Not LNER, of course, but I'm hoping somebody with more knowledge than me can help me answer this question.
The September 1961 to June 1962 WTT shows three type of local passenger services:
DMU operations
Unspecified operations, which would normally indicate steam-hauled services
Trains marked "AT" (accelerated timings)
It is the latter I'm intrigued by. There is evidence to suggest these are diesel-hauled passenger stock - for instance I have found photographic evidence that the D57xx Co-Bos used to bang, thud and clatter their way between Derby and Manchester on stopping services at this time. Derby had a large allocation of these at this date but I don't know what else they used to do, maybe they were all on shed under repair ...
In most cases I have found, "AT" services seem to be on lines with cruel gradients and long tunnels which would certainly be a point in favour for conversion to diesel operation.
Almost all services on the Hope Valley line are also shown as "AT" at this date (but not on Sundays it seems) and I'm wondering what locos would have operated these services. It looks like all but one were served from the Sheffield end (one seems to outstable at Chinley overnight) so the best offering I can come up with is English Electric Type 1s or Brush Type 2s from Darnall shed. Can anybody confirm or disprove this?
