In The Deltics and Baby Deltics Andrew Fowler takes a comprehensive look at the Class 55 locomotives, better known as the Deltics. After examining the forerunners to the Deltics, which were impeded by their weight, he describes how English Electric developed an engine, originally designed for aircraft, then adapted for submarines, which was considerably lighter. The new, 18-cylinder engine was triangular in shape, similar to the Greek letter Delta and this gave rise to its ‘Deltic’ name. He explores in detail how problems in the development of the prototype Deltic were overcome. Construction of the prototype commenced in 1954 and by late 1955 testing was in progress, but it was not until 1956 that the train was ready to begin running under assessment in passenger service duties. English Electric continued running the prototype in traffic until November 1960 when it was withdrawn requiring work; this was not authorised and an offer to donate it to the Science Museum in London was made in 1962, the official hand-over ceremony taking place in May 1963.
Whilst the prototype was never accepted into British Railways service, in 1959 the Eastern Region placed an order for 22 of the Deltic locomotives, along with 13 spare engines. In the production series the power units were an improved version of the prototype unit and when first built each locomotive weighed 99 tons. The allocation of the locomotives was split, with 8 going to Finsbury Park in London, 8 to Haymarket and 6 to Gateshead; in 1962 they were all named – the 8 at Finsbury Park after famous racehorses and the other 14 called after regiments. The author gives further details for each of the 22 locomotives in turn.
Also covered are the Baby Deltics which were produced to handle branch line traffic, at a maximum axle load of 18 tons. To help them achieve this weight they were manufactured using a 9-cylinder engine, but once built they were over the tonnage and several components had to be refitted with lighter parts. The 9-cylinder engine used, compared to the 18-cylinder currently in use on the prototype, earned it the Baby Deltic name. Only 10 Baby Deltics were produced and all were to be withdrawn within a decade, due to their lack of success in main line service. Andrew Fowler also looks at an ongoing project to produce a new Baby Deltic locomotive. Over 140 colour and black & white photographs. Hardback. 200 pages.