Two western region diesel hydraulic locomotives inside the new diesel shed
D1000 ‘Western’ class introduction
‘Western’ class number D1013 Western Ranger The ‘Western’ class diesel – hydraulic locomotives came into being due to the introduction of Krauss – Maffei’s experimental ML3000 3,000 bhp locomotive. This German design used the same Maybach MD650 engines and Mekydro K184 transmissions as used in the Swindon built ‘Warship’ class, but uprated to 1,500 bhp. Although details of the ML3000 were sent to Swindon for consideration, the Western Region decided to design their own locomotive from the ground up. Based around Maybach MD655 engines of 1,380 bhp and Voith L360rV transmissions, the body used the stressed – skin method of construction so successfully employed in the D800s. Voith transmissions were specified as Mekydro units were required for the ‘Hymek’ class and this decision was also made to spread the workload among the various suppliers. All of the engines though would be built by Bristol Siddeley Engines from their plant at Ansty, while 103 transmissions would be supplied by the North British Locomotive company and Voith Engineering of Glasgow with another 60 sets produced in Germany.
The order for 74 locomotives was placed by the British Transport Commission in September 1959 just prior to the completion of the final design. Construction was to be split between Swindon, who were to build the first 35 ‘Westerns’, and also Crewe who were to built the last 39. Various problems with the final design details meant that the first member of the class was not delivered Maybach MD655 engine until December 1961, and so to relieve pressure on Swindon, the decision was taken that the last 5 of the locomotives due to built there, would be constructed at Crewe instead. Therefore, Swindon built ‘Western’ numbers D1000 – 29, while Crewe built numbers D1035 – 73 and D1030 – 4 in that order.
Initially the class were to be named after West Country beauty spots and the suggestion was that number D1000 was to become ‘Cheddar Gorge’ before this proposal was dropped in favour of the ‘Western’ names. The class also became the subject of various livery experiments. The first ‘Western’, D1000 Western Enterprise, was outshopped in a unique desert sand livery with wheels, roofpanels, bogies and window frames in black. Buffer beams and front skirts were painted in carmine red. The second ‘Western’ locomotive, D1001 Western Pathfinder, was delivered in a maroon livery with window frames in white while the buffer beams and front skirts were in yellow. The next three locomotives, D1002 – 4, were painted in the traditional Brunswick Green but with small yellow panels applied around the headcodes. The first Crewe built ‘Westerns’, D1035 – 8, were similarly painted. There then followed a public competition to decide the most popular livery (yes, British Railways did ask the public for their opinion sometimes) and the winning colour that the public chose was maroon. Other examples of the class were given this livery together with the small yellow panel around the headcode. One exception to this was number D1015 Western Champion, which was outshopped in a livery described as Golden Ochre with the buffer beams painted in red.
In Service.
As stated, D1000 ‘Western Enterprise’ Voith L630rV hydraulic transmissionentered traffic in December 1961 and was soon sent to Plymouth Laira for trials, while in February 1962, D1001 ‘Western Pathfinder’ was chosen for various trials against the prototype of what would become the Class 47’s, D0280 ‘Falcon’.
Within a month, the first signs of a bogie design fault appeared and it was found that soft suspension between the bogies and the body frame on D1000 created excessive movement of the cardan shafts that transmit the drive from the engine to the transmission. This movement weakened the cardan shaft joints and also set up stresses within the transmission. D1001’s transmissions were also inspected and the same amount of wear was discovered. Stiffening and repositioning the’Western’ class locomotive in the popular maroon livery torque reaction arms effected a temporary repair, however in 1963, a return of the unsatisfactory riding qualities meant that all but four of the class were restricted to 80 mph. A programme of bogie modifications, including replacing the rubber side blocks with metal fittings, was begun and by April 1964, 50 members of the ‘Western’ class were restored to working at 90 mph.
Many of the mechanical problems that effected the ‘Westerns’ were related to the train heating boiler, but also problems were found with the compressors and exhausters, dynostarts and engine fuel pumps. Many of the faults were blamed on Bristol Siddeley Engines who manufactured the Maybach engine under licence, and in some instances, materials appeared to have been used which were not to the design specification. One example of this was the compressors lower central shaft roller bearing which had a cheaper alternative installed, while on some of the crankcases, the wrong type of welding rod had been used in its construction.
One unusual design problem on the ‘Westerns’ concerned the windscreen wipers when in use at high speed. Numbers D1006 ‘Western Stalwart’ and D1039 ‘Western King’ were fitted with experimental rotary wipers of a design used on ships. Although these type of wipers swept away the water, they produced an opaque film on the windscreen and this restriction to the drivers vision cancelled the project.
By the late 1960’s, apart from one or two engine problems, the ‘Westerns’ were giving sterling service. The bogies were giving 150,000 miles between general repairs while the Voith transmission was shown to be a more reliable unit compared to the Mekydro transmission on the ‘Warships’. The class soldiered on into the early 1970’s due to the unavailability of the English Electric Class 50, and as maintenance staff had been told to keep the ‘Westerns’ running without major repairs, it was not uncommon to see plumes of blue smoke from the locomotives exhausts.
Withdrawal.
The first withdrawals of the class occurred in May 1973 of numbers D1019 ‘Western Challenger’ and D1032 ‘Western Marksman’. Seven other members were withdrawn during 1973 including D1017 – 20, the only ‘Westerns’ not to be fitted with dual brakes. 1974 saw another 11 withdrawn, however 1975 witnessed 18 withdrawals, leaving 34 of the class to run into 1976 mainly due to Class 50 shortages. When the problems with the 50’s traction motors was rectified, 27 ‘Westerns’ were withdrawn during 1976 leaving numbers D1010 / 13 / 22 / 23 / 41 / 48 / 58 remaining at the start of 1977. D1022 and D1058 had gone in January leaving five survivors, although numbers D1013 ‘Western Ranger’ and D1023 ‘Western Fusilier’ performed the ‘Western Tribute’ tour on the 26th of February. These last five ‘Westerns’ were all withdrawn on the 28th of February 1977, the last of the Western Region diesel-hydraulics.
Preservation.
Seven ‘Westerns’ have been saved for preservation, five of which were still in BR service until 28th of February 1977. They are numbers :
D1010 ‘Western Campaigner’ although this engine masquerades as D1035 ‘Western Yeoman’,
D1013 ‘Western Ranger’,
D1015 ‘Western Champion’,
D1023 ‘Western Fusilier’,
D1041 ‘Western Prince’,
D1048 ‘Western Lady’, and
D1062 ‘Western Courier’
Specifications.
Wheel arrangement Co-Co Wheel diameter 3ft 7in
Weight 108 tonnes Height 12ft 117/8 in
Length 68ft Width 9ft
Minimum curve negotiable 4½ chains Maximum speed 90mph
Wheelbase 54ft 8in Heating type Steam – Spanner Mk III
Brake force 82 tonnes Tractive effort 72,600 lb (later 70,000 lb)
Total engine horsepower 2,700 hp Power at rail 2,350 hp
Fuel tank capacity 850 gallons Boiler water capacity 800 gallons
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The ‘Hymek’ class were unique by the fact that they were the only Type 3 diesel-hydraulics to be built as this design was not part of the Modernisation Plan for Britain’s railways. Beyer Peacock were hoping for a share of the diesel orders then being placed for Britain’s railways and were in fact building shunting locomotives plus 200 sets of underframes for the Brush Type 2 locomotives. With an intention of supplying complete locomotives for future orders, Beyer Peacock looked into the possibility of building main-line diesel-hydraulics, and although BR employed Type 2 D6300 class and Type 4 Warship class, no plans were announced for a Type 3 machine of 1501 to 1750 hp.
In response, Beyer Peacock formed a consortium in 1958 with Bristol Siddeley Engines and J. Stone of Deptford, named Beyer Peacock (Hymek) Limited. Their design for a Type 3 locomotive featured a 16-cylinder Maybach MD870 engine capable of 1,920 hp, coupled with the Mekydro K184U transmission. Construction was to based at Beyer Peacock’s Gorton works in Manchester.
In June 1959, the BTC ‘Hymek’ class number D7017 at Riverside yard, Exeterordered an initial batch of 45 ‘Hymeks’ at a cost of £80,000 each, but in July 1960, ten months before the first ‘Hymek’ entered traffic, the BTC ordered a further 50 locomotives, such was the confidence in the design. A final batch of 6 locomotives was ordered in December 1961.
The Maybach MD870 engine was basically a stretched version of the MD655 engine to be used in the ‘Western’ class, but with four intercoolers and two turbochargers. Power was reduced to 1,740 hp at 1500 rev/min to bring it in line with the Type 3 specification. Manufacture of the engine was to be at Bristol Siddeley’s engine plant at Ansty, near Coventry although the first 20 units contained a number of parts from Germany. Similarly, of the 116 sets of Mekydro transmissions, 91 were made by J. Stone with the remaining 25 built in Friedrichshafen.
The stretched-skin type of body construction so successfully used by the ‘Warship’ and ‘Western’ classes was not required for the ‘Hymeks’. With conventional construction and, of course, a single engine and transmission, an adhesion weight of 75 tons was perfectly satisfactory. In addition, the absence of special construction methods removed the need for training of Beyer Peacocks workforce as well as entering into a licencing agreement with the Germans. The main load-bearing members of the ‘Hymek’ underframes were longitudinal rolled steel joists to which lighter angle sections were added to form the body framing. The body panels themselves were made from lightweight sheets as they were non-loadbearing as shown by the use of fibreglass mouldings for the cab roof.
The bogie used on the ‘Hymeks’ was the tried and trusted Commonwealth design, to which, wheels of 45 inches diameter were fitted. This was an odd size for the Western Region as previous diesel-hydraulic locomotives used wheels of 39½ or 43 inches diameter .
The first ‘Hymek’, number D7000, was handed over to the Western Region on Maybach MD870 enginethe 16th May 1961 in a ceremony at Paddington station, almost two months ahead of schedule, however, the last ‘Hymek’ number D7100 was held up until February 1964, after problems at Gorton caused a delay in delivery for almost twelve months.
There were two main differences between the first and last members of the class in that D7000 to D7044 were fitted with the Stone-Vapor train heating boiler and brakes were of the Knorr straight air type together with Laycock-Knorr compressors. Numbers D7045 to D7100 used the Spanner Mk. IIIa train heating boiler and brakes and compressors were supplied by Westinghouse. The location of the air horns on the first three members, which was under the buffer beam, was moved to the cab roof on the remainder of the class and those first members had their horns repositioned to the cab roof also.
Livery on all members of the class when delivered was Brunswick Green with a light green band band running the full length of the locomotive at waist height. In addition, the window surrounds were painted white. The running numbers were an unusual feature of the class in that the cabside numbers where made from cast aluminium. The ‘Hymeks’ did not receive the "TOPS" style of numbering which would have been ‘Class 35’.
In Use.
The first problems to befall the class arrived at the end of 1961. The engine coolant temperatures were found to be too excessive in addition to the more serious problem of transmissions failing on starting. The Western Region was obviously concerned with this latter fault, and to isolate the cause, the class were split into two groups. The odd numbered locomotives up to number D7075 had the engine derated to 1,350 hp whereas the even numbered members up to number D7078 had the first gear locked out of use. After much investigation it was found that there was a weakness in the transmission control gear Two Maybach MD870 engines removed for servicenot changing gear at the preset engine speeds, which in turn caused them to overheat. A strengthened control gear was found to be sufficient and all of the ‘Hymeks’ reverted back to normal condition by the end of 1963.
The Maybach MD870 engine generally have good performance and reliability with occasional engines loosing coolant into the cylinders. By the 1970s, the engines regularly completed 8,000 to 10,000 hours service between overhauls. The Mekydro transmission, however, was prone to several faults including converter failure, damage to the clutches, stripped gear teeth and metal in the filters. The rate of failed transmissions got so bad that spare units were constantly in short supply and to keep some members of the class in service, transmissions had to be borrowed from other ‘Hymeks’. However, following a period when the ‘Hymeks’ were given relatively easy workloads and schedules, the class turned in probably the best performance of all the diesel-hydraulics.
The first ‘Hymeks’ to be withdrawn were numbers D7006 and D7081 in September 1971. A additional 78 members were withdrawn by the end of 1972 leaving just 21 examples, 14 at Old Oak Common and 7 at Bristol Bath Road to face a bleak future. However, by the end of 1973, ten survivors were still in service due to the ‘Hymeks’ replacement locomotive, the Brush Type 2 (Class 31), initially suffering twice the failure rate of the ‘Hymeks’.
British Railways organised a ‘Hymek Swansong’ tour on the 22nd of September 1973, hauled by D7001 and D7028. While the pair were waiting at Didcot, number D7026 ran through with an Oxford express as if to show that the class were far from finished. And so it turned out that way, as just four ‘Hymeks’ were withdrawn during 1974 leaving D7011/17/18/22/28 and 29 in service towards 1975. However the ‘Hymek’ survival could not last forever and in January 1975 D7028 was withdrawn, followed by D7029 in February and the last four in March.
Many people regretted the passing of the ‘Hymeks’ as they were probably the most reliable and successful of all the diesel-hydraulics. Their downfall was the lack of standardisation of parts with other locomotive classes together with the shortage of spare parts which led to the cannibalisation of the withdrawn examples to keep the few remaining locomotives in traffic, a situation not helped by the closure of Beyer Peacock in July 1966.
Preservation.
Four ‘Hymek’ locomotives escaped the cutter’s torch and they are numbers D7017, D7018 D7029 and D7076.
Specifications.
Wheel arrangement Bo-Bo Wheel diameter 3ft 9in
Weight 74 tonnes Height 12ft 10½ in
Length 51ft 8½in Width 8ft 8½in
Minimum curve negotiable 4 chains Maximum speed 90mph
Wheelbase 36ft Heating type D7000-44: Steam – Stone OK4616, D7045-100: Steam – Spanner Mk III
Brake force 33 tonnes Tractive effort 46,600 lb
Total engine horsepower 1,740 hp Power at rail n/a
Fuel tank capacity 800 gallons Boiler water capacity 800 gallons
