Ferrovie Nord Milano class 290
Although the FNM also operated an electrified suburban network around Milan, steam locomotives were needed for the more distant destinations. A tank locomotive was commissioned to speed up traffic, which should combine good acceleration with a maximum speed of 100 km/h. The order went to CEMSA, whose works in Saronno were located along the line of the FNM.
The four locomotives were apparently based on plans that came from Borsig. The 2-6-4T wheel arrangement was typical of modern passenger tank locomotives and combined good running characteristics with a large firebox and large supplies. The boiler delivered 1,060 hp permanently and 1,200 hp for short periods. The three cylinders, together with the 1,620 mm large driving wheels, ensured good acceleration.
The locomotives were used to run direct connections from Milan to Como, Varese, Laveno, Erba and Asso. For some other lines, the axle load of 16.5 tonnes was too high. After the main lines had been electrified, these locomotives could not be used on the secondary lines. So they were retired in 1952 and scrapped shortly thereafter.
Technical data
General
- Built
- 1931
- Manufacturers
- CEMSA
- Wheel arrangement
- 2-6-4T (Adriatic)
- Gauge
- 1,435 mm (Standard gauge)
Dimensions and weights
- Length
- 14.65 m
- Wheelbase
- 11.15 m
- Empty mass
- 77 t
- Service mass
- 96 t
- Adhesion mass
- 49.5 t
- Rigid wheelbase
- 3.90 m
- Axle load
- 16.5 t
- Water capacity
- 9,000 l
- Fuel capacity
- 2.5 t (coal)
Boiler
- Grate area
- 3.1 m²
- Evaporative heating surface
- 149 m²
- Superheater surface
- 52 m²
- Total heating surface
- 201.0 m²
Power plant
- Driver diameter
- 1,620 mm
- Boiler pressure
- 16 bar
- Expansion type
- simple expansion
- Cylinders
- three, 450 x 660 mm
Power
- Power source
- steam
- Indicated power
- 780 kW (1,061 PS)
- Top speed
- 100 km/h
- Starting effort
- 168.3 kN
Calculated values
- Factor of adhesion
- 1 : 2.89
- Optimal speed
- 29 km/h
- Power-to-weight ratio
- 8.1 kW/t
- Adhesive weight/Total
- 1 : 1.94
- Tractive force/Heating surface
- 1 : 17.49
- Grate area/Heating surface
- 1 : 64.84
- Total/Superheater
- 1 : 2.87