Sierra Leone Development Corp. Beyer-Garratt Locomotives in Sierra_Leone

Class Details by Steve Llanso of Sweat House Media

Class 3 (Locobase 742)

Data from Gavin Hamilton's excellent compilation of Garratt data posted at [] . (6 September 2005). See also "Marampa Mines Railway, Sierra Leone", Sierra Leone National Railway Museum at []; and "Sierra Leone", on the Derby Sulzer (diesel-electric) website at [], both last accessed 17 August 2021. Works numbers were 6726-6727, 6786, and 6842 in 1937.

Sierra Leone's National Railway Museum's account and that of the Derby Sulzer company start with the discovery of hard lateritic hematite ore in the Marampa region by a Gold Coast Geological Survey geologist N R Junner. Later assays estimated the deposit held about 12 million ton of ore. By 1930 several interested parties had formed the Sierra Leone Development Corporation (DELCO) to construct a Cape Gauge (3 ft 6 in - 1,067 mm) railway and port linking Marampa to the coast in the estuary on which the future capital of Freetown would be located.

84 km (52 miles) of rail built to allow an axle loading of 13 tons linked Pepel to Marampa, passing through Lunsar, Rogbere, Moria, Borup and Lungi Loi. The ore traveled down river on a ruling grade of 1 in 125 (0.8%) and an inbound and empty alignment with a ruling grade pitched to a maximum of 1 in 57 (1.75%)

The line opened in 1933 with two Beyer-Garratt locomotives hauling the ore trains. Two more were acquired in 1935 and 1937 respectively. The design followed the classic Beyer-Garratt formula of power unit-boiler and Belpair firebox-power unit using a superheater, piston valves actuated by outside constant-lead radial valve gear. Their dimensions closely matched those of the South African Railways GE basic-minerals engine (Locobase 4382).

The class remained the primary prime movers for more than 20 years before being replaced by diesels in 1955. (The Derby Selzer website's account includes a "footnote": [T]he first President of Sierra Leone, Siaka Stevens, started work on the construction of the railway for DELCO in 1931 and later became a station master and stenographer at Marampa until 1946."

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID742
RailroadSierra Leone Development Corp.
CountrySierra Leone
Number in Class4
Road Numbers3-6
Number Built4
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)29,120 / 13,209
Weight on Drivers (lbs / kg)232,064 / 105,263
Engine Weight (lbs / kg)338,240 / 153,423
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)338,240 / 153,423
Tender Water Capacity (gals / ML)5520 / 20.91
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 9.90 / 9
Minimum weight of rail (calculated) (lb/yd / kg/m)48 / 24
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)45.50 / 1156
Boiler Pressure (psi / kPa)180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)18" x 24" / 457x610 (4)
Tractive Effort (lbs / kg)52,296 / 23721.09
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.44
Heating Ability
Tubes (number - dia) (in / mm)
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)
Firebox Area (sq ft / m2)224 / 20.81
Grate Area (sq ft / m2)51.50 / 4.78
Evaporative Heating Surface (sq ft / m2)2590 / 240.62
Superheating Surface (sq ft / m2)370 / 34.37
Combined Heating Surface (sq ft / m2)2960 / 274.99
Evaporative Heating Surface/Cylinder Volume183.21
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation9270
Same as above plus superheater percentage10,475
Same as above but substitute firebox area for grate area45,562
Power L16797
Power MT516.57

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