Brazil National Railways class 142N
Around 1950, André Chapelon developed two modern locomotive types with the 2-8-4 and 4-8-4 wheel arrangements for several Brazilian railway companies. While the machine shown here was designated 142N, the larger one was designated 242N. The 142N was developed for a maximum axle load of around ten tonnes and was designed to burn lignite or wood. It was used in mixed service.
Despite the meter gauge, the locomotives were all modern in design. In order to achieve enough power with the fuels used, they had a large firebox with thermic syphons. The superheater could reach temperatures of up to 380°C. Depending on the operator, different tenders were used, some of which had six axles.
The 66 locomotives were built by an export consortium called “GELSA”, which in this case involved Fives-Lille, Schneider-Creusot and Cail. In reality, it turned out that the curves with radii down to 50 meters were narrower than expected, for which the locomotives were not really suitable. That's why they were rather unpopular with the crews, who called them “too modern”. Instead, the old British locomotives were often preferred.
Technical data
General
- Built
- 1951-1952
- Manufacturers
- GELSA
- Wheel arrangement
- 2-8-4 (Berkshire)
- Gauge
- 1,000 mm (Meter gauge)
Dimensions and weights
- Length
- 21.68 m
- Wheelbase
- 9.18 m
- Total wheelbase
- 18.45 m
- Service mass
- 70 t
- Adhesion mass
- 40.4 t
- Total mass
- 142.8 t
- Rigid wheelbase
- 4.11 m
- Axle load
- 10.1 t
- Water capacity
- 17,800 l
- Fuel capacity
- 12 t (coal)
Boiler
- Grate area
- 4 m²
- Firebox surface
- 19.7 m²
- Tube heating surface
- 102.54 m²
- Evaporative heating surface
- 122.24 m²
- Superheater surface
- 45 m²
- Total heating surface
- 167.2 m²
Power plant
- Driver diameter
- 1,270 mm
- Boiler pressure
- 15 bar
- Expansion type
- simple expansion
- Cylinders
- two, 434 x 560 mm
Power
- Power source
- steam
- Indicated power
- 1,250 kW (1,700 PS)
- Top speed
- 60 km/h
- Starting effort
- 105.9 kN
Calculated values
- Factor of adhesion
- 1 : 3.74
- Optimal speed
- 72 km/h
- Power-to-weight ratio
- 17.9 kW/t
- Heating Surface Equivalent
- 310.7 m²
- Cylinder volume/HSE
- 1 : 533.20
- Adhesive weight/Total
- 1 : 1.73
- Tractive force/Heating surface
- 1 : 13.22
- Grate area/Heating surface
- 1 : 41.81
- Firebox/Tube surface
- 1 : 5.21
- Total/Superheater
- 1 : 2.72