Natal Navigation Colliery Beyer-Garratt Locomotives in South_Africa


Class Details by Steve Llanso of Sweat House Media

Class unknown (Locobase 20932)

Data from "'Garratt' Patent Locomotives for the New Cape Central Railway", Volume XXIX [29] (15 September 1923), p. 256-257; and "Natal Navigation Colliery, Design No.1125", Beyer-Garrrat Patent Articulated Locomotives (Manchester, England: Beyer-Peacock & Company Limited, 1931), archived on flickr's Historical Railway Images at [], et seq, p. 47.. Virtually identical to the Trans-Zambezi locomotives. Works number was 6206 in 1924.

Natal Navigation Collieries and Estate Co purchased an engine that was identical to the New Cape Railway G-class Garratts (Locobase 747) and the Trans-Zambezi Garratts described in Locobase 718 . All had Walschaert gear, piston valves for all four simple-expansion cylinders, a superheater, and a Belpaire firebox.

The NNC locomotive hauled coal trains from the pits to the main line which branched off from Hatting Spruit on the SAR.

Principal Dimensions by Steve Llanso of Sweat House Media

Classunknown
Locobase ID20932
RailroadNatal Navigation Colliery
CountrySouth Africa
Whyte2-6-2+2-6-2
Number in Class1
Road Numbers
Gauge3'6"
Number Built1
BuilderBeyer, Peacock
Year1924
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)16 / 4.88
Engine Wheelbase (ft / m)35.33 / 10.77
Ratio of driving wheelbase to overall engine wheelbase 0.45
Overall Wheelbase (engine & tender) (ft / m)65.25 / 19.89
Axle Loading (Maximum Weight per Axle) (lbs / kg)23,520 / 10,669
Weight on Drivers (lbs / kg)141,120 / 64,011
Engine Weight (lbs / kg)212,404 / 96,345
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)212,404 / 96,345
Tender Water Capacity (gals / ML)3600 / 13.64
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 4.50 / 4.10
Minimum weight of rail (calculated) (lb/yd / kg/m)39 / 19.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)42 / 1067
Boiler Pressure (psi / kPa)180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)15" x 22" / 381x559 (4)
Tractive Effort (lbs / kg)36,064 / 16358.37
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.91
Heating Ability
Tubes (number - dia) (in / mm)225 - 1.75" / 44
Flues (number - dia) (in / mm)24 - 5.5" / 140
Flue/Tube length (ft / m)11.12 / 3.39
Firebox Area (sq ft / m2)157 / 14.59
Grate Area (sq ft / m2)33.90 / 3.15
Evaporative Heating Surface (sq ft / m2)1687 / 156.73
Superheating Surface (sq ft / m2)293 / 27.22
Combined Heating Surface (sq ft / m2)1980 / 183.95
Evaporative Heating Surface/Cylinder Volume187.46
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation6102
Same as above plus superheater percentage7017
Same as above but substitute firebox area for grate area32,499
Power L17153
Power MT670.48

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