Until quite recently the Boston Lodge works had several cats. (I do not know if there is one resident at present) However, at the time I am thinking of, some years ago now, it was not uncommon to find one asleep on one footplate or another! - basically anywhere warm! The other place was in the sawdust/shavings in the carriage 'shop. In fact, one member of staff was heard to remark that 'we don't build carriages, this place is a cat litter production facility'!! And once, in the early 1980s, I took a cat to Bleanau and back (the cheeky object had slept under the seat in the first class!)
The other place to find cats was near to the volunteer hostels - some railway volunteers can be suckers for the 'silent miaow', and virtually lived in! Although one black and white jellical did have a proper home just up the road he could often be found waiting for a cuddle! when I got back.