Starting out in the 1970’s I had missed the steam era completely, and the diesels built for the British Rail Modernisation Plan in the 1960’s were the most common form of traction.
The Modernisation Plan was published in December 1954. It was intended to bring the railway system up to date. A government White Paper produced in 1956 stated that modernisation would help eliminate BR's financial deficit by 1962. The aim was to increase speed, reliability, safety and line capacity, through a series of measures which would make services more attractive to passengers and freight operators, thus recovering traffic that was being lost to the roads. The Modernisation Plan called for the rapid and large-scale introduction of diesel locomotives: a total of 2,500 locomotives to be procured in 10 years at a cost of £345 million.