East African Railways 2-8-4 Locomotives in Kenya


Class Details by Steve Llanso of Sweat House Media

Class 30 (Locobase 4329)

Some data originally from Dr. Jonathan Smith's data tables at [] . Principal source is "'30' class', East Africa Railways and Harbours Magazine, Volume 2, No 7 (February 1956), p. 236. Works numbers were 27447-27468, 24474-2477 in 1955.

Note that it's a Tribal-class Berkshire, identical to the Class 29 Mikado (Locobase 4330), which had a heavier axle loading. Ziel and Eagleson (1973) show the Belpaire-boilered Berkshire class in its glory. Also see Colin Garratt (Steam Trains of the World, 1987).

According to the museum website [] (November 2002), they were adopted for use on Tanzania's Central line between Morogoro and Tabora. Hence, they were given much bigger tenders than the Tribals 29s (Locobase 4330) from which they were also derived.

The last engine in the class -- Nyaturu -- was withdrawn in 1980.


Class 31 (Locobase 2494)

Data from Vulcan Foundry magazine ([] through 19, last accessed 7 July 2007); and "'31' class", East African Railways and Harbours Magazine, Volume 2, No 5 (October 1955), p. 14. Works numbers were 6228-6273 in 1955.

Husky freight engine based on the Nigerian "River" class for the metre gauge notable for the heavy platform over the leading truck, which had outside bearings, as well as a profusion of pipes and air pumps on the firebox lagging.

They were procured to replace older 4-8-0s in a variety of heavy shunting (yard switching) and branch-line operations. The design also lent itself to relatively easy conversion to the Cape gauge, which was only 3"(76.2 mm) wider. According to the Nairobi museum website [] (November 2002), these were similar to the Class 29 Tribals (Locobase , but had a smaller boiler and lighter tender.

NB: Tube length is an estimate based on the calculation of tube surface area by subtracting reported firebox heating surface from reported total evaporative heating surface

Principal Dimensions by Steve Llanso of Sweat House Media

Class3031
Locobase ID4329 2494
RailroadEast African RailwaysEast African Railways
CountryKenyaKenya
Whyte2-8-42-8-4
Number in Class2646
Road Numbers3001-30263101-3146
GaugeMetreMetre
Number Built2646
BuilderNorth BritishVulcan Foundry
Year19551955
Valve GearWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)13.25 / 4.0413.25 / 4.04
Engine Wheelbase (ft / m)30.92 / 9.4230.92
Ratio of driving wheelbase to overall engine wheelbase 0.43 0.43
Overall Wheelbase (engine & tender) (ft / m)63.67 / 19.4152.17 / 15.90
Axle Loading (Maximum Weight per Axle) (lbs / kg)25,200 / 11,43125,424 / 11,532
Weight on Drivers (lbs / kg)114,240 / 51,818100,800 / 45,722
Engine Weight (lbs / kg)165,760 / 75,188157,164 / 71,288
Tender Loaded Weight (lbs / kg)100,800 / 45,722
Total Engine and Tender Weight (lbs / kg)257,964 / 117,010
Tender Water Capacity (gals / ML)8400 / 31.825172 / 19.59
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)2340 / 8856.902000 / 7570
Minimum weight of rail (calculated) (lb/yd / kg/m)48 / 2442 / 21
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)48 / 121948 / 1219
Boiler Pressure (psi / kPa)200 / 13.80200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)18" x 26" / 457x66017" x 26" / 432x660
Tractive Effort (lbs / kg)29,835 / 13532.9426,612 / 12071.01
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.83 3.79
Heating Ability
Tubes (number - dia) (in / mm)121 - 2" / 51125 - 2" / 51
Flues (number - dia) (in / mm)28 - 5.5" / 14021 - 5.5" / 140
Flue/Tube length (ft / m)16.37 / 4.9916.10 / 4.91
Firebox Area (sq ft / m2)146 / 13.56124 / 11.52
Grate Area (sq ft / m2)38 / 3.5330 / 2.79
Evaporative Heating Surface (sq ft / m2)1844 / 171.311652 / 153.53
Superheating Surface (sq ft / m2)446 / 41.43328 / 30.48
Combined Heating Surface (sq ft / m2)2290 / 212.741980 / 184.01
Evaporative Heating Surface/Cylinder Volume240.81241.86
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation76006000
Same as above plus superheater percentage90447020
Same as above but substitute firebox area for grate area34,74829,016
Power L113,76512,237
Power MT1062.561070.55

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