Nord 6-2-0 Locomotives in France

Class Details by Steve Llanso of Sweat House Media

Class Alma (Locobase 11313)

Data from August Perdonnet et Camille Polonceau, Nouveau Portefeuille de L'Ingenieur des Chemins de Fer, Tome Second (Paris: Librairie Scientifique, Industrielle et Agricole, 1866), pp. 530-531. See also "Notes on Old Locomotives: Northern Railway of France", Locomotive Magazine, Volume XXVII [27] (15 December 1921), pp. 327-330.

This express design took the Crampton concept of a single set of high drivers behind the coke-burning firebox to an unwieldy extent. Putting three supporting axles under the boiler allowed a longer, heavier vessel, but exacerbated the low proportion of engine weight actually borne by the adhesion axle. The front two axles were equalized by an over-mounted spring; the third supporting axle was independent.

NB: When measured from the fire side (46 mm), tube heating surface area measured 91.42 sq m (984 sq ft); adding in the firebox area yielded 99.4 sq (1,070 sq ft) in evaporative heating surface area. Locobase uses the water side area in the specs.

LM reported in 1921 that the Alma and Inkerman were rated to haul 97 tons of trailing load in ordinary service and burning 8.5 kb (18 3/4 lb) per mile, 130 tons at a maximum at speeds up to 60 kph (37.3 mph) with a commensurate consumption increase to 11.5 kph (21 1/2 lb).

Jules Petiet later mounted his steam dryer on the 162's boiler; the modification added 1,000 kg (2,205 lb) to the engine's weight. (LM shows the large housing on top of the boiler on page 328.) This was a second, smaller cylinder containing 16.9 sq m (181.9 sq ft) fo tubes that (somewhat) removed the remaining water in the saturated steam created in the relatively low-pressure boilers of the day.

The steam dryer can't be counted a big success nor did the ultra-Crampton layout win many adherents. The 162 was scrapped in 1873.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID11313
Number in Class2
Road Numbers162-163
Number Built2
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)
Engine Wheelbase (ft / m)16.73 / 5.10
Ratio of driving wheelbase to overall engine wheelbase
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)27,778 / 12,600
Weight on Drivers (lbs / kg)27,778 / 12,600
Engine Weight (lbs / kg)70,989 / 32,200
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)1531 / 5.80
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)46 / 23
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)82.70 / 2100
Boiler Pressure (psi / kPa)113.10 / 7.80
High Pressure Cylinders (dia x stroke) (in / mm)16.54" x 21.65" / 420x550
Tractive Effort (lbs / kg)6885 / 3122.99
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.03
Heating Ability
Tubes (number - dia) (in / mm)173 - 1.969" / 50
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)12.01 / 3.66
Firebox Area (sq ft / m2)86.11 / 8
Grate Area (sq ft / m2)15.18 / 1.41
Evaporative Heating Surface (sq ft / m2)1157 / 107.50
Superheating Surface (sq ft / m2)182 / 16.90
Combined Heating Surface (sq ft / m2)1339 / 124.40
Evaporative Heating Surface/Cylinder Volume214.90
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1717
Same as above plus superheater percentage1957
Same as above but substitute firebox area for grate area11,103
Power L19339
Power MT741.20

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