I do a lot of research using Working timetables. Each of the regions did things differently. You need a contents page of a North Eastern Region Working Timetable from the period that you are interested in. Have you looked in Timetable World?
I am most familiar with Eastern Region working timetables, especially the Modernisation Plan era in East Anglia. In Eastern Region working timetables there was a period where the default was a loco hauled train, and "diesel" meant DMU. After steam finished, the default was usually DMU in rural East Anglia and EMU in the Liverpool Street suburban area, with H for loco hauled and also DU for diesel units in the suburban area. Some working timetables had different defaults for different tables within the same book.
There isn't much in Eastern Region working timetables about train formations, carriage working books are the source for that. The working timetables use a spade symbol to denote trains that were not allowed to convey 4 wheeled vans, and HC for loco hauled trains that were not allowed to convey additional non-passenger vehicles.
Given your area of interest have you looked at what is available from the North Eastern Railway Association?
We publish books on North Eastern Railway subjects, as well as a range of facsimiles of original documents. You may order by selecting from the titles in our on-line shop.
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