Data from "Recent Designs of Twelve-Wheel Locomotives", Railway Age, Volume 71, No 6 (6 August 1921), pp. 251-252 and DeGolyer, Volume 63, pp. 112 1/2[sic]. See also Peter Ball, "Benguela - More than just a current" posted 17 November 2015 on the South Africa Heritage Sector's Heritage Portal website at [], last accessed 18 September 2021; and Harri Makinen et.al., "Comparison of the Growth of Six Eucalyptus Species in Angola", International Journal of Forestry Resarch, Volume 2011 | Article ID 980259 at [
], last accessed 9 March 2023. Baldwin's works numbers were 54017-54018 in November 1920.
These Twelve-wheelers operated in general service. They presented lots of tube cross-section for the grate they used. Ten inch (254 mm) piston valves fed the cylinders.
The Harri Makinen paper notes the Benguela originally felled Brachystegia trees from the local miombo region for its locomotive fuel, but quickly exhausted the supply. They then adopted several fast-growing eucalyptus species grown in special plantations; eucalyptus saligna proved to gain 40 cu m per hectare (589 cu ft/acre) per year. .
Peter Ball pointed out a key characteristic of the fuel compared to coal. He noted that while ton for ton, a eucalyptus log had as much heat value as coal, "in terms of heat produced per square yard they were five times less effective."
In practical terms, wrote Ball: "his meant that the logs were not only bulkier requiring additional bars being placed on the tenders (to retain the logs that were stacked up to the limit of the loading gauge), but also wooding stops were needed twice as often as would be the case for coaling stops. It also took two firemen to add the fuel to the fire!"
The railway had curves with radii as small as 90 metres (295 feet) or 19 1/2 degrees. Grades on the adhesion section were no greater than 1 in 44 (0.8%).
Data from "Benguella [sic] Ry", The Locomotive, Volume XVI [16] (15 July 1910). p 153. See also D[ennis] Rock Carling, 4-8-0 Tender Locomotives (New York: Drake Publishers, Inc, 1972), p. 81 and serial 253 on table XIII [13], pp.106-107.
Carling wrote that this pair of wood burning Twelve-wheelers, although placed in the 8th Class, was more like the Cape "Experimental 6" rather than the South African Cape 8th class locomotive.
Principal Dimensions by Steve Llanso of Middle Run Media | ||
---|---|---|
Class | 192 | 8th class |
Locobase ID | 2860 | 15965 |
Railroad | Benguela Railway | Benguela Railway |
Country | Angola | Angola |
Whyte | 4-8-0 | 4-8-0 |
Number in Class | 2 | 2 |
Road Numbers | 192-193/215-216 | 130-131 |
Gauge | 3'6" | 3'6" |
Number Built | 2 | 2 |
Builder | Baldwin | Kitson & Co |
Year | 1920 | 1910 |
Valve Gear | Walschaert | Walschaert |
Locomotive Length and Weight | ||
Driver Wheelbase (ft / m) | 13.50 / 4.11 | 13.50 / 4.11 |
Engine Wheelbase (ft / m) | 23.33 / 7.11 | 23.33 / 7.11 |
Ratio of driving wheelbase to overall engine wheelbase | 0.58 | 0.58 |
Overall Wheelbase (engine & tender) (ft / m) | 50.46 / 15.38 | 50.46 / 15.38 |
Axle Loading (Maximum Weight per Axle) (lbs / kg) | 29,120 / 13,209 | 29,120 / 13,209 |
Weight on Drivers (lbs / kg) | 106,900 / 48,489 | 107,184 |
Engine Weight (lbs / kg) | 137,000 / 62,142 | 135,184 |
Tender Loaded Weight (lbs / kg) | 90,000 / 40,823 | 90,048 |
Total Engine and Tender Weight (lbs / kg) | 227,000 / 102,965 | 225,232 |
Tender Water Capacity (gals / ML) | 4200 / 15.91 | 3600 / 13.64 |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 540 / 2043.90 | 8.25 / 8 |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 45 / 22.50 | 45 / 22.50 |
Geometry Relating to Tractive Effort | ||
Driver Diameter (in / mm) | 48 / 1219 | 48 / 1219 |
Boiler Pressure (psi / kPa) | 162.40 / 1120 | 180 / 1240 |
High Pressure Cylinders (dia x stroke) (in / mm) | 20" x 24" / 508x610 | 20" x 24" / 508x610 |
Tractive Effort (lbs / kg) | 27,608 / 12522.79 | 30,600 / 13879.94 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.87 | 3.50 |
Heating Ability | ||
Tubes (number - dia) (in / mm) | 127 - 2" / 51 | 236 - 1.875" / 48 |
Flues (number - dia) (in / mm) | 21 - 5.375" / 137 | |
Flue/Tube length (ft / m) | 13.50 / 4.11 | 12 / 3.66 |
Firebox Area (sq ft / m2) | 130 / 12.08 | 117 / 10.87 |
Grate Area (sq ft / m2) | 18.70 / 1.74 | 29 |
Evaporative Heating Surface (sq ft / m2) | 1418 / 131.74 | 1507 / 140 |
Superheating Surface (sq ft / m2) | 334 / 31.03 | |
Combined Heating Surface (sq ft / m2) | 1752 / 162.77 | 1507 / 140 |
Evaporative Heating Surface/Cylinder Volume | 162.49 | 172.69 |
Computations Relating to Power Output (More Information) | ||
Robert LeMassena's Power Computation | 3037 | 5220 |
Same as above plus superheater percentage | 3614 | 5220 |
Same as above but substitute firebox area for grate area | 25,123 | 21,060 |
Power L1 | 7554 | 3452 |
Power MT | 623.15 | 284.01 |