Data from D Rock Carling, 4-8-0 Tender Locomotives (New York: Drake Publishers, Inc, 1972), p. 68.
Uganda Railways came late to the notion of a Twelve-wheeler layout, purchasing this set of saturated-boiler locomotives in 1914 designed by builder Nasmyth Wilson.
Apparently pleased with the result, the UR had to wait until World War One ended to put in a production order for 34 locomotives with Glasgow-based North British Locomotive Company. Designated GB, the postwar locomotives featured only minor changes.
(To test the concept of superheated boilers, Nasmyth Wilson produced two superheated prototypes; see Locobase 20636.)
Altogether, the 41 locomotives were certainly useful, although none was ever superheated. The pre-war septet was scrapped in 1934. Vulcans served the UR through the 1930s and 1940s. Six survived to be taken in the East African Railways in 1948.
Data from D Rock Carling, 4-8-0 Tender Locomotives (New York: Drake Publishers, Inc, 1972), p. 68. Works numbers were L 1350-L 1351 in 1920.
Nasmyth Wilson and North British Locomotive Company produced 41 Twelve-wheelers with saturated boilers in 1914 and 1919 (Locobase 20637) for the UR. Then the railway decided to test a superheated variation of the basic design and NW supplied two prototypes. Carling wrote that extensive trials proved that superheating the boiler would confer sizable benefits
A larger version went into production in significant numbers; see Locobase 4371.
Meanwhile, the two prototypes only ran for about 13 years before being scrapped in 1934 together with the original G class engines.
Data from D Rock Carling, 4-8-0 Tender Locomotives (New York: Drake Publishers, Inc, 1972), p. 68; "Goods Engine and Tender for the Uganda Railway", Vulcan Foundry Locomotive Catalogue, No. 36, found on Flicker's Historical Locomotive Images website at []; +and "Metre Gauge Eight-Coupled Engines for the Uganda Railway", Locomotive Magazine, Volume XXIX [29] (14 April 1923), p. 96 . See also the Nairobi museum website [
] (first accessed November 2002).(Many thanks to Jorge Cerezo Toledo for his 26 June 2021 email containing links to several sites including the Vulcan Catalogue referred to above.) Vulcan Foundry works numbers were 3556-3560 in 1922, 3578-3592 in 1923, 3788-3805, 3863-3880 in 1925. Nasmyth Wilson added six more in 1930 as works numbers 1580-1585.
This Belpaire-firebox class were obtained to deal with an increase in heavy goods traffic after World War I. Trials with two prototypes (Locobase 20636) were successful, showing that superheating the boiler would confer sizable benefits.
After Vulcan Foundry enlarged most of the dimensions, the UR bought the class in significant numbers. When the KUR was absorbed by East African Railways, these Twelve-Wheelers became Class 24 and were numbered 2401-2462.
Principal Dimensions by Steve Llanso of Middle Run Media | |||
---|---|---|---|
Class | G/GA, GB/EB, EB1/22 | GC | GD/24 |
Locobase ID | 20637 | 20636 | 4371 |
Railroad | Kenya-Uganda Railway | Kenya-Uganda Railway | Kenya-Uganda Railway |
Country | Kenya | Kenya | Kenya |
Whyte | 4-8-0 | 4-8-0 | 4-8-0 |
Number in Class | 41 | 2 | 62 |
Road Numbers | 121-161 | 119-120 | 162-223/2401-2462 |
Gauge | Metre | Metre | Metre |
Number Built | 41 | 2 | 62 |
Builder | Nasmyth Wilson | Nasmyth Wilson | Several |
Year | 1914 | 1920 | 1923 |
Valve Gear | Walschaert | Walschaert | Walschaert |
Locomotive Length and Weight | |||
Driver Wheelbase (ft / m) | 12 / 3.66 | 12 / 3.66 | 12.25 / 3.73 |
Engine Wheelbase (ft / m) | 21.25 / 6.48 | 21.25 / 6.48 | 21.42 / 6.53 |
Ratio of driving wheelbase to overall engine wheelbase | 0.56 | 0.56 | 0.57 |
Overall Wheelbase (engine & tender) (ft / m) | 45.62 / 13.90 | 42.23 / 12.87 | 44.94 / 13.70 |
Axle Loading (Maximum Weight per Axle) (lbs / kg) | |||
Weight on Drivers (lbs / kg) | 77,728 / 35,257 | 74,928 / 33,987 | 88,480 / 40,134 |
Engine Weight (lbs / kg) | 95,984 / 43,538 | 96,096 / 43,588 | 105,840 / 48,008 |
Tender Loaded Weight (lbs / kg) | 62,496 / 28,348 | 62,496 / 28,348 | 71,680 / 32,514 |
Total Engine and Tender Weight (lbs / kg) | 158,480 / 71,886 | 158,592 / 71,936 | 177,520 / 80,522 |
Tender Water Capacity (gals / ML) | 2140 / 8.11 | 3000 / 11.36 | 3000 / 11.36 |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 6 / 6 | 4.50 / 4 | 6.50 / 6 |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 32 / 16 | 31 / 15.50 | 37 / 18.50 |
Geometry Relating to Tractive Effort | |||
Driver Diameter (in / mm) | 43 / 1092 | 43 / 1092 | 43 / 1092 |
Boiler Pressure (psi / kPa) | 180 / 1240 | 160 / 1100 | 165 / 1140 |
High Pressure Cylinders (dia x stroke) (in / mm) | 16" x 22" / 406x559 | 17" x 22" / 432x559 | 18" x 22" / 457x559 |
Tractive Effort (lbs / kg) | 20,039 / 9089.55 | 20,109 / 9121.30 | 23,249 / 10545.58 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.88 | 3.73 | 3.81 |
Heating Ability | |||
Tubes (number - dia) (in / mm) | 128 - 1.75" / 44 | ||
Flues (number - dia) (in / mm) | 18 - 5.25" / 133 | ||
Flue/Tube length (ft / m) | 10.79 / 3.29 | ||
Firebox Area (sq ft / m2) | 126 / 11.71 | 126 / 11.71 | 140 / 13.01 |
Grate Area (sq ft / m2) | 17.50 / 1.63 | 17.10 / 1.59 | 18 / 1.67 |
Evaporative Heating Surface (sq ft / m2) | 1173 / 108.98 | 850 / 78.97 | 1032 / 95.88 |
Superheating Surface (sq ft / m2) | 167 / 15.51 | 152 / 14.12 | |
Combined Heating Surface (sq ft / m2) | 1173 / 108.98 | 1017 / 94.48 | 1184 / 110 |
Evaporative Heating Surface/Cylinder Volume | 229.12 | 147.07 | 159.27 |
Computations Relating to Power Output (More Information) | |||
Robert LeMassena's Power Computation | 3150 | 2736 | 2970 |
Same as above plus superheater percentage | 3150 | 3174 | 3356 |
Same as above but substitute firebox area for grate area | 22,680 | 23,386 | 26,103 |
Power L1 | 4543 | 5918 | 5657 |
Power MT | 515.42 | 696.51 | 563.81 |