Cape Government 2-8-2 Locomotives in South_Africa

Class Details by Steve Llanso of Sweat House Media

Class EXP4 (Locobase 9930)

Ben H Morgan, Report on the Engineering Trades of South Africa (London: P S King & Son, 1902), , p. 67, accessed through [] and R H Clatworthy, "Beatty's Locomotives",accessed at []

Morgan notes that this design was under construction by an English builder, but gave no more context. Clatworthy fills in the facts that this pair was ordered by Hazlett M Beatty (Kitson works #4195-4196). Morgan's diagram shows 18.5" x 24" cylinders, but Locobase suspects they gained the half-inch before delivery.

Holland gives the boiler areas shown in the specs; earlier sources gave a total evaporative heating surface of 1,615 sq ft and 109 sq ft in the firebox.

They were small and low-drivered by CGR (and SAR) standards. Holland comments that the attempt to combine the good qualities of the Class 8s with a wide firebox did not ultimately succeed because of high maaintenance costs. It's also clear that these were among the few Mikados ever bought by the CGR or its successor, the South African Railways. They were never superheated.

A later locomotive - the 9th Class -- was an enlargement delivered by Kitson in 1906.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID9930
RailroadCape Government
CountrySouth Africa
Number in Class2
Road Numbers805-806 / 910-911
Number Built2
BuilderKitson & Co
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)13.33 / 4.06
Engine Wheelbase (ft / m)26.75 / 8.15
Ratio of driving wheelbase to overall engine wheelbase 0.50
Overall Wheelbase (engine & tender) (ft / m)50.60 / 15.42
Axle Loading (Maximum Weight per Axle) (lbs / kg)28,480 / 12,918
Weight on Drivers (lbs / kg)109,536 / 49,685
Engine Weight (lbs / kg)144,144 / 65,383
Tender Loaded Weight (lbs / kg)82,432 / 37,391
Total Engine and Tender Weight (lbs / kg)226,576 / 102,774
Tender Water Capacity (gals / ML)3426 / 12.98
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 6.60 / 6
Minimum weight of rail (calculated) (lb/yd / kg/m)46 / 23
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)48 / 1219
Boiler Pressure (psi / kPa)180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)19" x 24" / 483x610
Tractive Effort (lbs / kg)27,617 / 12526.88
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.97
Heating Ability
Tubes (number - dia) (in / mm)159 - 2.25" / 57
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)14.91 / 4.54
Firebox Area (sq ft / m2)117.30 / 10.90
Grate Area (sq ft / m2)26.75 / 2.49
Evaporative Heating Surface (sq ft / m2)1508 / 140.15
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1508 / 140.15
Evaporative Heating Surface/Cylinder Volume191.47
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation4815
Same as above plus superheater percentage4815
Same as above but substitute firebox area for grate area21,114
Power L13830
Power MT308.34

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