These vans were built for carrying cattle and were similar in appearance to the "G" vans, but had the top ¼ as open barred space.  They had vertical planking with air gaps between and central opening doors.  The enterprising I.M.R. utilised many other component parts as recorded below, notably the frames from the disused four-wheel "A"-"D" class coaches.  Certain vehicles were roofed; where scrapped date is not provided this is purely because it is not known, there are no representatives of this class in existence today.

In addition to the above, it is of note that K.10 - K. 12 were the first I.M.R. built wagons, with K. 10 being rebuilt as unroofed using components of M.45.  The other two similarly (but roofed) from M. 43 and M.44 respectively.  K.11 & K.12 were roofed by the I.M.R. in 1916, whilst K. 13 & K. 14 were converted to sheep trucks in 1924 and became K.13a & K.14a, the only members of this sub-class.  K.15 was given a “G” van body in 1919 and K.16 - K.19 were given “G” van bodies, in the 1920s (with K.17 and K.18 being distinguishable as they did't have portholes); all three were scrapped at an unknown date.  The “new” K wagons were built in-house to replace reclassified vans.  For instance, the original K.15 was converted to a “G” van so a new one built to replace it.  The replacements for K.1, K.2 and K.5 were simply to replace scrapped stock as above.  By the dates given above there must have been two K.13s for a number of years!