Nord / SNCF 4-6-4 Locomotives in France


Class Details by Steve Llanso of Sweat House Media

Class 232R (Locobase 9979)

Data from "Portrait 232R-S," Rail Magazine [in French], No. 7, (November 1977), pp. 20-23. See also diagram UG Type 195, Societe Alsacienne de Construction Mecaniques from SACM locomotive book supplied by Dany Machi up at [] as

Diagrammes des machines SACM construites a GRAFENSTADEN (October 2007). Works numbers were 7756-7758 in 1940.

According to the RM author (whose name is not apparent in the article), this trio and the quartet of compounds shown in Locobase 9980 were products of a Nord decision to enlarge as many dimensions and areas in their current express designs under the watchphrase "robustesse engendre economie" (strength creates economy, or there is economy in strength).

The Nord's Chief of Locomotive Design, Marc de Caso, created a high-axle-load, high-pressure engine in a streamlined casing. The author implies that it was de Caso's experience with German engines that led him to test the three-cylinder simple layout shown in this entry against a four-cylinder compound arrangement much more typical of French practice.

A large boiler included a combustion chamber ahead of the Belpaire firebox. In the simple variant, all three cylinders lay in a line under the smokebox and drove the second coupled axle. Zara valves actuated by Dabeg rotary valves, ACFI (Compagnie des Auxiliaires des Chemins de Fer et de l'Industrie) water treatment system, Thermix ZCV injectors, and Lemaitre blast pipes were among the accoutrements. The fourth locomotive of the class was to test a turbine-drive system, but that locomotive was not completed.

The engines came into service just at the time of France's enforced armistice with Nazi Germany. Nevertheless, they did put up some stout performances - R2 pulled 676 tons up the 0.4% grade at Gannes, hitting 113.5 km/h / 70.4 mph as it did so and achieving an indicated horsepower rating of 2,616.


Class 232S (Locobase 9980)

Data from "Portrait 232R-S," Rail Magazine [in French], No. 7, (November 1977), pp. 20-23. See also

Data from diagram UG Type 196, Societe Alsacienne de Construction Mecaniques from SACM locomotive book supplied by Dany Machi up at [] as

Diagrammes des machines SACM construites a GRAFENSTADEN (October 2007). Works numbers were 7760-7763 in 1941.

As noted in Locobase 9979, the Nord chose to acquire two designs of streamlined express passenger engines in 1938 to test simple-expansion against compounding. The simple variant is shown in Locobase 9979. In this entry are the quartet of four-cylinder compounds.

As with the 232Rs, these 232S engines had Zara valves actuated by Dabeg rotary valves, ACFI water treatment system, Thermix ZCV injectors, and Lemaitre blast pipes. Again as noted in 9979, these engines could put up some hearty numbers. 232 S4 took a 585-ton train up a 0.5% grade at 112 km/h (70 mph) on 20 September 1945, indicating 3,400 hp.

Presumably the 232Rs had valve-gear problems - certainly the S variant did with its layout of 2 HP and 2 LP cylinders. As a result, the SNCF replaced the Dabegs in 1953-1954 with an oscillating cam system similar to what Chapelon had installed on his 231E locomotives.

Principal Dimensions by Steve Llanso of Sweat House Media

Class232R232S
Locobase ID9979 9980
RailroadNord / SNCFNord / SNCF
CountryFranceFrance
Whyte4-6-44-6-4
Number in Class34
Road Numbers232 R1 to 232 R3232 S1-232 S4
GaugeStdStd
Number Built34
BuilderSACMSACM
Year19401941
Valve GearDabegDabeg
Locomotive Length and Weight
Driver Wheelbase (ft / m)14.40 / 4.3914.40 / 4.39
Engine Wheelbase (ft / m)39.34 / 11.9939.34 / 11.99
Ratio of driving wheelbase to overall engine wheelbase 0.37 0.37
Overall Wheelbase (engine & tender) (ft / m)74.11 / 22.5974.11 / 22.59
Axle Loading (Maximum Weight per Axle) (lbs / kg)50,706 / 23,00050,706 / 23,000
Weight on Drivers (lbs / kg)138,891 / 63,000145,505 / 66,000
Engine Weight (lbs / kg)274,475 / 124,500278,884 / 126,500
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)10,000 / 37.8810,000 / 37.88
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 9.90 / 9 9.90 / 9
Minimum weight of rail (calculated) (lb/yd / kg/m)77 / 38.5081 / 40.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)78.70 / 200078.70 / 1999
Boiler Pressure (psi / kPa)285.70 / 19.70290.10 / 20
High Pressure Cylinders (dia x stroke) (in / mm)21.26" x 27.56" / 540x700 (3)17.91" x 27.56" / 455x700
Low Pressure Cylinders (dia x stroke) (in / mm)26.77" x 27.56" / 680x700
Tractive Effort (lbs / kg)57,657 / 26152.8138,269 / 17358.55
Factor of Adhesion (Weight on Drivers/Tractive Effort) 2.41 3.80
Heating Ability
Tubes (number - dia) (in / mm)137 - 2.126" / 54137 - 2.126" / 54
Flues (number - dia) (in / mm)33 - 5.63" / 14333 - 5.63" / 143
Flue/Tube length (ft / m)15.91 / 4.8515.91 / 4.85
Firebox Area (sq ft / m2)269.10 / 25269.10 / 25
Grate Area (sq ft / m2)55.76 / 5.1855.76 / 5.18
Evaporative Heating Surface (sq ft / m2)2099 / 1952099 / 195
Superheating Surface (sq ft / m2)742 / 68.96742 / 68.96
Combined Heating Surface (sq ft / m2)2841 / 263.962841 / 263.96
Evaporative Heating Surface/Cylinder Volume123.58261.20
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation15,93116,176
Same as above plus superheater percentage20,07320,382
Same as above but substitute firebox area for grate area96,87198,363
Power L122,33321,454
Power MT1063.48975.18

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