Caledonia (colloquially known as Cale, and in case of any doubt - pronounced Cal-ee) is unique on the island in every respect; a one-off order from Dübs & Co., in 1885 and is the only engine on the line to have been provided by the Glasgow manufacturers to the island; designed to cope with the steep gradients of the Foxdale branch to which it was ideally suited, the branch was not the success it was hoped to be and the locomotive saw little use after the merger with the Isle of Man Railway in 1905, but remarkably was chartered to assist in construction of the Snaefell Mountain Railway in early 1995.  It was later numbered No.15 in the fleet and saw use rarely in service, largely relegated to mart specials and snow clearing duties.  It was re-boilered in 1922, and was the first to carry Ross “pop” safety valves (replacing the original Ramsbottom valves).  It is this boiler that remains today.  Stored when out of use in the open courtyard to the rear of the running shed at Douglas Station (site of the infill shed today), her last duties were on snow clearances in 1964/1965 fitted with a small plough.

In 1967 the locomotive was chosen to break through the ceremonial ribbon on reopening day at Douglas Station and it was repainted into the Spring Green livery, later seeing use on the south line, though poor steaming and inexperienced crews meant that it was not favoured in regular service; indeed is was only pressed into traffic when no other locomotives were available.  In the spring of 1968 it was repainted again into an approximation of the original Manx Northern Railway scheme to haul a special train to St. John’s for the fledgling Supporters’ Association, hauling Royal Saloon F.36 and Governors’ Saloon F.75 (among others) for the occasion.  This would prove to her her final sojourn in service and shortly afterwards it joined the display locomotives at St. John’s and later Douglas Station the following year.  By 1975 it had entered the railway museum at Port Erin Station at the head of the Manx Northern Railway train and it would stay displayed here until September 1993 when it was returned to Douglas by road for feasibility studies for a return to service.  

These were a success and the locomotive took centre stage for the centenary celebrations of the Snaefell Mountain Railway in 1995, returning to the slopes of the island's only mountain. Returned to an accurate 1885 livery based on work carried out during reassembly and the official works photograph, the locomotive also operated on the Manx Electric Railway that year between Laxey Station and Dhoon Quarry.  It remained in regular use and was repainted into an appropriate Caledonian Blue livery in 1999 in which it operated until 2007.  A further major overhaul followed in 2009 which also saw a repaint into the original scheme.  More works were carried out which saw a return to service in 2013 but the following year it was withdrawn with boiler issues.  More overhaul work followed so that by April 2018 the locomotive was on test, returning to regular use in September 2018 after the most extensive strip-down since it had left the factory.  Today it is often seen in service alongside the familiar Beyer Peacock locomotives and is popular with the travelling public.