North Eastern 4-4-4 Locomotives in Great_Britain

Class D/H1 (Locobase 3654)

Data from "4-4-4 Passenger Tank Engine, North Eastern Railway", Locomotive, Volume XIX [19] , Volume 256 (15 December 1913). 20 went into service in 1913-1914 and another 25 were built in 1920-1922.

Vincent Raven's intent in producing cross-country passenger tank engines in this wheel arrangement was to permit smooth running in each direction. Although the resulting design put a relatively low percentage of weight on the drivers, the factor of adhesion suggests it was sufficient. The boiler seems awfully small for the grate although the superheater ratio was relatively high for a British locomotive of the time and the high stroke-to-bore ratio combined with a typical cutoff could have extracted more power than usual from each incoming packet of steam supplied by the three 7 1/2" (191 mm) piston valves.

Locomotive's report said that they were designed for "heavy local passenger traffic in the Darlington, Saltburn, and Tebay districts", thus supplanting the 901 class four-coupleds.

They were later rebuilt as Class A8 4-6-2 tender engines; see Locobase 5911.

See Ahrons (1927). Richard Marsden's LNER Encyclopedia [] (viewed 1 February 2005) gives a smaller superheater area (194.134 sq ft).