The British Railways DVD The Early Years 1948-1961 is the definitive archive-film led history of the early years of Britain's nationalised rail network.
The formation of the British Transport Commission
A review of post-nationalisation motive power and the locomotive trials
An overview of the resulting BR Standard Class steam locomotives
The 1955 'Modernisation Plan'
The Western Region diesel-hydraulics
The relative merits of Steam and Diesel traction
Various suburban electrification schemes
Freight, marshalling yards, good depots, mail trains, cars by rail