The reference for locomotives and railcars
South African classes GMA and GMAM
South Africa | 1953 | 120 produced
GMAM No. 4079 in September 2006 at Capital Park, Pretoria
GMAM No. 4079 in September 2006 at Capital Park, Pretoria
Col André Kritzinger
flickr/Historical Railway Images
ManufacturerHenschel, Beyer, Peacock & Co., North British
Axle config4-8-2+2-8-4T (Double Mountain (Garratt)) 
Gauge3 ft 6 in (Cape gauge)
Dimensions and Weights
Length93 ft 10 in
Wheelbase30 ft 4 in
Fixed wheelbase14 ft 5 in
Total wheelbase86 ft 4 in
Service weight419,000 lbs428,800 lbs
Adhesive weight268,750 lbs273,600 lbs
Axle load34,400 lbs35,165 lbs
Water capacity10,136 us gal10,676 us gal
Fuel capacity25,984 lbs (coal)31,360 lbs (coal)
Power sourcesteam
Estimated power2,175 hp (1,622 kW)
Optimal speed20 mph
Starting effort68,796 lbf
Power Plant
Driver diameter54 in
Boiler pressure200 psi
Expansion typesimple
Cylindersfour, 20 1/2 x 26 in
Grate area63.2 sq ft
Firebox area237.2 sq ft
Tube heating area2,973.8 sq ft
Evaporative heating area3,211 sq ft
Superheater area747 sq ft
Total heating area3,958 sq ft
Calculated Values
steam locomotive
last changed: 03 2024

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