British Railway Atlas 1955: Dawn of the Modernisation EraBritish Railway Atlas 1955: Dawn of the Modernisation Era 20. 00 The mid 1950s marked a high point in the history of Britain's railways. Seven years after the nationalisation of the 'Big Four' railway companies in 1948, there was a feeling of optimism within the industry. The 'Modernisation Plan', with its promise of wholesale dieselisation and main line electrification, was intended to bring a new era of profitability, and it was still possible to