British Rail Class 15

BTH Type 1 British Rail Class 15
Sole surviving Class 15 no D8233 seen at Baron Street Loco Shed, East Lancashire Railway, February 2006
Type and origin Power type Diesel-electric Builder British Thomson-Houston at Yorkshire Engine Company (Initial Batch) British Thomson-Houston at Clayton Equipment Company (Second Batch) Build date 1957–1961 Total produced 44
Specifications Configuration: ​  • UIC Bo'Bo'  • Commonwealth Bo-Bo Gauge 4 ft 8+1⁄2 in (1,435 mm) standard gauge Wheel diameter 3 ft 3+1⁄2 in (1.003 m) Minimum curve 3.5 chains (70.41 m) Wheelbase 31 ft 0 in (9.45 m) Length 42 ft 0 in (12.80 m) Width 9 ft 2 in (2.794 m) Height 12 ft 6 in (3.810 m) Loco weight 69 long tons (70 t; 77 short tons) Fuel capacity 400 imp gal (1,800 L; 480 US gal) Prime mover Paxman 16YHXL Displacement 78.4 L (4,780 cu in) Generator Main : BTH RTB10858 Auxiliary : BTH RTB7420 Traction motors 4 x BTH 137BZ, nose suspended, with single reduction gear Cylinders 16 Cylinder size bore: 7 in (178 mm) stroke: 7+3⁄4 in (197 mm) Transmission Diesel electric MU working ★ Blue Star Train brakes Vacuum
Performance figures Maximum speed 60 mph (97 km/h) Power output Engine: 800 hp (597 kW) At rail: 627 hp (468 kW) Tractive effort Maximum: 37,500 lbf (167 kN) Brakeforce 31 long tons-force (310 kN)
Career Operators British Railways Numbers D8200–D8243 Axle load class RA 4 Retired 1968–1971 Disposition 1 preserved, remainder scrapped

The British Rail Class 15 road-switcher diesel locomotives, also known as the BTH Type 1, were designed by British Thomson-Houston, and built by the Yorkshire Engine Company and the Clayton Equipment Company, between 1957 and 1961. They were numbered D8200-D8243.

Design history

Following the British Railways Modernisation Plan, ten of the class were ordered for evaluation under the 'pilot scheme'. Like other locomotives designed to the 'Type 1' specification, they were intended for use on local freight and empty coaching stock trains.

Construction

The design and manufacture was a collaboration between several companies. BTH (the main contractor) provided electrical equipment, Paxman supplied the power units, and Clayton supplied bogies and superstructure, with the frame construction and final assembly taking place at Yorkshire Engine's Sheffield works. These ten locomotives, numbered D8200–D8209, entered service between November 1957 and November 1958.

The design showed sufficient promise for a repeat order for 34 more locomotives to be placed soon afterwards. These locomotives, numbered D8210–D8243 and built by Clayton at Hatton, Derbyshire, were delivered between October 1959 and February 1961.

Working life

The first ten locomotives were delivered to the London Midland Region's Devons Road depot in Bow, East London, where they were evaluated against the contemporary North British Type 1 and English Electric Type 1 designs. Soon, however, the entire class was allocated to depots on the Eastern Region, where they remained until withdrawal. The second block of ten was originally allocated to March depot in East Anglia, however due to the Clean Air Act 1956 the locomotives were quickly re-allocated to East London, allowing the replacement of steam locomotives in that area. Thereafter, the type was allocated exclusively to Stratford, Finsbury Park and Ipswich depots.

Accidents and incidents

On 21 November 1963, locomotive No. D8221 crashed through buffers whilst shunting at Ipswich, Suffolk and ended up across Croft Street. After attempts to tow it back onto the track using diesel locomotives failed, it was retrieved using the only steam locomotive in service at Ipswich, which had been retained for carriage heating purposes.

Problems

The class were troubled by several reliability problems, notably with the engines which were found to require excessive maintenance. A series of modifications to the pistons, piston rings and maintenance schedules, and fitting cast iron cylinder heads improved the engine reliability considerably, but a complex V16 for only 800 bhp and a small class size doomed them with a contracting rail network. The layout, with a single cab positioned part-way down the body like a North American road-switcher, gave the crew poor forward visibility in both directions of travel, although this was initially tolerated as it was no worse than the visibility from a steam locomotive cab. Despite these problems the class were more successful than the contemporary Type 1 locomotives of Class 16 and the later Class 17.

Withdrawal

With a decline in freight duties in the London area, and as a relatively small and non-standard class, the type was considered surplus to requirements by the late 1960s. All were withdrawn from capital stock between April 1968 and March 1971.

Conversion

All but four had been broken up for scrap by the end of 1972. The four that survived were converted into non-powered electric train pre-heating units at Doncaster Works, these duties keeping the locomotives employed for another ten years or more, until they were again made redundant and withdrawn.

Original Number	Departmental number	Location	Withdrawn	Disposal
D8203	DB968003	Finsbury Park (FP)	1981	cut up 1981
D8233	DB968001	Finsbury Park (FP)	1982	preserved
D8237	DB968002	Finsbury Park (FP)	1982	cut up 1985
D8243	DB968000	Finsbury Park (FP)	1989	cut up 1991

Preservation

One of the former train heating units, D8233, was purchased for preservation in 1984 and is now the only survivor of the type. It was originally kept at the South Yorkshire Railway in Sheffield, moving in 1986 to the East Lancashire Railway, and in 1988 to the Mangapps Farm Railway, where it remained until 1993. D8233 then moved to Crewe following an agreement with the Waterman Heritage Trust. Since its initial preservation the locomotive had received little work apart from cosmetic attention. Some work was carried out by the Waterman Heritage Trust, however the locomotive's restoration remained dormant until the end of 2005, when a reformed owning group, alongside the WHT, agreed the time was right to accelerate the locomotive's return to service. With an active plan for work agreed, the locomotive returned to the East Lancashire Railway in February 2006, where its restoration to working order is now under way.

Models

A ready to run model in 00 gauge was available from TechCad design based on a hand finished resin shell and powered by a Mashima motor. It was then available from TechCad as a kit, but TechCad have since ceased trading. Since 2010 Heljan have produced an OO gauge ready-to-run model in a variety of liveries.

An N gauge kit of a member of the class is available from BH Enterprises, powered by a Graham Farish Class 20 chassis.

An O gauge ready-to-run model is currently in production by Little Loco Company

Notes

Sources

• Stevens-Stratten, S.W.; Carter, R.S. (1978). British Rail Main-Line Diesels. Shepperton: Ian Allan Ltd. ISBN 0-7110-0617-2.
• Williams, Alan; Percival, David (1977). British Railways Locomotives and Multiple Units including Preserved Locomotives 1977. Shepperton: Ian Allan Ltd. ISBN 0-7110-0751-9.
• British Railways Locoshed Book 1977. Shepperton: Ian Allan Ltd. ISBN 0-7110-0752-7.
• 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.

Further reading

• McManus, Michael. Ultimate Allocations, British Railways Locomotives 1948 - 1968. Wirral. Michael McManus.

External links

• Class 15 Preservation Society, Owners of sole surviving Class 15, D8233
• Photograph of ADB968001, former D8233 at Stratford 12 September 1981