Nord 4-4-2 Locomotives in France

Class Details by Steve Llanso of Sweat House Media

Class Series 2641 (Locobase 3899)

Data from the table presented on pages 370, 372 of the Groupe VI. - GTnie civil. - Moyens de transport. DeuxiFme partie. Classes 32 (Tome I), part of the series of Rapports du Jury Internationale of the Exposition Unverselle Internationale de 1900 Paris Exposition, hosted on the website of Le Conservatoire numTrique des Arts & MTtiers ([], Accessed 21 August 2005).

These were the first of the de Glehn Atlantics, about which OS Nock (RWC III, pl 101) says "It would not be an exaggeration to say that these locomotives ... are one of the famous classes ever to run anywhere in the world."

According to Gustav Reder (1974), they extended the de Glehn-du Bousquet system of compounding to a design with a much larger grate in a characteristic Belpaire firebox and consequently greater heating capacity. Like the earlier Eight-wheelers, these two had the Serve ribbed firetubes as well. Their performance exceeded specifications. Required to scale the 1/2% grade between St Denis and k-post 27.5 at 100 km/h (62 1/2 mph) pulling a 200-ton train, the prototype reached 105 km/h (66 mph); 60 mph was attainable with a 285-ton train.

See Locobase 1490 for the series-production Nord Atlantics.

Class Series 2643 (Locobase 1490)

Data from Maurice Demoulin, Locomotive Actuelle ... (Paris: Librairie Polytechnique Ch.Beranger, 1906). See also Hollingsworth (1982).

This is the first series production of the famous de Glehn compounds (see Locobase 3899 for the two trial horses). De Glehn's sytems used a complicated setup of two throttles and two sets of reversing gear to admit steam to high- and low-pressure cylinders at appropriate moments. As a result, de Glehn compounds could be run in one of five modes. As a result, says Hollingsworth, "the move from running a simple engine to driving a compound could be likened to moving up from strumming (sic) a piano to conducting a whole orchestra!"

The de Glehn system also featured divided drive. The inside low-pressure cylinders had slide valves, were set well forward over the leading truck axle and drove the first axle. The HP cylinders were outside, were supplied through piston valves, and drove the second axle. Unlike Webb's 3-cylinder compounds, however, the two driving axles were coupled.

The bullet-shaped dome stood between the axles, ahead of the Belpaire firebox. Internally finned Serve tubes filled the boiler. The front bogie was heavily framed and the drivers were partially hidden behind a low running board and splashers.

Performance met expectations. Nord rated these trains as capable of pulling 270 tons up a 13-mile-long 0.5% grade (between St Denis and Survilliers) at an average speed in excess of 62 mph.

Edouard Sauvage (On the Question of Locomotives of Great Power (Subject V for Discussion at the Seventh Session of the Railway Congress)). reported in 1904 that the class had "...made it possible materially to increase the ordinary speed of the quick trains from Paris to Calais, to Lille, to Liege." And they could be run longer"...the fast trains are hauled over their whole journey by the same locomotive: thus from Paris to Lille [251 km], from Paris to Boulogne [254 km], from Paris to Calais [298 km], and even from Paris to Liege [370 km]."

When superheated, they could pull 350 tons and meet a 60-mph schedule between Paris and Aulnoye.

(Note: the data in the table is from Reder (1974). Hollingsworth gives the following data, which must be from a rebuild applied to only one engine: 1,485 sq ft evaporative surface, 420 sq ft of superheater. OS Nock (RWC V, pl 81) illustrates the 1935 rebuild, which featured installation of a Lemaitre multiple-blast-pipe front end. Tufnell (1986) gives the class size as 99, which is baffling unless he's referring the total number of 4-4-2s produced in France.)

Principal Dimensions by Steve Llanso of Sweat House Media

ClassSeries 2641Series 2643
Locobase ID3899 1490
Number in Class233
Road Numbers2641-26422643-2675
Number Built233
Valve GearWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m) 6.99 / 2.13 7.05 / 2.15
Engine Wheelbase (ft / m)27.89 / 8.5027.89 / 8.50
Ratio of driving wheelbase to overall engine wheelbase 0.25 0.25
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)36,156 / 16,400
Weight on Drivers (lbs / kg)71,617 / 32,48572,819 / 33,030
Engine Weight (lbs / kg)138,893 / 63,001146,607 / 66,500
Tender Loaded Weight (lbs / kg)100,310 / 45,500
Total Engine and Tender Weight (lbs / kg)239,203 / 108,501
Tender Water Capacity (gals / ML)5280 / 206080 / 23.03
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 5.50 / 5 7.50 / 7
Minimum weight of rail (calculated) (lb/yd / kg/m)60 / 3061 / 30.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)80.30 / 204080.30 / 2040
Boiler Pressure (psi / kPa)227.70 / 15.70227.70 / 15.70
High Pressure Cylinders (dia x stroke) (in / mm)13.39" x 25.2" / 340x64013.39" x 25.2" / 340x640
Low Pressure Cylinders (dia x stroke) (in / mm)22.05" x 25.2" / 560x64022.05" x 25.2" / 560x640
Tractive Effort (lbs / kg)15,912 / 7217.5715,912 / 7217.57
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.50 4.58
Heating Ability
Tubes (number - dia) (in / mm)126 - 2.756" / 70126 - 2.756" / 70
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)13.78 / 4.2014.11 / 4.30
Firebox Area (sq ft / m2)164.04 / 15.24166.84 / 15.50
Grate Area (sq ft / m2)29.49 / 2.7429.49 / 2.74
Evaporative Heating Surface (sq ft / m2)2244 / 208.462368 / 220.03
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)2244 / 208.462368 / 220.03
Evaporative Heating Surface/Cylinder Volume546.37576.56
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation67156715
Same as above plus superheater percentage67156715
Same as above but substitute firebox area for grate area37,35237,989
Power L183848762
Power MT516.18530.55

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