BR’s traction plan
The first National Traction Plan for diesel locomotives was produced in 1964, and was updated periodically by British Rail. DAVID CLOUGH looks back 40 years to the proposals under consideration in 1978
travels back to 1978, to study the proposals under consideration as part of the National Traction Plan for diesel locomotives.
British Rail’s diesel fleet totalled 2,280 in 1978, and the nationalised railway service had accepted a dual-strand traction policy for the needs of the passenger and freight businesses. For the former, the 1978 Rail Plan was based on 115 High Speed Train (HST) sets by 1983 and 164 diesel Advanced Passenger Trains (APT) by 1993.
Electrification schemes assumed to be completed were St Pancras to Bedford, Liverpool Street to Norwich and Cambridge, and certain ancillary lines attached to the West Coast Main Line. Diesel locomotive requirements were forecast as follows: locomotive renewal for 25 locomotives per year from 1979 to 1982.
Nine months later, however, the DTp was not satisfied that the freight business was generating sufficient profit to justify a higher rate of renewal annually. It questioned whether it would be better to refurbish a quantity of Class 47s at £ 200,000 per locomotive for a ten-year life extension, rather than build Class 56s at £ 600,000, with resultant cash flow savings.
Having been referred to by the DTp, and by virtue of the fleet size and therefore its significance, the situation with Class 47s needs to be reviewed in detail.
On the evidence available back then from the HGR programme, the engine lives could not be extended for a second time without another heavy repair when many components would require re-machining - the feasibility of which was doubted. Taken together with problems with the main and train heating generators, it was considered that new power units would be required, rather than just new cylinder blocks and crankcases.
The traction motor suspension tubes were already in trouble and a new design of individual suspension units would be required for each side of the motor. The main generators had overheating problems and these, and other electrical machines, would need further heavy repair.
Cost estimates for this work, which would afford a further five years working life, approximated to £120,000 per locomotive, assuming many were to be life-extended. There was also the strong possibility of expenditure on structural repairs which had not been costed.
The foregoing highlights a frequent issue that ran through BR’s planning, namely the widely differing estimates of the variables integral to the planning process. While the DTp was basing its thinking on a Class 47 life extension costing £ 200,000 and giving an extra ten years, BR’s assessment was a cost of £120,000 for five extra years. Of course, the DTp figures could only have originated from BR!
BR’s view was that this life extension work merely deferred withdrawal and it is clear the Railways’ view was it was poor value, when compared with the planned 30-year life of a Class 56. From a DTp standpoint, the life extension option meant there was a reduced capital outlay, which would please HM Treasury.
The service had begun to look more closely at life extension across its diesel fleet in 1977, and drew up a set of proposals. A surprising feature deemed essential was cab airconditioning. These proposals are summarised below.
Class 25: Cracked engine cylinder blocks and crankcases and heavily-worn main generator commutators were the principal issues. A replacement auxiliary generator was envisaged to facilitate cab air-conditioning, extra traction motor cooling and possibly an electric train supply. Fitting a replacement engine to 200 of the fleet of 300 was put forward, with cannibalisation for the remaining 100. The traction motors needed major attention to deal with overheating.
Class 31: The electrical control gear was a
problem and required significant maintenance. While the electrical machines were satisfactory and receiving a half-life rehabilitation, the traction motor suspension tubes (as with Class 47) were a problem in need of a solution.
Class 33: The same issues facing other Sulzer engines fitted in BR diesels applied here.
Class 37: Nothing beyond routine work was envisaged. The electrical machines were receiving a half-life rehabilitation.
Class 47: The work needed here has been described already. A second heavy repair, involving machining, was considered impractical for some parts of the Sulzer engine and, taken with problems with the main and train heat generators, the proposal was floated of fitting a complete new power unit when the next heavy repair became due. Class 50: Heavy repairs to some of the electrical machines and rewiring were all that was proposed for a life extension of six to seven years. The above demonstrates a clear dichotomy between English Electric (EE) engine types and those of BR Derby design with Sulzer engines. While BR’s engineers had favoured the more expensive Sulzer diesels when orders were placed in the late 1950s and 1960s, the EE engines, described at the time as crude, had proved to have superior longevity for a lower capital cost.
In December 1978, the CM&EE gave his thoughts to the Board’s chief investment officer. He was concerned that British Rail Engineering Ltd (BREL) workshops were falling behind their new-build programme for HST power cars, EMUs and five Class 56s. In the same month, a submission was made to BR’s investment committee, whose decisions went to the BR Board for final approval, to authorise an additional 37 Class 56s. Earlier
In August 1977, the Department of Transport had approved a rolling programme of locomotive renewal for 25 locomotives per year from 1979 to 1982.
debate had proposed a build of 50, then 74, before settling on the lower figure. The submission also sought authority for an annual rolling programme of 50 new Type 5 freight locomotives beyond 1982.
The submission envisaged that Class 56s would continue to be built until 1982-83, when a new design was expected to be available. Also under review was the procurement of ready-built locomotives but no mention was made of foreign designs.
The new design referred to was Class 58s. By 1978, designs were already well advanced for a refinement of Class 56s that would produce greater reliability at a lower capital cost. The plan was that Lot 1510 for 80 locomotives of the 170 already authorised should be divided between 45 Class 56s to be built at Doncaster and 35 Class 58s to be built at Crewe.
The position in 1978 with Class 56 orders was for 60 in September 1974, 30 in August 1976 and 80 in August 1977. If a rolling build programme of 50 annually were not now authorised, then by 1988 the forecast build would rise to 160 per year to replace lifeexpired traction while continuing to meet traffic requirements.
Railway politics then came into play. Concluding Class 43 HST power car construction at Crewe gave the potential for a Type 5 production line to be set up there. In other words, there would be trade union issues unless the Crewe workforce was kept occupied. The position would be exacerbated if, by 1988, the forecast bulge of 160 new locomotives could only be met by ordering at least part of this quantity from abroad, even if the overseas supplier quoted a lower price than BREL.
To illustrate prevailing and planned output, during 1978 Doncaster had built 15 Class 56s, against a target of 22. For the four years from 1979, the target was now to be cut from 25 to 20 units annually. A private contractor would not have been allowed to get away with such slippage - hefty liquidated damages would have been levied but BREL avoided penalty for late delivery.
Yet again, two sets of forecasts were at odds. Here Doncaster’s target has been cut to 20, but the submission to the investment committee was still 25 locomotives annually.
The submission also detailed the options for extending the life of the existing fleet as an alternative to the proposed rolling programme. But BR couldn’t be consistent with its estimates. For wider consumption, life extension would give an extra five years beyond book life but internal documents were more optimistic. Of course, such life extension merely deferred, not avoided, the need for replacement.
According to the submission, life extension was regarded generally as unwise because of uncertainty about the risks of factors such as component obsolescence. Quoting from the paper on a way forward: “In the context of a
Options for extending the life of the existing fleet as an alternative to the proposed rolling programme were detailed. But BR couldn’t be consistent with its estimates.
continuing viable freight business a modest renewal programme backed up as necessary by selective life extension is considered the course most likely to maximise performance and minimise the risk of abortive expenditure or inability to carry the profitable business available.” Not a comma in sight and no explanation of what a modest renewal programme would entail!
There is something of an irony in that the submission argued that deferring new construction would deny the businesses new technology and enhanced performance. The deferment that did happen avoided saddling the businesses with technologically outdated BR-designed Type 5s and delivered a much more puissant traction unit in Class 60s a decade later, albeit at the cost of a dreadful settling-in period.
In the event, the DTp rejected the two arguments put forward by the submission. Approval came for just an extra 15 Type 5s, which were built as Class 58 and the rolling renewal programme did not materialise.
Faced with its desire for new locomotives being turned down, in February 1980 BR produced a class-by-class life expectancy for its fleet and this is set out here.
Quantities for Classes 25, ‘31’, ‘45’ and ‘47’ comprise all locomotives of the type. A note to the above says withdrawals in any given year will be determined by financial limits on the cost of a repair and also the need to provide spares for others in the class. Life extension of up to 350 Class 47s between 1989 and 1993 had been assumed for planning purposes.
In May 1980, a submission to build HSTs for the Midland Main Line was refused. Consideration was given instead to the use of either Class 47s or ‘50s’ fitted for push/pull operation. Installing a new GEC Diesels engine into Class 50s was floated but never progressed.
So, what did happen? Class 20s survived into the 1990s as planned and without any major remedial work, a remarkable testimony to EE design philosophy. The only attention given to Class 25s was a major depot exam in 1985 to 12 locomotives to give a modest life extension but the remainder were taken out of traffic. Similarly, Classes 40, 45/ 0’ and ‘46’ received no attention and lasted just for their booked lives.
Class 26s, some Class 27s and most of Class 31s were put through a heavy general repair during the second half of the 1980s. 135 members of Class 37s underwent more extensive refurbishment and limited re-engineering to extend their lives by at least ten years.
Class 45/1s and ‘47s’ received HGR work during the late 1970s and early 1980s. Despite the conviction of the CM&EE in 1978 that the ‘47s’ power unit would need further major surgery of replacement by the late 1980s, a significant number remain in regular service today without any refurbishment.
Class 50s were also refurbished over four years from 1979 but became surplus a decade later by newer forms of traction and a transfer of duties to Class 47 released from other diagrams.
About the author David Clough, Contributing Writer
David Clough has been writing for RAIL on traction-related topics since January 1983. He is the author of 14 books about Britain’s railways.