Nigeria Railways Beyer-Garratt Locomotives in Nigeria


Class Details by Steve Llanso of Sweat House Media

Class 501 (Locobase 706)

Data from Gavin Hamilton's excellent compilation of Garratt data posted at [] (6 September 2005); and A[rthur] E[dward] Durrant, Garratt Locomotives of the World (revised edition) (Newton Abbott, UK: David & Charles, 1981), pp 108-109, 112. First batch BP #s were 6781-6784.

Four more Beyer-built batches followed over the next several years:

505-506 (6796-6797) in 1936

507-512 (6861-6866) (1937)

513-516 (6927-6930) (1939)

517-522 (7051-7056) (1943).

Double Pacific Garratts for the Cape gauge designed to be more suitable for the 45 lb/yard (22.5 kg/metre) track in the Highlands, but capable of running all the way to Lagos without change of locomotive. Durrant praised the NR's "Midland Red"engines as "particularly fine."

Clearly, the NR approved of the design as they ran most of the class into the 1970s.


Class 901/201 (Locobase 707)

Data from Gavin Hamilton's excellent compilation of Garratt data posted at [] (6 September 2005); A[rthur] E[dward] Durrant, Garratt Locomotives of the World (revised edition) (Newton Abbott, UK: David & Charles, 1981), p. 109-110, 112; nd "Nigeria Railway-Design 1159", Beyer-Garrrat Patent Articulated Locomotives (Manchester, England: Beyer-Peacock & Company Limited, 1931), archived on flickr's Historical Railway Images at [], et seq, p. 56. Works numbers were 6635-6636 in 1930.

Typical Double Mountain Garratts of the time using large Belpaire firebox. When they were introduced, the Chief Mechanical Engineer reported on their "excellent work". They hauled trains of 550 tons gross up 1.65% grades on the Minna-Kaduna section. "On the light and rough track, 45 lb/yard [22.5 kg/metre] badly worn," the CME added, "these engines ride like a coach."

Hamilton noted that this class, originally numbered 901-902, proved too powerful for Nigerian service. (Durrant added that the Garratts' trailing load limits overmatched the three-cylinder 4-8-2 locomotives running on the 80 lb/hard (40 kg/metre) track.)

The later, smaller Garratts arived in 1935 (Locobase 706); these possessed enough power

Principal Dimensions by Steve Llanso of Sweat House Media

Class501901/201
Locobase ID706 707
RailroadNigeria RailwaysNigeria Railways
CountryNigeriaNigeria
Whyte4-6-2+2-6-44-8-2+2-8-4
Number in Class222
Road Numbers501-522901-902/201-202
Gauge3'6"3'6"
Number Built222
BuilderBeyer, PeacockBeyer, Peacock
Year19351930
Valve GearWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)17.75 / 5.41
Engine Wheelbase (ft / m)53.75 / 16.38
Ratio of driving wheelbase to overall engine wheelbase 0.33
Overall Wheelbase (engine & tender) (ft / m)74.08 / 22.58
Axle Loading (Maximum Weight per Axle) (lbs / kg)21,840 / 990621,280 / 9652
Weight on Drivers (lbs / kg)130,816 / 59,337170,240 / 77,220
Engine Weight (lbs / kg)249,760 / 113,289281,792 / 127,819
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)249,760 / 113,289281,792 / 127,819
Tender Water Capacity (gals / ML)3888 / 14.734560 / 17.27
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 7.70 / 7 5.50 / 5
Minimum weight of rail (calculated) (lb/yd / kg/m)36 / 1835 / 17.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)48 / 121948 / 1219
Boiler Pressure (psi / kPa)200 / 13.80180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)13.5" x 26" / 343x660 (4)16.5" x 23" / 419x584 (4)
Tractive Effort (lbs / kg)33,564 / 15224.3939,919 / 18106.98
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.90 4.26
Heating Ability
Tubes (number - dia) (in / mm)
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)
Firebox Area (sq ft / m2)154 / 14.31163 / 15.14
Grate Area (sq ft / m2)31.40 / 2.9238.88 / 3.61
Evaporative Heating Surface (sq ft / m2)1517 / 140.991768 / 164.25
Superheating Surface (sq ft / m2)333 / 30.95368 / 34.19
Combined Heating Surface (sq ft / m2)1850 / 171.942136 / 198.44
Evaporative Heating Surface/Cylinder Volume176.09155.30
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation62806998
Same as above plus superheater percentage74108188
Same as above but substitute firebox area for grate area36,34434,328
Power L198147457
Power MT992.36772.55

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