Midi 2-6-0 Locomotives in France

Class Details by Steve Llanso of Sweat House Media

Class 1801 / 130 B (Locobase 6792)

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).

The Jury report tells us that these four locomotives were rebuilt at Midi's Bordeaux shops from 0-6-0s originally supplied in time for the 1867 Exposition. Classic Bourbonnaises, they were relatively modestly powered with a boiler pressed to 8.5 atm (120 psi). The makeover entailed substantial revision and replacement. A completely new Belpaire firebox reformed the profile as did the Bissel leading truck. Serve finned boiler tubes occupied the barrel.

The smaller high-pressure cylinder was located outside of the right side of the boiler; the large low-pressure cylinder mirrored the HP location on the left side. The intermediate reservoir (chamber) took the HP cylinder's exhaust and reheated it before sending it to the LP cyilnder. Its tube had a diameter of 170 mm (6.7") and encompassed 272 litres (9.6 cu ft) as it curved inside the circumference of the smokebox. Its output valve would not open unless the pressure measured 5 kg/cm2 (4.9 bar or 71 psi) or less.

The revamped locomotives were rated as follows:

700 tons up a 0.5% grade at 25 km.h (15.5 mph)

260 tons up a 0.5% grade at 75 km/h (47 mph), and

130 tons on the level at 100 km/h (62 mph).

The Midi was pleased enough with the makeover to extend the program to 46 other engines. In 1938, when the SNCF was formed, all 50 were still in service and all 50 were taken into the nationalized system.

Principal Dimensions by Steve Llanso of Sweat House Media

Class1801 / 130 B
Locobase ID6792
Number in Class50
Road Numbers1801-1850/130 B 801 - 850
Number Built
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)13.12 / 4
Engine Wheelbase (ft / m)21.65 / 6.60
Ratio of driving wheelbase to overall engine wheelbase 0.61
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)91,492 / 41,500
Engine Weight (lbs / kg)117,286 / 53,200
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)51 / 25.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)63.40 / 1610
Boiler Pressure (psi / kPa)217.60 / 15
High Pressure Cylinders (dia x stroke) (in / mm)17.72" x 25.59" / 450x650 (1)
Low Pressure Cylinders (dia x stroke) (in / mm)26.77" x 25.59" / 680x650 (1)
Tractive Effort (lbs / kg)16,300 / 7393.56
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.61
Heating Ability
Tubes (number - dia) (in / mm)104 - 2.756" / 70
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)13.78 / 4.20
Firebox Area (sq ft / m2)130.30 / 12.11
Grate Area (sq ft / m2)23.13 / 2.15
Evaporative Heating Surface (sq ft / m2)1896 / 176.24
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1896 / 176.24
Evaporative Heating Surface/Cylinder Volume519.15
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation5033
Same as above plus superheater percentage5033
Same as above but substitute firebox area for grate area28,353
Power L17027
Power MT507.97

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