Sudan Railways Beyer-Garratt Locomotives in Sudan

Class Details by Steve Llanso of Sweat House Media

Class 250/17th class (Locobase 788)

Data from A E Durrant, The Smoke That Thunders (Harare, Zimbabwe: African Publishing Group, 1997), pp. 156-157. Works numbers were 6798-6801 in 1936 and 6870-6875 in 1937.

Double Hudson Garratts that ultimately operated in several African countries. The first batch for Sudan sought to combine the Garratt concept's combination of light axle loading, good power and boiler capacity, and flexibility along tight alignments. According to Durrant, the class faced conditions they couldn't handle. "Track was 'ballasted' with indigenous sand, and in the days before widespread use of roller bearings, the dust kicked up by the leading engine unit played havoc with the bearings of the following unit."

Rhodesia procured the set in 1950, but they didn't really fit in well among the 14th and 15th classes because of their power to grate area imbalance. Moreover, the cabs were "stuffy" and inadequately ventilated.

Too big to work as shunters, too underpowered to handle several key freight lines, the class "provided disappointing results", says Durrant.

After being retired from Rhodesian service in1963-1964, all of the class were sold to Mozambique's CFM Estado in 1964-1965. There they operated for another ten years on the Beira-Vila Machado section.

Principal Dimensions by Steve Llanso of Sweat House Media

Class250/17th class
Locobase ID788
RailroadSudan Railways
Number in Class10
Road Numbers250-259100-109/271-279/921-930
Number Built10
BuilderBeyer, Peacock
Valve GearWalschaert
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)28,000 / 12,701
Weight on Drivers (lbs / kg)167,104 / 75,797
Engine Weight (lbs / kg)378,112 / 171,509
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)378,112 / 171,509
Tender Water Capacity (gals / ML)8400 / 31.82
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)11 / 10
Minimum weight of rail (calculated) (lb/yd / kg/m)46 / 23
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)57 / 1448
Boiler Pressure (psi / kPa)200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)16.75" x 26" / 425x660 (4)
Tractive Effort (lbs / kg)43,512 / 19736.73
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.84
Heating Ability
Tubes (number - dia) (in / mm)
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)12.42
Firebox Area (sq ft / m2)184 / 17.10
Grate Area (sq ft / m2)43.20 / 4.01
Evaporative Heating Surface (sq ft / m2)1960 / 182.16
Superheating Surface (sq ft / m2)440 / 40.89
Combined Heating Surface (sq ft / m2)2400 / 223.05
Evaporative Heating Surface/Cylinder Volume147.79
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation8640
Same as above plus superheater percentage10,195
Same as above but substitute firebox area for grate area43,424
Power L19799
Power MT775.68

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