The reference for locomotives and railcars


Page views since 2023-01-26: 310042
South African class 12A
South Africa | 1919 | 75 produced
No. 1548 on a Henschel works photo
No. 1548 on a Henschel works photo
collection Leith Paxton
Variant12Arebuilt 12AR
ManufacturerNorth British, Henschel
Axle config4-8-2 (Mountain) 
Gauge3 ft 6 in (Cape gauge)
Dimensions and Weights
Length66 ft 11 5/8 in69 ft 7 in
Wheelbase32 ft 1 in
Fixed wheelbase13 ft 6 in
Total wheelbase58 ft 7 1/4 in61 ft 7 3/8 in
Service weight221,785 lbs222,226 lbs
Adhesive weight154,897 lbs154,456 lbs
Total weight336,205 lbs370,156 lbs
Axle load38,757 lbs38,978 lbs
Water capacity5,104 us gal7,206 us gal
Fuel capacity22,400 lbs (coal)26,880 lbs (coal)
Power sourcesteam
Estimated power1,300 hp (969 kW)
Optimal speed17 mph
Starting effort47,424 lbf
Power Plant
Driver diameter51 in
Boiler pressure190 psi
Expansion typesimple
Cylinderstwo, 24 x 26 in
Grate area40.5 sq ft41 sq ft
Firebox area209 sq ft164 sq ft
Tube heating area2,301 sq ft2,338 sq ft
Evaporative heating area2,510 sq ft2,502 sq ft
Superheater area466 sq ft480 sq ft
Total heating area2,976 sq ft2,982 sq ft
Calculated Values
steam locomotive
last changed: 09 2023

We use cookies to save the following settings:

  • selected navigation structure
  • selected language
  • preferred units
  • spelling of railway company names

If you refuse the use of cookies, the settings will only be retained for the current session and will be reset to the default values the next time you visit the site.

Display of units

Here you can set the desired unit system for the technical data.

  • Metric: Lengths in meters, weights in tonnes, and volumes in cubic meters
  • Imperial (UK): Lengths in feet/inches, weights in long tons and volumes in imperial gallons
  • Imperial (US): Lengths in feet/inches, weights in pounds, and volumes in US gallons
  • Individual: Depends on the country of origin of each locomotive
Operator names

Here you can set the display of railway company names.

  • Short: Abbreviation or short form of the name
  • Standard: commonly used name, partially translated to English
  • Complete: full name in local language