Walvis Bay 2-4-2 Locomotives in South_Africa

Class Details by Steve Llanso of Sweat House Media

Class Hope (Locobase 9977)

Data from Pieter Conradie's blog at [], last accessed 10 March 2009.

The author of this blog says the Kerr, Stuart design (works #652) was based on the SIRDAR type 0-4-0T, but HOPE was modified because of the low track loading - 12 lb/yard - to spread the weight over two more axles. (Gives the reader an idea of just what light rail they were using.) Its running gear was protected from debris by drop-down skirts. Conradie does not give the stroke in his otherwise reasonably full set of specs, so Locobase adopted 10" from another, very similar K, S locomotive.

Even with two more axles, the HOPE seems to have been too heavy and in any event German shippers preferred Swakopmund harbor sent the WB railway into desuetude before World War I. Remarkably, HOPE was not cut up and has been preserved.

NB: The direct heating surface (including the firebox heating surface) is an estimate calculated by subtracting the calculated tube heating surface from the reported total evaporative heating surface.

Principal Dimensions by Steve Llanso of Middle Run Media

Locobase ID9977
RailroadWalvis Bay
CountrySouth Africa
Number in Class1
Road Numbers
Number Built1
BuilderKerr, Stuart & Co
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)
Engine Wheelbase (ft / m)
Ratio of driving wheelbase to overall engine wheelbase
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)3920 / 1778
Weight on Drivers (lbs / kg)
Engine Weight (lbs / kg)12,000 / 5443
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)12,000 / 5443
Tender Water Capacity (gals / ML)120 / 0.45
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 0.30 / 0.30
Minimum weight of rail (calculated) (lb/yd / kg/m)
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)24 / 610
Boiler Pressure (psi / kPa)120 / 8.30
High Pressure Cylinders (dia x stroke) (in / mm)6" x 10" / 152x254
Tractive Effort (lbs / kg)1530 / 694.00
Factor of Adhesion (Weight on Drivers/Tractive Effort)
Heating Ability
Tubes (number - dia) (in / mm)36 - 1.75" / 44
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m) 5.08 / 1.55
Firebox Area (sq ft / m2)19 / 1.77
Grate Area (sq ft / m2) 3.50 / 0.33
Evaporative Heating Surface (sq ft / m2)102 / 9.48
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)102 / 9.48
Evaporative Heating Surface/Cylinder Volume311.69
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation420
Same as above plus superheater percentage420
Same as above but substitute firebox area for grate area2280
Power L12890
Power MT

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