One of the most fondly remembered British Rail diesel locomotives was the English Electric Type 4, later christened Class 40. Nicknamed ‘Whistlers’ by rail enthusiasts, due to their distinctive engine noise, it was at one stage the star of the British Railways diesel fleet, hauling top line expresses in the east of England and on Anglo-Scottish routes.
However, it was hardly the most outstanding performer, and by the mid-1960s it was being relegated to less prestigious trains as more powerful diesel designs became available. The origins of the Class 40 date back to the late 1940s and the dying days of the London Midland and Scottish railway.
The LMS, in conjunction with English Electric, designed a new class of diesel locomotive. Powered by a 1600hp English Electric 16SVT engine with diesel-electric transmission, the first locomotive, numbered 10000, entered service in December 1947. By the time its sister locomotive, 10001 had been constructed, the LMS had become the London Midland Region of the newly-nationalised British Railways.
The LMS had intended to compare its new diesel twins with its latest steam locomotives. For the heavily-loaded West Coast Main Line, the plan was to run the diesels in pairs so as to compare them with the mighty William Stanier-designed Pacifics. Back in 1939, an LMS Pacific had recorded a power output of 3300hp, thus explaining the logic of pairing two 1600hp diesels.
In 1948, the LMR tested 10000 and 10001 on a London to Glasgow express. Such was the hitherto unmatched acceleration of the duo that the train was eased off. Despite having BR’s Chief Mechanical Engineer, R.A. Riddles, on board, the decision had already been taken to build yet more steam locomotives.
The next stage in Britain’s embryonic diesel development was conducted by the Southern Region of British Railways. Shortly before nationalisation, the Southern Railway in conjunction with English Electric, had begun to design their own diesel locomotive, using the same 1600hp engine utilised in the LMR twins. The major difference in the designs was in the wheel arrangement.
Train 10000/10001 used a six-axle layout, or co-co, to use railway parlance. The three SR locomotives used an extra pair of wheels on each bogie, known as 1 co-co 1 layout, for better weight distribution. The first two SR locomotives, 10201 and 10202, entered service in 1950-’51. In 1954, a third member of the class, 10203, entered service. This example had its engine uprated to 2000hp and this formed the basis of what became the Class 40.
As part of its 1955 modernisation plan, British Railways ordered ten diesel locomotives from English Electric based on 10203. The bodywork was much changed, gone was the forward control cab of the Southern Region examples. The first ten English Electric Type 4 diesels, as they were then known, were sent to the Eastern region of British Railways.
They made their debut on the Great Eastern Liverpool Street to Norwich line in April 1958. With their 90mph top speed and loads of around ten coaches, performance was adequate but not spectacular. They had to compare with the Britannia Pacifics that could hammer through Diss at 94 miles per hour. However, the ‘Whistlers’’ performance was satisfactory enough to result in orders for a further 190 locomotives.
That same year the English Electric Type 4s were put to work on the Kings Cross to Edinburgh route. It was on this route that the English Electric Type 4s had to stand comparison with British Railways racehorses, the Nigel Gresley-designed A4 Pacifics – although 35 of the Pacifics had been produced, only the last four had been fitted with double chimneys.
One of these four, 4468 Mallard, had in 1938 set a world record for steam traction, 126 miles per hour, that still stands to this day. It took until the late 1950s for BR to convert the remaining 31 A4s to double chimney configuration, but these revitalised giants of steam set a benchmark in performance that the 90mph ‘Whistlers’ struggled to match.
This was exposed by the all too frequent diesel failures in the early years of use. A dirty, unkempt steam locomotive usually had to be substituted to make up for lost time. Whilst a diesel locomotive could out accelerate a steam locomotive, the English Electric Type 4 was restricted by its gearing to 90 miles per hour. A steam locomotive could be wound up to speeds in excess of 100mph and sustain such pace.
The plus points of a diesel locomotive was its switch on and off availability, whereas a steam engine needed long-winded preparation before it could perform its daily roster, and then more maintenance at the end of its working day.
Sir Brian Robertson, Chairman of the British Transport Commission, was less than impressed with the English Electric Type 4, believing that the locomotives lacked the power to maintain heavy trains at high speed and were too expensive to run in multiple – opinions that were later proved to be correct. Airing his views at the Regional Boards prompted others to break cover and it was agreed that later orders would be uprated to 2500 hp, a change that was never applied.
The dawning reality that the ‘Whistlers’ were no journey shrinkers in a Britain about to enter the motorway age, was compounded by the alarm of the Macmillan Government at the projected cost of electrifying 29 per cent of Britain’s railways by 1980.
The Government scaled back on rail investment and dieselisation became the order of the day. The more savvy Eastern Region management, realising that 90mph speeds simply would not do, and that their lines were not going to see powerful and lightweight electric traction any time soon, pushed for a production version of the 3300hp Deltic diesel, the prototype of which had been operating on British Railways since 1955. As a consequence, they declined to accept any more English Electric Type 4s, and their allocation was transferred to London Midland Region.
LMR assigned their ‘Whistlers’ to the West Coast Main Line, Euston to Glasgow or Holyhead. Hauling 13 or 14 coach trains, they had the unenviable task of replacing the might Duchess Pacifics, steam engines designed to cope with the gradients north of Crewe. However, this did enable LMR to withdraw its ex-LMS Pacifics, this task being completed by the end of 1964. It was in 1963 that D326 became the most famous English Electric Type 4, when it was the locomotive stopped during the Great Train Robbery.
Any hopes that the ‘Whistlers’ would be short-term stopgaps pending Euston-Liverpool/Manchester electrification were dashed as this took until 1966 to reach fruition. The last English Electric Type 4 was delivered in September 1962, by which time the design was considered to be at 133 tons, overweight and underpowered.
The heyday of the ‘Whistlers’ was the early 1960s, but by the middle of the decade the Brush Type 4, a lighter 2750hp co-co design was available and it began to supplant the older English Electric design. In 1966 100mph electric trains replaced the diesels south of Crewe, although the route to Holyhead remained diesel hauled.
LMR, realising that they were stuck with diesels for some time north of Crewe, acquired fifty 2700hp Class 50 diesels, and the ‘Whistlers’, now re-branded as the Class 40, were relegated to less prestigious duties. Gradually the 200 strong fleet were repainted from their original green to Rail Blue and renumbered. After their initial teething troubles, the class settled down to become reliable performers. The last examples were withdrawn in 1985 and seven Class 40s survive in preservation. D326, later renumbered 40126 was scrapped in 1984. British Rail made sure it was not one of the preserved examples.
Now the pictures… First we see D335 in green (below), hauling a rake of maroon coaches in 1964. Then we have the now preserved 40122 hauling a freight train in the Rail Blue era (top). Train 40122 was originally numbered D200, the first of the class.