Nigerian State 4-8-0 Locomotives in Nigeria

Class 257 (Locobase 20055)

Data from Locomotive Magazine, Volume 18 (15 October 1912), pp. 203-204; and "Eight-Coupled Bogie Locomotive: Nigerian Railways", Locomotive Magazine, Volume XXVII [27] (15 July 1921), pp. 167-168. See also D[ennis] Rock Carling, 4-8-0 Tender Engines (New York: Drake Publishers, Inc, 1972), pp. 63 and serial 168, Table X [10] B, pp. 104-105. Nasmyth Wilson works numbers were 966-968 in 1912 and 1024-1025 in 1914; North British Locomotive Company produced road numbers 268-281 in 1915. After the end of World War ! William Beardmore & Co, Ltd supplied nineteen in 1920.

This large class of twelve-wheelers used large Belpaire fireboxes and grates to motivate the water in the first new engines to be delivered to the newly amalgamated Nigerian State Railway. The relatively large cylinder volume for so small an engine doubtless benefited from superheating the steam, although the superheat ratio was on the small side. Six axles allowed the freight engines to run on the 45 lb/yard (22.5 kg/m) rails north of Jebba.

LM's report explained that the port of Lagos was the meeting point for the Northern Nigerian, which ran north 467 miles (752 km) to the Baro-Kano line at Minna, and the Southern Nigerian, which linked Lagos to the Niger River town of Jebba some 306 miles (493 km) distant. The rails weighed 50-55 lb/yard (25-27.5 kg/metre) and the ruling grade was no more than 1 in 80 (1.67%) on the main line and 1 in 50 (2%) on the branches.

After more than twenty years of service, the three Nasmyth Wilson engines were overhauled by the NGR shops in 1933. The prinicipal specifications shown in Locobase did not change.

Class 301 (Locobase 20843)

Data from D[ennis] Rock Carling, 4-8-0 Tender Engines (New York: Drake Publishers, Inc, 1972), pp. 63 and serial 171, Table X [10] B, pp. 104-105 .North British produced four in 1914, 12 in 1915. After World War I, the NGR procured 16 from newly formed Armstrong Whitworth locomotive works. (A-W already was a premier shipbuilder and steel producer.)

A year after introducing the large class of small, superheated 4-8-0s, the Nigerian Railways began buying a larger design that had more power, taller drivers, larger boiler, firebox, and grate, and more adhesive weight.

(Carling wrote that the superheater area--314 sq ft (29.17 sq m)--was measured from the "water side". Locobase observes that superheater area isn't dependent on flue diameter measurement. In the table, he noted that another figure given is 228 sq ft (21.18 sq m). That is the number used in the Locobase specs. The 314 sq ft figure may represent flue area with tube area contributing 1,010 sq ft (93.83 sq m).)

Sixteen of the class were rebuilt by NGR shops in later years. Eight were turned into 4-8-2 with "much larger boilers", wrote Carling. Another eight were reworked between 1935 and 1942, receiving 19"(483 mm) diameter cylinders, more firebox heating surface area (140 sq ft/13.00 sq m) and grate area (29.4 sq ft/2.73 sq m), and boilers pressed to 180 psi (12.4 bar).

Carling observed that the rebuilds "could haul 50 to 100 tons more, steamed better, and used less fuel and water." (Win-win-win ...). The class lasted throughout World War II before being retired in 1946.

Class 606 (Locobase 20845)

Data from D[ennis] Rock Carling, 4-8-0 Tender Engines (New York: Drake Publishers, Inc, 1972), pp. 65 and serial 176, Table X [10] B, pp. 104-105 .Nasmyth Wilson built three in 1924 (works numbers 1420-1422 in 1924), North British Locomotive Company delivered 19 in three batches beginning in 1925 (Works numbers were 23305-23308 in 1924, 23344-23355, 23393-95 in 1926). And Robert Stephenson & Co completed the class with six 1928 (works numbers 3974-3979 in 1928.

Carling claimed that this set represented a design little changed from the original 1912 classes shown in Locobase 20055. Yet the boiler contained a superheater and "improved design and construction of boilers, cylinders and valve gear". Performance by these later engines, wrote Carling, "had much improved."

Class Modified Cape - superheated (Locobase 20842)

Data from D[ennis] Rock Carling, 4-8-0 Tender Engines (New York: Drake Publishers, Inc, 1972), pp. 63 and serial 167, Table X [10] B, pp.104-105.

In 1908-1911, twelve Modified Cape class went to work on two Nigerian railways (Locobase 20841). More than twenty years later, Nigerian Railways shops retired ten of the class, but fitted superheated boilers to the other two. Unlike many such conversions, the NGR recast the design by increasing cylinder volume and slightly reducing boiler pressure, increasing driver diameter by 5 1/4" (133 mm), and enlarging the tenders. The power dimension tradeoffs were well judged; starting tractive effort increased by only 28 lb (12.7 kg) . Weight increased by a similarly small amount.

Revamping the design conferred another seventeen years of service on the pair before they retired in 1951.