French State Railway 141 R
Since there was a major shortage of locomotives after the liberation of France in World War II and the North American manufacturers still had capacities, SNCF ordered a total of 1,340 Mikados for freight and passenger service. The actual design came from Baldwin and was based on the USRA Light Mikado, which was made a little lighter and adapted to the French loading gauge. The locomotives were easier to maintain than the French ones, being built after American principles, and quickly spread across the country. The coal-fired locomotives were almost exclusively used in front of freight trains and the oil-fired ones could also often be found in front of passenger trains. They remained in service until 1974, when all steam operations in France ceased.
Technical data
General
| Property | coal | oil |
|---|---|---|
| Built | 1945-1947 | |
| Manufacturers | Baldwin, ALCO, Lima, Montreal Locomotive Works, Canadian Locomotive Co. | |
| Wheel arrangement | 2-8-2 (Mikado) | |
| Gauge | 1,435 mm (Standard gauge) | |
Dimensions and weights
| Property | coal | oil |
|---|---|---|
| Length | 24.13 m | |
| Length loco | 14.64 m | |
| Wheelbase | 10.72 m | |
| Total wheelbase | 20.32 m | |
| Service mass | 116 t | |
| Adhesion mass | 80 t | |
| Total mass | 191 t | |
| Rigid wheelbase | 5.02 m | |
| Axle load | 20 t | |
| Water capacity | 30,000 l | |
| Fuel capacity | 11.5 t (coal) | 9,500 l (oil) |
Boiler
| Property | coal | oil |
|---|---|---|
| Grate area | 5.16 m² | |
| Firebox surface | 27.31 m² | |
| Tube heating surface | 223.53 m² | |
| Evaporative heating surface | 250.84 m² | |
| Superheater surface | 65.4 m² | |
| Total heating surface | 316.2 m² | |
Power plant
| Property | coal | oil |
|---|---|---|
| Driver diameter | 1,651 mm | |
| Boiler pressure | 15.5 bar | |
| Expansion type | simple expansion | |
| Cylinders | two, 597 x 711 mm | |
Power
| Property | coal | oil |
|---|---|---|
| Power source | steam | |
| Indicated power | 2,150 kW (2,923 PS) | |
| Top speed | 100 km/h | |
| Starting effort | 202.2 kN | |
Calculated values
| Property | coal | oil |
|---|---|---|
| Factor of adhesion | 1 : 3.88 | |
| Optimal speed | 64 km/h | |
| Power-to-weight ratio | 18.5 kW/t | |
| Heating Surface Equivalent | 518.2 m² | |
| Cylinder volume/HSE | 1 : 768.16 | |
| Adhesive weight/Total | 1 : 1.45 | |
| Tractive force/Heating surface | 1 : 13.36 | |
| Grate area/Heating surface | 1 : 61.29 | |
| Firebox/Tube surface | 1 : 8.18 | |
| Total/Superheater | 1 : 3.84 | |
