No.12 Hutchinson was a one-off order from 1908 from Beyer, Peacock & Co., and was similar in design to the 1905 locomotives No.10 G.H.Wood and No.11 Maitland.  As was common at the time, the locomotive was named after company director William A. Hutchinson following the previous two locomotives.  Delivered with Salter safety valves as standard and a deeper tone of whistle than had previously been used the locomotive remained a regular performer for many years, re-boilered shortly after the war in 1946, a move that would see her in regular service until the government takeover in 1978.  She was one of the locomotives in the fleet when Lord Ailsa took over the operation of the railway in 1967 and was repainted into the Spring Green livery at this time in common with other locomotives.  By 1977 the condition of her boiler was poor and she saw limited use, the decision being taken to order a new one.

No.12's new boiler was delivered from the Hunslet Engine Co., of Leeds and arrived in early 1981 at which time reassembly began.  Memorably, this was to include larger water tanks and a square cab modelled loosely on that carried by No. 16 Mannin.  It was these cumbersome new additions, together with a blue livery gave her an ungainly appearance.  Due to the taller tanks, the locomotive was susceptible to rolling when at speed and the livery was not popular with purists (indeed in this world of social media any images that emerge of her in this guise inevitably lead to comments of “....liked her when she was like that...”  which seems to verge on a form of tourette's syndrome).  Returned to service in 2001 with a replica traditional cab and in the post-war Indian Red livery, this was later added to be the re-addition of the brass fleet numbers above the nameplates - lost prior to the 1981 rebuild and was reinstated in 2009 at the same time as the chimney numerals were removed, looking rather odd on the smaller cast chimney.  A further spell out of use for work saw her return to traffic in April 2017 but following expiration of boiler certificate in August 2019 she was withdrawn for majot work with an overhaul commencing in May 2021 which is ongoing at the present time.  It is likely that the locomotive will return to service in time for the 2024 season.