British Rail Class 17

The Type 1 was the lowest power classification for BR mainline diesels. Under BR's 'Pilot Scheme', three different designs of Type 1 locomotive had been produced. Two of these (Classes 15 and 16 under the TOPS classification system) had a layout based on the 10800 prototype, with a single off-centre cab and full-height engine covers, from which forward visibility for the crew was poor in both directions of travel, while the third (Class 20) had its cab at one end, giving good visibility in that direction only.

Having gained experience with these types, although Class 20 was widely considered to be a technical success, BR decided that it would be desirable to have a single-cab Type 1 locomotive that provided good forward visibility in both directions. The organisation thus approached various locomotive manufacturers with its request for proposals to meet its requirement.[1] Amongst those companies that chose to respond was the British manufacturing interest Clayton Equipment Company, which had already acquiring considerable experience in the design and production of various mechanical elements of existing Type 1 locomotives, and was keen to pursue its own design. Following a review of submissions, BR opted to select Clayton's submission, ordering 117 locomotives off the drawing board, and announced to the railway press that these locos were to be the new Type 1 standard.[2]^:59

Between September 1962 and February 1965, production of locomotives D8500-D8587 was performed in house by Clayton, while subcontractor Beyer, Peacock and Company of Manchester delivered D8588-D8616 between March 1964 and April 1965.[1]

The Class 17 locomotive incorporated several features that were relatively novel amongst its contemporaries; to achieve the desired visibility from a single cab, it was decided to place it in a central position and use relatively low engine bays.[1] This arrangement heavily contributed to a key design choice; despite the widespread availability of engines capable of generating sufficient power on their own, the propulsion arrangement opted for was a pair of relatively small six-cylinder horizontal engines, each being placed on either side of the cab. According to the manufacturer, the increased maintenance costs of two engines over a single unit was a worthwhile tradeoff for the improved visibility enabled by such an arrangement.[1]

The majority of Class 17s were powered by a pair of Paxman 6ZHXL engines of 450 hp (340 kW) each,[3] an engine originally intended for diesel railcars, but not adopted.[4] The last two of the Clayton-built batch, D8586-D8587, each had a pair of Rolls Royce Type D 450 hp (340 kW) engines. These units also suffered several crankcase failures, leading to two of the four being replaced by Paxman units.[5] The propulsion arrangement also featured an electric transmission, rather than a hydraulic counterpart; this was a somewhat unusual design choice for the era as the vast majority of contemporary twin-engined locomotives had opted for hydraulic tranmissions.[1]

Fuel was supplied from a single tank mounted in a central position.[1] To prevent overfilling of the tank, an auto-cutoff system was integrated; several other warning systems, such as the fluid level of the radiator header tank, were also present. A total of four GEC WT421 traction motors, each rated for 157 hp of continuous power at 480 rpm, delivered power to the wheels via a 15/66 reduction gear.[1] All four motors could be driven by a single engine, if desired by the driver. The motor armatures were highly balanced to reduce vibration levels; further features included for operational convenience and safety were a relay-based automatic wheelslip detection system, which reduced power without driver intervention, and an automated fire-suppression system that discharged bottled carbon dioxide into the applicable engine bay if excessive temperatures were detected.[1]

The cab features two identically-configured driving positions, one facing in either direction.[1] Large armor plate windows cover the majority of the forward and rear cab walls; in combination with sliding side-facing windows, these provide a high level of exterior visibility to the driver. The cab itself with largely built out of steel, with the space between the interior and exterior surfaces was lined with fibreglass and other materials for both soundproofing and heating purposes.[1] While not included in BR's requirement, the manufacturer opted to include provisions for a steam boiler to be installed in the cab area; this was to enable the Class 17 to potentially haul passenger services, which would require heating to be generated by the locomotive. In addition to steam heating, electrically-heated carriages could also be handled by the type.[1] The Clayton-built Class 17s had 'red diamond' control equipment, while the Beyer Peacock batch had the standard 'blue star' type. A maximum of three Class 17s could work in multiple with one another, as well as other types.[1]

The superstructure is divided into three distinct sections, the cab and the two equipment casings.[1] This is borne upon an underframe, which is entirely composes of welded steel and featuring full-length deep-section longitudinal beams, having been designed to withstand buffeting forces of up to 200 tons. Jacking and lifting brackets were incorporated as to better facilitate maintenance and static transportation of the locomotive alike.[1] Several pieces of equipment, such as the lead acid batteries, were accommodated beneath the underframe Provisions were also made for the installation of a standard BR snow plough.[1]

D8568 arriving from Kidderminster

After withdrawal in 1971, D8568 went on to see industrial use at Hemelite, Hemel Hempstead and at Ribblesdale Cement, Clitheroe, and was then secured for preservation.[7] It is now (2018) at the Chinnor and Princes Risborough Railway, Oxfordshire.[8]

In the Thomas the Tank Engine and Friends TV Series, a character based on this class appears by the name of Derek, with the problems inherent to the class incorporated into the character and his sole episode.[9]

Danish manufacturer Heljan launched a 00 gauge ready-to-run model of the Class 17 at the 2006 Warley National Model Railway Exhibition which went on sale after some production delays in early 2009. Aside from small runs by TechCad, and in kit form by DC Kits and others, this was the first time the class had been produced as a ready-to-run model.

In November 2018, Heljan announced production of an O gauge version for release in late 2019.

In August 2020, Bachmann announced the imminent release of an N gauge model under their new "EFE Models" brand; to be available in various liveries: BR green with small yellow panels, BR green with full yellow ends, BR blue with full yellow ends, and Ribble Cement green and white livery.

• Clough, David N. (2009). "Class 17". British Rail Standard Diesels of the 1960s. Ian Allan. pp. 14–21. ISBN 978-0-7110-3373-3.
• 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.
• Cayless, David (June 1982). "Day of the Claytons". Rail Enthusiast. EMAP National Publications. pp. 26–27. ISSN 0262-561X. OCLC 49957965.
• Brown, Murray (March 1983). "Clayton is safe at last...". Rail Enthusiast. EMAP National Publications. p. 45. ISSN 0262-561X. OCLC 49957965.

Wikimedia Commons has media related to British Rail Class 17.

• "The Class 17 Claytons - BR's Standard Type 1?" (Rail Blue .com)
• "The Only Class 17 Clayton left Running here" at Chinnor and Princes Risborough Railway Association