|NBL Type 1|
British Rail Class 16
No. D8403 in green livery with all-yellow front end at Stratford MPD in 1966
The North British Type 1 (later known as Class 16) was a type of diesel locomotive ordered under British Railways' 1955 Modernisation Plan. Like other Type 1 designs, they were relatively small locomotives intended primarily for local freight traffic. They were numbered D8400-D8409.
The design evolved from an earlier prototype locomotive built by North British, No. 10800. Under British Railways' 'pilot scheme', ten locomotives were ordered for evaluation against rival designs from British Thomson-Houston (Class 15) and English Electric (Class 20). The design shared some similarities with Class 15, both being of the road-switcher layout much like the design that was quickly becoming the standard in North America and Australia, and both being powered by an 800 hp (600 kW) Paxman 16YHXL prime mover.
The ten locomotives (numbered D8400–D8409) were completed at the North British Locomotive Company's Queen's Park Works in Glasgow, between May and September 1958. They were delivered to Devons Road depot, Bow, North-east London on the London Midland Region of British Railways for evaluation against the rival designs, but soon moved to nearby Stratford depot on the Eastern Region, where they stayed for the rest of their lives. The allocation of all ten locomotives in October 1967 was Stratford.
The design was not a success, and no further examples were built. While the Class 15s also suffered problems with the Paxman engines, these were worse on Class 16 because inadequate ventilation resulted in frequent engine seizures. Another problem was coolant contamination of the oil, due to cylinder head failure[clarification needed]. They were fitted with a non-standard type of electro-magnetic control equipment (coded "red circle" by BR) which was prone to failure, and they could not operate in multiple with locomotives fitted with the more common electro-pneumatic ("blue star") controls.
Being non-standard and unreliable, the locomotives were an obvious candidate for early withdrawal. They were withdrawn between February and September 1968, and all ten had been cut up for scrap by the end of 1969.
- British Rail Locoshed Book. Shepperton: Ian Allan. February 1968. p. 31. ISBN 0-7110-0004-2.CS1 maint: ref=harv (link)
- British Rail Locoshed Book. Shepperton: Ian Allan. February 1968. p. 32. ISBN 0-7110-0004-2.CS1 maint: ref=harv (link)
- Clough, David N. (2005). "Pilot Scheme Prototypes of Type A/Type 1". NBL D8400 series (later Class 16). Diesel Pioneers. Ian Allan. pp. 44–50. ISBN 978-0-7110-3067-1.
- Stevens-Stratten, S.W.; Carter, R.S. (1978). British Rail Main-Line Diesels. Shepperton: Ian Allan Ltd. ISBN 0-7110-0617-2.
- Sugden, S.A. Diesel & Electric Loco Register (3rd edn). Sheffield: Platform 5. ISBN 1-872524-55-9.
- Grindlay, Jim. British Railways Locomotive Allocations 1948-1968 (Part 6 - Diesel & Electric Locomotives). Troon: Modelmaster Publications. ISBN 978-0-9544264-6-0.
- McManus, Michael. Ultimate Allocations, British Railways Locomotives 1948 - 1968. Wirral. Michael McManus.