several Articulated Locomotives in France

Class Details by Steve Llanso of Sweat House Media

Class L'Avenir (Locobase 3596)

The "future" is what this locomotive represented to Jean Jacques Meyer, who had it built to showcase his 4-cylinder layout of two engine sets arranged face to face under a single boiler. The front set pivoted around a fixed point, the rear one followed curved guides. The design also featured one of the first uses of the Heusinger-Walschaerts radial valve gear that would come to dominate valve gear designs for the next century.

Demonstrations on various railroads in Switzerland (Jura Industrial, and Swiss Central) and Belgium (Grand Central) failed to impress and the locomotive wound up on the Charentes Railroad (SW France) where it was scrapped in 1886.

Reder (1974), Wiener (1930) and theTitre Rapports du jury mixte internationale publies sous la dir. de S.A.I le Prince Napoleon, presidente de la commission Imperial (Paris, Impremerie Imperiale, 1856) Collation [4]-LXXVI-1574-p. -[2]; Cote CNAM 8th Xae 53 - Mots mateiere Exposition internationale (1885; Paris); Industrie - 19e siecle; Produits industriels - 19e siecle, p. 233, hosted on, accessed 1 September 2005.

Principal Dimensions by Steve Llanso of Middle Run Media

Locobase ID3596
Number in Class1
Road Numbers
Number Built1
Valve GearHeusinger-Wals
Locomotive Length and Weight
Driver Wheelbase (ft / m) 9.52 / 2.90
Engine Wheelbase (ft / m)28.90 / 8.81
Ratio of driving wheelbase to overall engine wheelbase 0.33
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)111,353 / 50,509
Engine Weight (lbs / kg)111,353 / 50,509
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)111,353 / 50,509
Tender Water Capacity (gals / ML)
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)51.20 / 1300
Boiler Pressure (psi / kPa)145 / 10
High Pressure Cylinders (dia x stroke) (in / mm)13.38" x 21.62" / 340x549 (4)
Tractive Effort (lbs / kg)18,634 / 8452.25
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.98
Heating Ability
Tubes (number - dia) (in / mm)
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)
Firebox Area (sq ft / m2)
Grate Area (sq ft / m2)18.07 / 1.68
Evaporative Heating Surface (sq ft / m2)1642 / 152.60
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1642 / 152.60
Evaporative Heating Surface/Cylinder Volume233.35
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2620
Same as above plus superheater percentage2620
Same as above but substitute firebox area for grate area
Power L1
Power MT

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