The resulting superheated locomotives had an increased tractive effort of and weighed . Other superheated locomotives also arose from conversions. There were eventually 44 conversions, 26 were of the Aspinall engines (which gained a Belpaire firebox at the same time), 18 of Hughes' own version with Belpaire firebox. When Hughes introduced his classification system around 1919 the more powerful superheated locomotives were designated "Class6", non superheated locomotives being Class5. The locomotives passed to the London, Midland and Scottish Railway (LMS) in 1923. LMS numbers were 10900–10954, except for 9 which were converted after the grouping without being renumbered. Horwich Lot 1 comprised 10 locomotives; the rest 20 each. The set of short-bunkered frames were used to create an LY&R electric locomotive in 1912. Bullid claims the radial tanks made at excellent start to service life with No. 1008 going from the works and into service with no teething troubles in February 1889. By the summer of 1891 they had gained a reputation for handling some of the more difficult L&YR routes including the adverse gradient of the Oldham Branch with at 1in52 then a further half mile at 1in44. Their duties also included the steepest passenger line in England, 127 for the Werneth spur. In 1903 the incumbent CME Henry Hoy reported that the now 270 strong class had between them covered in the preceding 14 years all over the L&YR system. They had suitable ability on passenger duties to haul a considerable load at any reasonable speed. The last batch of 2-4-2 radial tanks entered service in 1911 and these more moreful superheated LY&R Class 6 were allocated to run some express passenger services to some extent as the unrebuilt Hughes 4-6-0 had multiple problems and the Aspinall Atlantics were beginning to exhibit high levels of unserviceability. However the L&YR were severely censured by the Boarad of Trade in the 1912 Charlestown curve derailment inquiry report for use of large radial tanks on high speed passenger services but despite protestations reputational damage seems to have resulted and the practice somewhat discontinued. On 1 January 1922 the LY&R amalgamated into the London North Western Railway (LWNR) and the fleet passed on into the London, Midland and Scottish Railway (LMS) with the initial grouping on 1 January 1923.