John Law 
Railways of the Eastern Counties Since 1970 [EPUB ebook] 

Over more than fifty years, the railways of the Eastern Counties have seen a great number of changes. In the early 1970s, many stations, even some of the smaller ones, had a resident diesel shunter for moving empty carriages or servicing the goods yard. First generation diesel multiple units ran most of the secondary lines, with locomotive-hauled expresses being used on the Inter City routes and the Harwich boat trains. Today, modern electric trains speed northwards to Norwich and Kings Lynn, while comfortable diesel units serve the cross-country routes. New electric or bi-mode sets are now operating on other lines. Semaphore signalling has mostly given way to centralised colour light systems.