English Electric Class 55 : Deltic Diesel Electric Locomotives, Flagship of the East Coast Main Line

The East Coast Main Line has achieved a well-deserved reputation as the showground for some of the fastest trains to run between London and Edinburgh. Often remembered as ‘the route of the Flying Scotsman’, in steam days it was the iconic Gresley A4s which raced between the two capitals. As steam traction came to an end the search was on for a worthy replacement. Locomotives which could haul heavy passenger trains at even faster speeds along a track designed for record breakers. The age of the diesel-electric locomotive was upon us. Many were tried and tested before one would come to the fore. The engine design of ‘the chosen one’ was revolutionary in itself. Never before had such a concept been applied to railway locomotive power units.The long-established London engineering company of D. Napier and Son had built a reputation for power and precision, from motor cars to engines for the armed services and as time passed their designs evolved into high-speed compression-ignition forms generating exceptionally high power and thermal efficiency with very low fuel consumption. From these the inverted Delta design with its triangular opposed piston layout was developed. The Deltic engine was born and to house it the locomotive which would carry its name. A class of locomotive which would go on to set new standards when they emerged from English Electric’s Vulcan Foundry to grace the East Coast Main Line.