Nigerian State 4-6-0 Locomotives in Nigeria

Class 401 (Locobase 20161)

Data from "Express Engine, Nigerian Railways", Locomotive Magazine, Volume XVIII [18] (15 December 1912), pp. 203-204; and "4-6-0 Locomotive: Nigerian Railways", Locomotive Magazine, Volume XXVI [26] (15 November 192)0, pp. 238-239. See also James T Hodgson and John Williams, Locomotive Management from Cleaning to Driving, Fourth Ed, Revised (London: The Proprietors of "The Railway Engineer", 1920), p. 26; and "New Locomotives for the Nigerian Railway", Railway Engineer, Volume 41, No 10 (October 1920), p. 425 . (Thanks to Teemu Koivumaki for his 19 August 2024 email supplying key information for several Nigerian Railways classes.) Works numbers were 1005-1008 in 1913.

A year after Nasmyth Wilson delivered its 4-8-0s (Locobase 9568) to the NSR, it followed with this quartet of express passenger Ten-wheelers. LM reported that they would handle the once-a-week boat train that linked Lagos once a week, with sleeping accommodations and a restaurant car, on a 650-mile (1,047 km) run to the junction for the Bauchi Tin Mines at Zaria.

LM mentions the inclusion of a "Galloway-Hill patent furnace" in the design's Belpaire firebox. Hodgson explained that a typical Galloway-Hill installation featured four or more separate grate sections laid transversely (across the firebox, i.e.). They lay on four air conduits running longitudinally that had trumpet-shaped openings at the footplate end into which an injector would spray steam.

Hodgson stated that "the action of this steam jet is similar to that of an injector, thus giving an increased supply of air at a pressure above that of the atmosphere below the grate." Creating a "forced or positive circulation of air.", the atomised steam increased combustion efficiency. Each conduit had its own air supply, which prevent holes in the coal bed through which cold air would enter. He noted that this method had proved especially useful for burning "cheaper grades of coal with which a fireman is often expected to generate the necessary steam."

Tender capacity measured 202 cubic feet (5.72 cu m).