expresses. Some were upgraded in the 1930s, but a major conversion that would have increased their rated horsepower to 1,700 (Class 230 L) envisaged in 1945 did not occur and the class operated essentially unmodified until their retirement in 1957.

Principal Dimensions by Steve Llanso of Middle Run Media
Class231 G - 1936 rebuild231-501231.11
Locobase ID5507 5324 15170
RailroadEtatEtatEtat
CountryFranceFranceFrance
Whyte4-6-24-6-24-6-2
Number in Class3140050
Road Numbers231-501 a 231-783231.11-231.60/231 B.1-50
GaugeStdStdStd
Number Built40050
Buildershopsseveralseveral
Year193619141910
Valve GearWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)13.78 / 4.2013.45 / 4.1012.96 / 3.95
Engine Wheelbase (ft / m)36.85 / 11.2335.76 / 10.9035.27 / 10.75
Ratio of driving wheelbase to overall engine wheelbase 0.37 0.38 0.37
Overall Wheelbase (engine & tender) (ft / m) / 19.5961.79 / 18.84
Axle Loading (Maximum Weight per Axle) (lbs / kg)39,242 / 17,800
Weight on Drivers (lbs / kg)118,944 / 55,700117,727 / 53,400
Engine Weight (lbs / kg)229,280 / 104,000209,664 / 96,500200,620 / 91,000
Tender Loaded Weight (lbs / kg)132,277 / 60,000115,522 / 52,400112,436 / 51,000
Total Engine and Tender Weight (lbs / kg)361,557 / 164,000325,186 / 148,900313,056 / 142,000
Tender Water Capacity (gals / ML)6077 / 23.025808 / 225808 / 22
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)13.20 / 12 6.60 / 6 6.60 / 6
Minimum weight of rail (calculated) (lb/yd / kg/m)66 / 3365 / 32.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)76.40 / 194177.20 / 196072.80 / 1850
Boiler Pressure (psi / kPa)232.10 / 1600232.10 / 1600227.70 / 1570
High Pressure Cylinders (dia x stroke) (in / mm)16.54" x 25.6" / 420x65016.54" x 25.59" / 420x65014.96" x 25.2" / 380x640
Low Pressure Cylinders (dia x stroke) (in / mm)25.2" x 25.6" / 640x65025.2" x 25.59" / 640x65023.62" x 25.2" / 600x640
Tractive Effort (lbs / kg)25,279 / 11466.3825,008 / 11343.4521,402 / 9707.80
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.76 5.50
Heating Ability
Tubes (number - dia) (in / mm)119 - 2.17" / 55151 - 2.165" / 55238 - 2.165" / 55
Flues (number - dia) (in / mm)30 - 5.24" / 13324 - 5.236" / 133
Flue/Tube length (ft / m)19.35 / 5.9019.36 / 5.9020.67 / 6.30
Firebox Area (sq ft / m2)176.53 / 16.37150.16 / 13.95
Grate Area (sq ft / m2)45.96 / 4.2745.96 / 4.2745.21 / 4.20
Evaporative Heating Surface (sq ft / m2)2128 / 197.772272 / 211.973190 / 296.38
Superheating Surface (sq ft / m2)824 / 76.58684 / 63.50
Combined Heating Surface (sq ft / m2)2952 / 274.352956 / 275.473190 / 296.38
Evaporative Heating Surface/Cylinder Volume334.26357.02622.23
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation10,66710,66710,294
Same as above plus superheater percentage13,65413,12110,294
Same as above but substitute firebox area for grate area50,39634,191
Power L118,8228519
Power MT1046.59478.59

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