Named after the Napier Deltic diesel engines that powered them, the Class 55 Deltic locomotives served on Britain's railways from the early 1960s until the last examples were retired at the beginning of 1982. While in service, the Deltics dominated services on the East Coast Main Line between London King's Cross and Edinburgh and Aberdeen. Six are now in preservation. Obsessed by the Deltics since his childhood, Colin Alexander has photographed these charismatic locomotives in main-line service, in withdrawal and in preservation since the 1970s. Supported by the photographs of his long-time friend and fellow enthusiast Ian Beattie, his pictures make a wonderful and personal record of the Class 55 locomotives, the Deltics.