Lourenco Marques 4-6-2 Locomotives in Mozambique

Class Details by Steve Llanso of Sweat House Media

Class 301 (Locobase 14728)

Data from DeGolyer, Vol 63, pp. 93+. Works numbers were 52201-52203 in August 1919, 57397-57398 in October 1923.

Although several South African classes and two Japanese classes were bigger than these Portuguese East African engines, they were nonetheless powerful for their gauge and duty.

Firebox heating surface area included 15 sq ft (1.4 sq m) in three arch tubes. Piston valves measured 8" (203 mm) in diameter. One additional feature doubtless welcomed by the drivers: Ragonnet power reverse.

The specifications for these Pacific flyers spelled out the profile over which they were travel and the coal they were to expect to use. Rolling on relatively heavy 80 lb/yard (40 kg/metre) rail along an 89 km (55.3 mile) stretch, the 301s faced gentle minimum curve radii of 300 metres (984 feet) and grades that at most inclined at 1 1/2% and that for only 1,500 metres (0.93 miles). Transvaal coal had an average calorific power that was 83.3% of the best Welsh coal.

Experience with the first three guided the production of the latter two. For example, the staybolt holes bored into the firebox plates in the first batch were not in the same line and were "slantwise", advises the spec for the second batch. "[W]ith vibration and work of loads of locos, they break too frequently."

Stresses on the locomotive contributed to the failure of driving spring hangers, so 304-305 were to get stronger ones.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID14728
RailroadLourenco Marques
Number in Class3
Road Numbers301-303
Number Built3
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)11 / 3.35
Engine Wheelbase (ft / m)29.42 / 8.97
Ratio of driving wheelbase to overall engine wheelbase 0.37
Overall Wheelbase (engine & tender) (ft / m)58.12 / 17.71
Axle Loading (Maximum Weight per Axle) (lbs / kg)33,069
Weight on Drivers (lbs / kg)94,500 / 42,865
Engine Weight (lbs / kg)152,500 / 69,173
Tender Loaded Weight (lbs / kg)106,600 / 48,353
Total Engine and Tender Weight (lbs / kg)259,100 / 117,526
Tender Water Capacity (gals / ML)5300 / 20.08
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)11 / 10
Minimum weight of rail (calculated) (lb/yd / kg/m)53 / 26.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)60 / 1524
Boiler Pressure (psi / kPa)190 / 13.10
High Pressure Cylinders (dia x stroke) (in / mm)18" x 26" / 457x660
Tractive Effort (lbs / kg)22,675 / 10285.22
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.17
Heating Ability
Tubes (number - dia) (in / mm)126 - 2" / 51
Flues (number - dia) (in / mm)21 - 5.375" / 137
Flue/Tube length (ft / m)18 / 5.49
Firebox Area (sq ft / m2)139 / 12.91
Grate Area (sq ft / m2)35.20 / 3.27
Evaporative Heating Surface (sq ft / m2)1851 / 171.96
Superheating Surface (sq ft / m2)456 / 42.36
Combined Heating Surface (sq ft / m2)2307 / 214.32
Evaporative Heating Surface/Cylinder Volume241.72
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation6688
Same as above plus superheater percentage8026
Same as above but substitute firebox area for grate area31,692
Power L116,500
Power MT1154.80

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