A couple of items from the past.
Up to the 1960s some Scotland to Blackpool trains ran through Preston, travelled via various junctions south of there and re-appeared at Preston (probably to the consternation of some passengers) now facing the right way for Blackpool.
In the '80s I caught the overnight Sheffield - St Pancras quite frequently. It was booked to stop at both Derby and Nottingham and on a couple of occasions the direct Sheffield - Derby line was closed so the route became:
Chesterfield - Toton - Trent East Jct - Derby (rev) - Trent East Jct - Nottingham (rev)- Trent East Jct - Loughborough.