1957 marked a year of escalating change for British Railways. Although steam operation still accounted for huge segments of passenger and freight train operation in many areas of the country, inroads were being made with electric traction, diesel multiple units and the increasing fleet of shunting locomotives. The unveiling of the Modernisation Plan was by now well known with some of its details becoming reality. The introduction of the diesel multiple units was starting to gain momentum whilst the expansion of the fleet of diesel shunters had, by the end of 1957 reached a total of approximately six hundred in service. In the month of December 1957 the newest members of the standard 350bhp 0-6-0 diesel electric shunter were being delivered by several BR Workshops:
3404 - 3407 from Derby to the Western Region
Joining a small group of lower powered shunters were an increasing number of 204hp Gardner engined locomotives, during December 1957 the following were put into service:
2000 - 2003 from Swindon to the Eastern Region
Whilst the increase in size of the shunter fleet had been gradual and perhaps only truly noticed by the discerning traveller and the railway enthusiast community, it was during 1957 that the first Modernisation Plan mainline diesel locomotives entered service. Two types were introduced:
8000 - 8015 English Electric Type 1 Bo-Bo of 1,000bhp
These locomotives were allocated to depots in the London area, thus making themselves potentially visible to many members of the travelling public. Prior to their arrival the British Railways mainline diesel fleet totalled just seven locomotives (10000/1, 10201/2/3, 10800 and the Fell locomotive), many of which were increasingly relegated to secondary services or spending lengthy periods out of service. It is perhaps ironic that the first of the Modernisation Plan locomotives to be introduced, the Type 1/Class 20, would be one of the longest lived of the Modernisation Plan classes and would in fact continue to be ordered well into the 1960's to replace newer, 'standard' Type 1 classes that in the end proved to be a poor choice.
The Modernisation Plan orders for 171 mainline locomotives were placed during November 1955 with a further three being ordered during January 1956 at a cost of GBP11.4 million, with the first deliveries planned for the end of 1957. Allocations for the Regions were:
London Midland: 65 - all slow speed diesel electric
These programmes and proposals were contained in full in the Government White paper No. 9880, which dealt with the general position of the British Transport Commission, British Railways and the modernisation proposals as a whole. The original plan was to put these 174 locomotives into intensive operation and under careful observation. Until the trials were completed and the data reviewed the BTC would not allow the placing of any significant further locomotive orders. Once the data had been reviewed, then the orders would go out on a large scale. It was anticpated that by 1961 the annual locomotive orders would reach 200 per year for an indefinite period. These initial orders incorporated eight makes of engine from six private locomotive builders and two British Railways Workshops.
Elsewhere other private locomotive builders had spent 1957 working on their production lines such that North British & British Thompson Houston had locomotives ready for introduction early in 1958 as did English Electric whose 2,000bhp Type 4 would present a bold face to the batch of emerging higher powered locomotives. But beyond the publicity hoopla and the shiny new paint there lurked the beginnings of a period of unexpected disquiet for the British Railways Board and those responsible for the new diesel locomotives.
At the time of the drafting of the Modernisation Plan the number of manufacturers in the United Kingdom with the ability to produce railway traction engines was quite considerable. For political and other reasons the ordering of the locomotives and rolling stock was to be confined to domestic manufacturers. Although the engines of German and Swiss companies would power many British Railways locomotives, the vast majority of them were built under license in the United Kingdom.
The first of the mainline Modernisation Plan locomotives to enter service was the English Electric 1,000bhp Bo-Bo Type 1, later to become the Class 20 under the TOPS renumbering scheme.
English Electric Company
The Type 1 locomotive was powered by the English Electric 8SVT Mark II producing 1,000bhp at 850rpm.
The basic VT engine offered two banks of cylinders in Vee-form at 45 degrees, four-stroke with four valves per cylinder. The cylinder bore was 10 in (254mm) & piston stroke 12 in (304.8mm). Engines equipped with turbo-pressure-charging were denoted SVT, those additionally equipped with charge air cooling were denoted CSVT.
The eight cylinder 8VT model at 850 rpm produced 670bhp, the 8SVT 1,000bhp and the 8CSVT 1,133bhp. The largest in the series, the 16CSVT produced 2,266bhp.
In the United Kingdom the SVT engine featured in the pioneering LMS twins 10000/10001 of 1947/1948 which were powered by 16SVT engines, each producing 1,600bhp at 750rpm. Three further 16SVT engines were fitted to the BR Southern Region diesel electric locomotives 10201, 10202 & 10203, the first two rated at 1,600bhp, the latter at 2,000bhp. Quickly following on from the Type 1,000bhp locomotive came the English Electric Type 4 utilising the 16SVT Mark II of 2,000bhp at 850rpm. Slightly less powerful but probably more versatile was the English Electric Type 3 equipped with the 12CSVT engine producing 1,750bhp at 850rpm.
Such was the success of these three types (TOPS Classes 20/37/40) that a total of 736 were delivered to British Railways. When the decision was made to replace the 263 Mirlees, Bickerton & Day engines in the Brush Type 2's the English Electric 12SV engines rated at 1,470bhp was chosen.
The shortcomings of the early diesel-electric Type 4 locomotives, primarily either underpowered or overweight led to the private manufacturers building lighter, higher powered one-off demonstrators in the hopes of picking up future orders from British Railways. English Electric delivered their locomotive, DP2 for trials during 1962, powered by a 16CSVT engine producing 2,700bhp. The locomotive did not attract any immediate orders, Brush were selected to build the standard Type 4 powered by a Sulzer 12LDA28C engine.
Although DP2 produced no immediate orders a class of fifty locomotives were introduced by English Electric in 1967 powered by the 2,700bhp 16CVST. These Type 4 locomotives, later the Class 50, were initially on hire to British Railways primarily for use in pairs on the West Coast Mainline north of Crewe as a stop gap meaure prior to the completion of the London - Glasgow electrification.
When steam was finally retired in 1968 and the vast majority of the Moderisation Plan locomotives had been delivered, the Sulzer powered locomotives ranked number one in powering the BR mainline diesel fleet. However if the British Railways fleet of diesel shunting locomotives was included in the equation then English Electric clearly won the day.
EE 16SVT 1,600bhp at 750rpm: 10000, 10001
Early in 1934 R & W Hawthorn Leslie & Co Ltd delivered an 0-6-0 diesel electric shunter powered by an English Electric type 6KT engine producing 300bhp at 680rpm. This would later become LMS 7079 & (BR) 12002 and along with Armstrong Whitworth shunter LMS 7408 formed the basis of the large number of 350bhp 0-6-0 shunters that followed. Ten locomotives built for the LMSR in 1935 next carried the 6KT engine, this model engine would be used for similar shunters built for the LMSR & BR including nearly all of the huge Class 08 fleet built during the 1950's & early 1960's. It was also used in similar shunting locomotives delivered to private industry and railways overseas.
EE 6KT 350bhp: 15100
The second series of mainline locomotives to be introduced were the Brush Type 2 locomotives which were delivered to the Eastern Region.
Mirlees, Bickerton & Day Ltd
The engine fitted to the Brush Type 2 was the twelve cylinder JVST12. The JVT model was available with 12 or 16 cylinders producing 620bhp to 2,006bhp running at 500rpm to 900rpm. The use of pressure charging was indicated by 'S' in the model type. A total of 263 Brush Type 2's were powered by the JVST12 model, the only Class of locomotives on British Railways to be powered by a Mirlees, Bickerton & Day engine. The first twenty locomotives (D5500 - D5519) were rated 1,250bhp at 850rpm, D5545 was rated 1,600bhp at 950rpm and D5655 - D5670, D5835 at 2,000bhp. All the remainder were rated 1,365bhp at 900rpm.
Despite the lengthy experience of this manufacturer producing diesel engines for a variety purposes, the reliability of those fitted to the Brush Type 2's became of great concern to the the operating authorities and railway management. Eventually the decision was made to repower the whole Class with the English Electric 12 cylinder 12SV of 1,470bhp. D5677 was the first to be re-engined during 1964.
Mirrlees JSV12T 1,250bhp at 850rpm: D5500 - D5519 (20)
If 1957 was the year that brought the first Modernisation Plan diesels into service then 1958 saw the floodgates open. Arriving very early in 1958 were the first members of the NBL/MAN powered 2,000bhp Warship Class locomotives.
North British Locomotive Company
NBL had ventured into the diesel locomotive about 1948 but not with the intent to build the power units or the transmission equipment. However in 1951 a license was obtained for the manufacture of Voith hydraulic drives which were initially used in the small diesel shunters built by NBL. In 1954 a licence was acquired to build medium speed and quick running MAN engines, though at the time no pending orders required a MAN engine.
The five North British A1A-A1A Type 4 Warship locomotives were powered by two NBL/MAN 12 cylinder type L12V18/21S of 1,000bhp each. The designation translated L:(lightweight) 12:(number of cylinders) V:(vee form) 18/21: (stroke/bore in cm) S: (supercharging). This engine was designed for a high power output with a lightweight design. The MAN engine and the Voith transmission were the heaviest of their types when compared to the three engines types available in Germany and in comparison with the Mekydro transmission. Thus even from the outset the NBL product had moved away from the Western Region concept, not by their own engineers but those from the BTC mechanical engineering staff. The L12V18/21S engine was also used in the 58 North British Type 2's with electric transmission built for use by the Scottish Region after they were used briefly on the Eastern Region in the London area. The last twenty were uprated to 1,100bhp. The L12V18/21M engine was fitted to 58 North British locomotives equipped with hydraulic transmission for use on the Western Region. The first six were rated at 1,000bhp, the remainder at 1,100bhp.
An uprated engine, the L12V18/21BS of 1,100hp was used in pairs in Warship Class locomotives D833 - D865.
The longterm outlook for the life expectancy of these locomotives suffered two major setbacks, when firstly the North British Locomotive Company went into bankruptcy and closed its doors and secondly the decision by British Railways to prematurely retire those mainline diesel locomotives equipped with hydraulic transmissions.
Several of the shunting locomotive classes introduced as part of the Modernisation Plan were also equipped with NBL/MAN engines. In 1957 an NBL 0-4-0 shunter was introduced utilising the NBL/MAN W6V 17.5/22A engine producing 225bhp at 1,100rpm. These were numbered D2708 to D2780 (the first twelve were originally numbered 11708 - 11719). The following year the NBL/MAN W6V 17.5/22 AS engine was used to power the shunter class numbered D2900 to D2913. These two shunters classes did not have the longevity that was perhaps expected of them. For D2708 - D2780 all had been retired by February 1968, four were sold into further industrial service, two of which eventually reached preservation. D2900 - D2913 were all retired during February 1967 and scrapped by the end of the year.
NBL/MAN L12V 18/21S 1,000bhp: D600 - D604 (5)
Another arrival early in 1958 was the British Thomson-Houston Bo-Bo Type 1 powered by a Paxman 16 cylinder engine.
Davey Paxman & Co Ltd
For the D8200 & D8400 series locomotives the Paxman 16YHXL engine producing 800bhp at 1,250rpm was utilised. This range of engines, the RPH for normally aspirated and the YHX with pressure charging were available with four to sixteen cylinders producing 133bhp to 1,000bhp with the rpm ranging from 600 to 1,250. These engines were of 'V' form, with a bore of 7.0in and a stroke of 7.75in.
These Modernisation Plan locomotives drew some of their design from Paxman engined locomotive No. 10800 which was equipped with 827bhp 16RPHX engine. Its first three years in service had produced an availability of 84% in freight transfer work.
The small size of these two locomotive classes affected their longevity. The North British built D8400 series were all retired by September 1968 and scrapped by the end of 1969. The D8200 series faired a little better, with many surviving in service until March 1971. Four went on to serve as carriage heating units, of which two were later preserved.
Paxman engines also featured in some of the Modernisation Plan shunters. The North British built 0-4-0 class introduced in 1953, numbered 11700 - 11707 (later D2700 - D2707), were powered by the Paxman 6RPH of 200bhp at 1,000rpm. The Ruston & Hornsby series of shunters numbers D2985 - D2998, introduced in 1962 carried the 6RPHL engine.
Pairs of Paxman 6ZHXL engines rated at 450bhp at 1,500rpm were used in the Clayton Bo-Bo Type 1's D8500 - D8616 introduced in 1962.
Paxman 12YJXL 1,200bhp at 1,500rpm: D830
Another small group of locomotives which arrived in 1958 were the Metropolitan Vickers Co-Bo Type 2 locomotives powered by a Crossley HST Vee 8 producing 1,200bhp at 625rpm.
Crossley Brothers Ltd
The HST Vee series was available with six to sixteen cylinders producing 1,030bhp to 2,760bhp at 300rpm to 650rpm. The confidence in these locomotives saw pairs of them used in the overnight London - Glasgow 'Condor' expedited freight service. The spotlight for them on this prestige service quickly faded as their reliability faltered. After several years of mediocre service they returned to the manufacturers for repair work. They re-entered service in the North west/Cumbria on secondary services, the final examples were withdrawn in September 1968, only one month after steam finished on British Railways. One example survived into preservation.
The problems encountered centered primarily around the Crossley engine and was not restricted to the British Railways locomotives, the Western Australian Goverment Railways (WAGR) X & XA classes and the Irish Railways (CIE) Crossley powered locomotives also presented similar failings. At a high level the problems were two-fold; that of the manufacturer entering the expanding railway traction market with a new and unproven design and that of the nature of railway operations themselves - the compromise between axle loading, weight & power and the ever present effects of vibration.
Crossley ESNT 6 350bhp at 825rpm: D3117 - D3126
Bristol Siddeley Engines (BSE)
The Swindon order books now contained orders for the three Modernisation Plan Type 4's (D800 - D802) and the thirty follow-on Type 4's (D803 - D832) ordered in February 1957. In order to avoid any suggestion of a bias towards buying German, an equivalent number of 33 Type 4's were ordered from NBL (D833 - D865), although as mentioned elsewhere these would have MAN engines and Voith transmissions. Since the Western Region had been looking for 70 Type 4's the final five (D866 - D870) were to be built at Swindon.
The next orders for BSE involved the mixed traffic diesel hydraulic Hymek Type 3 Bo-Bo locomotives equipped with a single 1,740hp MD870 16 cylinder engine and Mekydro hydraulic transmission. Swindon's order books received their last mainline locomotive order with the placement of 74 Type 4 Western Class locomotives powered by two 12 cylinder MD655 engines coupled to Voith transmissions.
Two Maybach MD655 engines were built for the Brush prototype locomotive D0280 Falcon.
MD650 1,056bhp at 1,400rpm: D800 - D802 (3)
Sulzer Brothers (London) Ltd
Sulzer 6LDA28 1,160bhp at 750rpm: D5000 - D5150 (20)
The above seven manufacturers (or their licensees) would provide engines to power the 174 mainline locomotives ordered under the 1955 Modernisation Plan, and many more when the constraints of the Plan were removed. From the tabular listings under each maker it is relatively easy to see which would become the preferred engine types, though not necessarily always the most succesful when all was said and done.
Blackstone & Co Ltd
Although Blackstone engines did not power any of the Modernisation Plan mainline locomotives they were used in six orders for the standard 0-6-0 350bhp diesel shunting locomotives.
Blackstone ER6T 350bhp at 750rpm: D3137 - D3151
These shunters were later considered non-standard, leading to early retirement during 1967 - 1971. Several saw further service in industrial use and at least two reached preservation.
The carefully crafted Modernisation Plan with its plan for comprehensive testing and careful selection of locomotive types quickly fell by the wayside. As the first of the Modernisation Plan locomotives were entering traffic the placing of further orders commenced. These orders would eventually see the delivery of twenty two different classes plus an additional variations, a far cry from the initial intent.
Well, to be honest I started this page uncertain where it was going or what it was supposed to cover. For the moment therefore its an unfinished work pending further inspiration.
British Diesel Engine Catalogue, 4th Edition (1957): published by The British Internal Combustion Engine Manufacturers Association, London; editor D S Dodsley Williams.