Some locomotive subclass queries

[Western 52]

Thank you everyone for your replies to this topic. It's proving to be a more interesting and involved thread than I imagined!

 

[Helvellyn]

The DMUs were not renumbered until 1983, by which time the single cars had the 55xxx series to themselves. Given there were only 50 class 50s and 135 class 56s, renumbering nearly 2000 DMU cars seemed a bit of an over-reaction. In 1983 there was still plenty of headroom beyond the 50000-52105 and 56000-56504 blocks to renumber only the vehicles that duplicated locomotives. (e.g 52151/52200 and 56601-56735), and it would have left the entire 53000-54999 block free for new DMUs

Two DMU trailers 59101 and 59105 were renumbered (to 59110 and 59111) in 1990, and a few surviving SR DEMU cars 60014/15/16/18/100/101 (to 60152/53/16/18/54/55) around the same time.

There were only 22 Class 81s, yet the entire 81xxx range of NPCCS (81000-81628) were renumbered into the 84xxx series!

 

[norbitonflyer]

There were only 22 Class 81s, yet the entire 81xxx range of NPCCS (81000-81628) were renumbered into the 84xxx series!

Indeed, I'd forgotten about hauled stock.
14xxx renumbered 17xxx to avoid clashing with former Southern EMU railway stock (actually built by BR on older SR underframes, but numbered in the SR series).

vehicles between 15000 and 15999 were renumbered in the 7xxx series for the same reason, although the highest numbered 15xxx EMU vehicle was S15481S and the lowest numbered surviving Mark 1 was 15626.
vehicles between 16000 and 16258 were also renumbered in the 7xxx series. The highest numbered 16xxx EMU vehicle was S16134S.

25005 to 26217 were renumbered in the 18xxx and 19xxx series, although less than a quarter of the renumbered coaches duplicated locomotive numbers

86xxx renumbered 93xxx (nearly 1000 vans, although there were only 100 class 86sthe various subclasses were scattered throughout that range)
855xx renumbered 940xx although there was never a subclass 85/5

 

[marsker]

The ten (D5102-D5111) were allocated to Gateshead from new, and worked from there until around 1966 with train heat boilers. They then moved to Tyne Dock to replace the 9Fs, after modifications at Crewe/Derby Works.

The compressors weren't actually for air brakes, the ore trains were vacuum braked. The compressors were required to operate the wagon doors, the trains pulled onto the unloading gantry at Consett and the doous were opened by the loco crew. Once unloaded, they shut the doors, reversed the train round a triangle and set off back. Sort of the precursor of the later merry-go-round coal trains, but much less automated.