Missing Diesel Classes ?

[Bright Boy]

Well we worked out the class 34.. Now 33/1

Would the 75 have been given to "Tommy" the original EM1? Just a thought.. I don't know how copyright lasts, but have an article from 1974 about TOPS at Inverness..

I'm still not sure about the 33/1's, but it is looking likely, do you know what is the source of that article ?

I also have heard that Class 75 was for Tommy (can't remember where ?), but Helvellyn has suggested that it was reserved for a 'Super Electro-Diesel' but I have not seen anything anywhere to back this up ?

 

[Helvellyn]

Seeing as the loco/unit TOPS is built around this class structure with originally clear definitions of what each bit means, you'd think randomly numbering coaching stock into the same ranges was a massive oversight.

But the coaching stock number system was set up in the 1950s, and the TOPS classification for locomotives only really came into play in the 1970s. I think by the 1980s BR needed to avoid same number clashes, hence why the coaching stock renumbering took place.

Also, as someone else mentions, Driving Trailer DMU vehicles (56xxx) were renumbered in the 54xxx series to avoid a clash with Class 56 locomotives. Just as 50xxx Driving Motor DMU vehicles were renumbered in the 53xxx series to avoid a clash with Class 50 locomotives.