The Sligo, Leitrim and Northern Counties Railway operated a 43-mile line in northern Ireland from 1877, which consisted only of the main line and had no branch lines. However, since this route, which was built in the Irish broad gauge of 5 ft 3 in, was only laid out with light rails, the running characteristics of the two 0-6-2T locomotives “Pioneer” and “Sligo” left a lot to be desired. The solution was to replace the trailng axle with a bogie. 

The company Beyer, Peacock & Co. had delivered locomotives of this type to the South Australian Railways as class K from 1879, which were also designed for lightly built routes. So they ordered two locomotives with the names “Fermanagh” and “Leitrim”, which were basically an enlarged class K. Since these proved themselves, three more examples followed by 1899, named “Lurganboy”, “Lissadell” and “Hazelwood”. The first of these locomotives, now known as the Leitrim class, were not retired until 1947 and one remained in service until 1957, when the SL&NCR ceased operations.