Andrew Fowler is a well known writer of railway history, with a regular feature in Railway Herald Magazine. The Deltic class 55 Locomotives were some of the most successful, first generation diesels introduced to British Railways, being constructed from [tel] and numbering twenty two, in the production class. The prototype machine was constructed in 1956 and was tested extensively on express trains on the London Midland and Eastern Regions of B R, until 1960. The interest and enthusiasm, for the class is reflected in the fact, that six examples of the class are preserved, including the 1956 prototype. The Baby Deltics, were a derivative Locomotive design, using one rather then two engines, for use on outer suburban and short main line semi fast services. Only ten Baby Deltics were constructed between [tel], for use on services out of London Kings Cross. The Baby Deltics were all withdrawn within a decade, as they were not very successful in main line service.