A detailed history of Class 15 and 16 “Pilot Scheme” diesel locomotive classes, ordered by British Railways following the 1955 “Modernisation Plan”. Both designs, from British Thomson-Houston (BTH) and North British, fell into the lower-powered Type 1 classification devised by BR; initial orders were placed for 10 examples of each, these being introduced between 1957 and 1959 for use in East London, and on the Great Eastern and London, Tilbury & Southend lines.
The availability of spare manufacturing capacity led BR to order a further 34 examples of the BTH Class 15 design, before substantial type testing had taken place. Unfortunately, both designs proved to be inferior to the highly reliable English Electric Class 20, hence construction ceased after the 54 examples had been delivered.
The North British fleet survived until 1968, being withdrawn after ten years of indifferent performance. The BTH locomotives followed by 1971, although four found a new role as carriage pre-heating units. Dramatic reductions in goods traffic during the 1960s and 1970s particularly impacted local trip and transfer freight duties, the very work for which Type 1 locomotives were designed, thus it was inevitable that the less successful classes were retired from traffic first.
The BTH & North British Type 1 Bo-Bo Diesel Electric Locomotives examines the classes in detail, including a look at the initial reasons for their construction and an evaluation of the technical merits of each class. The designs, acceptance testing, performance and maintenance are all covered.
The book also includes a detailed history of every locomotive in each class, with date to service, allocation histories, works overhauls, withdrawal, storage and disposal information provided. Every locomotive in each class is illustrated, most in black & white but with some colour material.
Liveries and detail differences are explained and further chapters look at the use of BTH locomotives in departmental service and the single loco that survives in preservation. 352 pages. Hardback.