Cape Government Railways class 4 4-4-2
South African class 04 4-4-2
Almost identical to the Japanese Atlantics with the JNR numbers 6600 to 6623 were the six locomotives that the Cape Government Railways received from Baldwin in 1897. The order came about because the CGR could not order from the British manufacturers as usual due to strikes and Baldwin had already developed a locomotive that largely met the requirements. Only the heating surface was slightly enlarged and the locomotive had to be converted to South African Johnston couplers, which is why a lower purchase price could be offered. They were assigned to class 4, which also included 4-6-0 locomotives.
It is said that the chief engineer of the CGR, H.M. Beatty, was impressed by the robust construction and he valued the merits of the bar frame so much that his later designs also all got a bar frame. After the founding of the South African Union in 1910 and the merger of the railway administrations, it became apparent, as with the Japanese sisters, that the locomotives had too little adhesive weight to reliably start heavy trains. They were therefore classified as obsolete, but remained in use on their home line until 1931.
Technical data
General
- Built
- 1897
- Manufacturers
- Baldwin
- Wheel arrangement
- 4-4-2 (Atlantic)
- Gauge
- 1,067 mm (Cape gauge)
Dimensions and weights
- Length
- 16.29 m
- Wheelbase
- 6.86 m
- Total wheelbase
- 14.01 m
- Service mass
- 45.5 t
- Adhesion mass
- 24.1 t
- Total mass
- 76.1 t
- Rigid wheelbase
- 1.83 m
- Axle load
- 12.3 t
- Water capacity
- 10,910 l
- Fuel capacity
- 5.8 t (coal)
Boiler
- Grate area
- 2.787 m²
- Firebox surface
- 9.105 m²
- Tube heating surface
- 135.824 m²
- Evaporative heating surface
- 144.929 m²
- Total heating surface
- 144.9 m²
Power plant
- Driver diameter
- 1,422 mm
- Boiler pressure
- 12.4 bar
- Expansion type
- simple expansion
- Cylinders
- two, 406 x 559 mm
Power
- Power source
- steam
- Estimated power
- 597 kW (812 PS)
- Starting effort
- 68.4 kN
Calculated values
- Factor of adhesion
- 1 : 3.46
- Optimal speed
- 53 km/h
- Power-to-weight ratio
- 13.1 kW/t
- Heating Surface Equivalent
- 190.5 m²
- Cylinder volume/HSE
- 1 : 761.19
- Adhesive weight/Total
- 1 : 1.89
- Tractive force/Heating surface
- 1 : 9.86
- Grate area/Heating surface
- 1 : 52.00
- Firebox/Tube surface
- 1 : 14.92