Rhaetian Railway G 2/2+2/3
Under the designation G 2/2+2/3, the Rhaetian Railway operated two Mallets delivered by the SLM in 1896 for 65,500 Swiss Francs each. The G in the designation stood for a narrow gauge locomotive, while 2/2+2/3 stood for a leading bogie with two driving axles and a second group in the main frame that had also two driving axles and an additional trailing axle. All axles were mounted in outside frames. These locomotives can be seen as the follower of the two G 2x2/2 of the preceding Landquart-Davos Railway.
The requirements were that they could haul 70 tonnes on a 4.5 percent incline with 15 km/h. While the trailing axle was not present on the predecessors, it was added here to increase the supplies. In service it was found out that the trailing axle led to increased wear on both the tracks and wheel flanges. This is why the following G 2/3+2/2 had the carrying axle at the front. The two G 2/2+2/3, named “Maloja” and “Chiavenna”, were used by the RhB until 1926. Then they were sold to Oberhasli Power Plants company, who scrapped them in 1940.
Technical data
General
- Built
- 1896
- Manufacturers
- SLM
- Wheel arrangement
- 0-4-4-2T
- Gauge
- 1,000 mm (Meter gauge)
Dimensions and weights
- Length
- 10.34 m
- Wheelbase
- 6.60 m
- Empty mass
- 36.5 t
- Service mass
- 44.5 t
- Adhesion mass
- 40.2 t
- Rigid wheelbase
- 1.60 m
- Axle load
- 10.1 t
- Water capacity
- 3,400 l
- Fuel capacity
- 1.2 t (coal)
Boiler
- Grate area
- 1.3 m²
- Firebox surface
- 7 m²
- Tube heating surface
- 79 m²
- Evaporative heating surface
- 86 m²
- Total heating surface
- 86.0 m²
Power plant
- Driver diameter
- 1,050 mm
- Boiler pressure
- 14 bar
- Expansion type
- compound
- Cylinders
- four, HP: 330 x 550 mm and LP: 490 x 550 mm
Power
- Power source
- steam
- Estimated power
- 310 kW (421 PS)
- Starting effort
- 93.4 kN
- Starting effort simple
- 112.1 kN
Calculated values
- Factor of adhesion
- 1 : 4.22
- Optimal speed
- 21 km/h
- Power-to-weight ratio
- 7.0 kW/t
- Heating Surface Equivalent
- 121.0 m²
- Cylinder volume/HSE
- 1 : 1,634.70
- Adhesive weight/Total
- 1 : 1.11
- Tractive force/Heating surface
- 1 : 22.68
- Grate area/Heating surface
- 1 : 66.15
- Firebox/Tube surface
- 1 : 11.29