Cape Government / Cape Government Railways 2-8-0 Locomotives in South_Africa


Class Details by Steve Llanso of Sweat House Media

Class 804/Class Experimental 3 (Locobase 21140)

Data from "South African Class Experimental 3 2-8-0" in Wikipedia at [], last accessed 30 July 2023. (Thanks to Alexander Blessing for his 12 July 2023 email pointing all the data differences between this compound and the other fifteen simple-expansion stablemates.) Works number was 28638 in December 1903.

Locobase 20549 describes the one Experimental 2 2-8-0 tandem-compound delivered to the CGR in 1902. H M Beatty, the CGR's Chief Locomotive Superintendent, clearly anticipated benefits from the compounding system, but apparently concluded that the heating ratios between grate and boiler weren't quite correct. So he ordered another test engine with a significantly enlarged grate in a much shallower firebox. Yet the design's weirdly high compounding ratio remained unchanged at 3.13 and all of the problems with maintenance access and leaks remained u nsolved.

Alas for whatever hopes he might have nurtured, the 859 performed no better than the 804. Yet the Experimental 3's changes may have provided enough power (or Beatty was indifferent to its current usability) for it to remain a tandem compound until it was sold in 1920 to the Transvaal and Natal Collieries.


Class 804/Class Experimental 2 (Locobase 20549)

Data from "Tandem Compound Consolidation Locomotive for the Cape Government Railroads, South Africa", Railroad Gazette, Volume 35, No 2 (9 January 1903), p. 23; and "A Narrow Gauge Tandem Compound Locomotive for South Africa", Railway and Engineering Review, Volume 43, No 1 (3 January 1903), pp 2-3. See also "South African Class Experimental 2 2-8-0" in Wikipedia at [], last accessed 30 July 2023. (Thanks to Alexander Blessing for his 12 July 2023 email pointing all the data differences between this compound and the other fifteen simple-expansion stablemates.) Works number was 26694 in October 1902.

Locobase 10428 notes that the CGR bought very few Consolidations, so it's a bit of a surprise to see that one of those was this tandem compound. It was the first such compound--one which had the LP cylinder on each side took steam from the HP cylinder directly in front of it--to be built for the narrow gauge, said RG. Wikipedia observed that Chief Locomotive Superintendent H M Beatty investigated several 2-8-0 variants to address the extreme shortage of tractive power in his existing engines.

Based on the earlier Schenectady design, its layout must have offered a better option for fitting four cylinders on such a narrow frame than the other variants, which spread the cylinders out across and under the smokebox. Locobase suspects that the limited space available even in the new arrangement--which presented a high 3.13 compounding ratio-- meant that the HP cylinders couldn't deliver enough steam to fill adequately the oversized LP cans just behind.

Its status as a "one-off" suggests the outcome of this experiment and few other narrow-gauge tandem compounds would be built for anyone. Wikipedia details the many difficulties crews and depots encountered with this lone experiment. "[C]onsiderable trouble was experienced with the tandem arrangement since the piston rod packing between the high- and low-pressure cylinders could not be inspected or serviced without removing the high-pressure cylinders. Lubrication of the packing bushes also proved difficult, with the result that the piston rods wore rapidly. In addition, as a result of high levels of condensation, the low-pressure cylinders were inefficient since the drain cocks had to be opened frequently enough to detract from the locomotive's otherwise good performance."

Before long, Beatty gave up and converted the 804 to run as an additional 8X simple-expansion engine. Its short career ended with its disposal in 1916.


Class 8X (Locobase 10428)

Data from "Tandem Compound Consolidation Locomotive for the South African Railways", Railroad Gazette, Volume XXXV [35], No 2 (9 January 1903, p. 23. See also Locomotive Magazine: "The Cape to Cairo Railway", Vol IX (26 December 1903), p. 372, the SAR steam's website [], last accessed 28 May 2009 and Wikipedia's entry on the 8X. Schenectady works numbers were 564-5645 (before Alco) and 25453-25459, 25446-25452.

This was considered a "heavy" Consolidation for the Cape gauge at the time it went into service in 1901. The CGR and its successor South African Railways would buy few 2-8-0s, preferring instead to lead with a bogie on its 4-8-0s.


Class 8Y (Locobase 12429)

Data from Wikipedia's entry on the 8Y. Kitson works numbers were 4198-4201.

Following on the heels of the Schenectady Consolidations (Locobase 10428), this quartet sported a new boiler and firebox that was higher and wider. The result was more evaporative heating surface area and 50% more grate area, but less firebox heating surface.

The class served the CGR and the SAR until 1938.


Class 8Z (Locobase 12430)

Data from Wikipedia's entry on the 8Y. NBL works numbers were 16095-16102.

For this octet of Consolidations, the CGR ordered slightly larger versions of the Kitson locomotives delivered the year before (Locobase 12429).

The Wikipedia entry has some inconsistencies. Locobase suspects that the tube count is correct as it is similar to the *X and 8Y and the boiler's diameter is the same. The only way to account for the growth in heating surface is to assume the tube length grew by about a foot and that is the estimate that the compiler uses.

Operating in the Western Cape Region (and some in Orange Free State), the class remained in service until 1935.

NB: Tube length is an estimate based on the calculation of tube surface area by subtracting reported firebox heating surface from reported total evaporative heating surface

Principal Dimensions by Steve Llanso of Sweat House Media

Class804/Class Experimental 3804/Class Experimental 28X8Y8Z
Locobase ID21140 20549 10428 12429 12430
RailroadCape Government Railways (SAR)Cape Government Railways (SAR)Cape Government Railways (SAR)Cape Government Railways (SAR)Cape Government (SAR)
CountrySouth AfricaSouth AfricaSouth AfricaSouth AfricaSouth Africa
Whyte2-8-02-8-02-8-02-8-02-8-0
Number in Class111648
Road Numbers839/909804749-757 & 351-357/880-895817-820 / 896-899821-828 / 900-907
Gauge3'6"3'6"3'6"3'6"3'6"
Number Built111548
BuilderAlco-SchenectadyAlco-SchenectadyAlco-SchenectadyKitson & CoNorth British
Year19031902190119031904
Valve GearStephensonStephensonWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)14.50 / 4.4214.50 / 4.42
Engine Wheelbase (ft / m)22.17 / 6.7622.17 / 6.7621.60 / 6.5821.60 / 6.5821.60 / 6.58
Ratio of driving wheelbase to overall engine wheelbase 0.65 0.65
Overall Wheelbase (engine & tender) (ft / m)46.42 / 14.1546.88 / 14.2946.87 / 14.2946.87 / 14.2946.87 / 14.29
Axle Loading (Maximum Weight per Axle) (lbs / kg)31,350 / 14,22031,350 / 14,22027,328 / 12,39627,77629,120 / 13,209
Weight on Drivers (lbs / kg)118,496 / 53,749102,480 / 46,484102,480 / 46,484102,480 / 46,48492,736 / 42,064
Engine Weight (lbs / kg)134,288 / 60,912115,809 / 52,530115,808 / 52,530115,808 / 52,530126,336 / 57,305
Tender Loaded Weight (lbs / kg)82,321 / 37,34082,321 / 37,34082,320 / 37,34093,184 / 37,34093,184 / 42,268
Total Engine and Tender Weight (lbs / kg)216,609 / 98,252198,130 / 89,870198,128 / 89,870208,992 / 89,870219,520 / 99,573
Tender Water Capacity (gals / ML)3700 / 14.023699 / 14.013699 / 14.013080 / 11.673429 / 12.99
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 6.60 / 6 6.60 / 6 6.60 / 6 6.60 / 611 / 10
Minimum weight of rail (calculated) (lb/yd / kg/m)49 / 24.5043 / 21.5043 / 21.5043 / 21.5039 / 19.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)48 / 121948 / 121948 / 121948 / 121948 / 1219
Boiler Pressure (psi / kPa)200 / 13.80179.80 / 12.40180 / 12.40180 / 12.40180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)13" x 26" / 330x66013" x 26" / 330x66018.5" x 24" / 470x61018.5" x 24" / 470x61018.5" x 24" / 470x610
Low Pressure Cylinders (dia x stroke) (in / mm)23" x 26" / 584x66023" x 26" / 584x660
Tractive Effort (lbs / kg)23,588 / 10699.3521,206 / 9618.8926,182 / 11875.9726,182 / 11875.9726,182 / 11875.97
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.02 4.83 3.91 3.91 3.54
Heating Ability
Tubes (number - dia) (in / mm)200 - 2.008" / 51196 - 2.008" / 51194 - 2" / 51196 - 2" / 51194 - 2" / 51
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)12.45 / 3.7912.53 / 3.8212.54 / 3.8212.54 / 3.8213.50 / 4.11
Firebox Area (sq ft / m2)107 / 9.94128.95 / 11.98129 / 11.98105 / 9.76106 / 9.85
Grate Area (sq ft / m2)31.30 / 2.9119.81 / 1.8419.80 / 1.8430.90 / 2.8732 / 2.97
Evaporative Heating Surface (sq ft / m2)1413 / 131.271396 / 129.691396 / 129.691417 / 131.691461 / 135.78
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1413 / 131.271396 / 129.691396 / 129.691417 / 131.691461 / 135.78
Evaporative Heating Surface/Cylinder Volume353.76349.50186.96189.78195.67
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation62603562356455625760
Same as above plus superheater percentage62603562356455625760
Same as above but substitute firebox area for grate area21,40023,18523,22018,90019,080
Power L124932348393637453840
Power MT185.53202.05338.70322.26365.15

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