For the opening of the railway between Ramsey and St. John’s on 23rd September 1879 the Manx Northern Railway Co. Ltd., made enquiries with a number of manufacturers including The Metropolitan Carriage, Wagon & Finance Co., Brown Marshall & Co., The Ashbury Carriage & Wagon Co., and The Bristol Wagon & Carriage Works Co. And finally settled with The Swansea Carriage & Wagon Co., for a set of fourteen six-wheeled carriages with which to commence their passenger operations.  This was at odds with the existing Isle of Man Railway Company who began operations in 1873 using exclusively four-wheeled rolling stock until the introduction of their first bogie vehicles which would not be until 1881.  The first two were of First Class accommodation, with the remaining twelve  Second Class including two with brakes and eight without; as the fledgling company did not have sufficient capital, ownership was initially retained by the builders and vehicles carried iron plates denoting  the Welsh company as their owner.  The yearly rent was set at £123 4s. 2d., £482. 17s. 0d. and £112 2s. 2d. respectively for the various classes.  

The principal involved three separate wheelsets, a set at either end with their own axles and trucks, the central set being mounted on slides to give radial play on curves, thereby protruding from beneath the body on such alignments.  The two outer wheelsets were connected to the central one by pivoted radial links; this arrangement was less expensive than the more common bogie arrangement and also meant the same lateral strength of the frames was not required, as was the case on the bogie stock on the I.M.R.  The carriages were 30’ 0” long with axle centres 12’ 0” apart, constructed on oak frames with the solebars featuring ¼” facing plates and tie rods located centrally along the length of the frames; the bodywork was economically produced in teak, featuring square-cornered windows apart from the first class carriages, the upper corners of the window on these had curved corners; a lower running board was carried the length of each carriage, while the upper steps were individual beneath each compartment door.  It is recorded that when delivered the finish of the teak bodywork was found to be lacking with further varnish required, and the coupling arrangement was unsatisfactory, being modified almost immediately upon delivery.

When the Manx Northern Railway Company was bought out by its competitor in 1905, they were renumbered F.40-F.51 continuing the series at that date; however in 1907 further bogie stock was purchased and fleet numbers amended to N.40-N.51, this being the next available lettering prefix.  They were not favoured for regular use after this period, commonly being pressed into service on busy days such as Tynwald Day each July, but regular usage was uncommon; it is speculated that they were never used on the South Line and no photographic evident exists to support this.  By the 1930s they were all but withdrawn and relegated to storage in the carriage shed at Ramsey Station.  The last recorded use in traffic by any of them was on 5th July 1950.  Following the lease of the carriage shed they were relocated to open storage on a spur to the side of St. John’s carriage shed known colloquially as Harry Cubbon’s Wing, which is where they remained until the closure of the railway.  Six of them were badly damaged in the shed fire on 10th December 1975 and later destroyed by controlled fire the following year.  Prior to this four examples were saved, two entering the collection of Peter Rampton and being removed from the island in 1975, with a further two sold locally.