Gloucestershire Transport History welcomes Michael Davie’s new falconry display website to the Gloucestershire Portal with a look back at 60 years of some remarkable "birds of prey" on rails.

10800 HAWK

10800 - later known as Hawk by Brush of Loughborough

In 1945 the London Midland & Scottish Railway (LMSR) Chief Mechanical Engineer H.G. Ivatt decided to produce a basic design for an 827 bhp diesel-electric locomotive for comparison with his slightly less powerful Class 2 2-6-0 and 2-6-2T and slightly more powerful Class 4 4-6-0 steam engines on secondary and branch lines.

In 1946 the LMSR placed an order with the North British Locomotive Co (NBL) of Glasgow to produce a locomotive to their specification. The design adopted was like an elongated shunter, mounted on two four wheeled carriage type bogies - each carrying two nose suspended traction motors - with the cab slightly set in from one end. The power unit used was a centrally-mounted 16 cylinder Davey Paxman 16RPH engine which drove British Thomson-Houston (BTH) electrical equipment located just behind the cab in the long hood section, which also housed a radiator group with side grilles and a roof fan. A ladder on the side of the short nose gave access to the filler cap of the 300 gallon tank of the Clarkson train heating boiler. The Clarkson device however soon proved unreliable and was replaced by a Clayton boiler. The cab arrangement enabled the driver to face the direction of travel using duplicate controls.

The loco was constructed just after Nationalisation in 1948-50 and when completed carried the British Railways number 10800 ( as opposed to the envisaged LMS number 800 ) beneath the diamond shaped NBL worksplate. The livery was standard black with silver bogies and - prior to press demonstrations - a silver hood roof. After release from North British No.10800 underwent testing in Scotland. After a few months the loco was allocated to British Railways London Midland Region (LMR) at Willesden and operated tests in the London area.

In March 1952 it was reallocated to Brighton from where it operated on the Victoria-Oxted line and various Central and South Eastern routes such as those between Victoria and London Bridge to East Grinstead and Tunbridge Wells to assess branch line operation. The Southern sojourn of 10800 ended in early 1955 when it was reallocated to Plaistow shed on Eastern Region for further testing, eventually being returned to the LMR and deployed from Rugby shed on such workings as Birmingham-Norwich line before being withdrawn from service in August 1959. By this time a small class of very similar Bo-Bo single cab locomotives built by NBL were being introduced as part of British Railway’s 1955 Modernisation Plan. However, these Class 16s - and the very similar Class 15s produced by British Thomson-Houston - were to have careers of only a decade as branch and secondary lines were felled by the infamous Beeching Axe.

After withdrawal 10800 was taken to Doncaster Works where it lay for many months awaiting a decision on its future. In 1962 however Brush of Loughborough bought the Bo-Bo machine for research into commutatorless traction motors. Brush replaced the original Paxman engine with a 1400 bhp Bristol Siddeley Maybach MD655, which turned a Brush 3-phase brushless alternating current (ac) generator. The generator output was then passed through sophisticated electronics before powering ac traction equipment. In the tradition of Brush experimental locomotives it was named, although no "Hawk" plates were ever carried or even cast. It was numbered 710 on the Brush construction list

After modification at Brush, Hawk was put through a test programme for most of 1963-64, prior to receiving major body attention and repainting into a green and grey livery. In early 1965 the loco was inspected by BR and transferred to the Rugby Testing Station for performance tests. After further static trials Hawk was accepted back onto BR tracks for active operation over the former Great Central Leicester-Nottingham route. Although basically successful it suffered a number of technical problems, and by 1968 Brush decided not to continue with the project. Hawk was stored at Loughborough before being finally broken up in 1972-73. During the 1972 Miner's Strike the engine and generator were cannibalised to provide emergency power for the Loughborough works.

D0280 / 1200 FALCON

D0280 Falcon newly outshopped by Brush at Finsbury Park on 13 October 1961

Project 'Falcon' - or Brush contract No. 280 – had commenced in April 1959, just before the acquisition of "Hawk". Contract 280 called for the design and construction of a prototype second generation main line diesel electric locomotive that would offer both more power for less weight than the existing 2 000 bhp English Electric Class 40 in British Railway’s Type Four ( 2000 bhp - 2750 bhp ) power band.

As no suitable single prime mover of the required output was available it was decided that Falcon would incorporate two smaller units UK built Bristol-Siddeley Maybach engines each rated at 1440 bhp and coupled to a Brush 915kW main generators, providing power to six Brush traction motors. The sides of the stressed skin body - housing two high speed power units and generator groups - featured grilles that were almost the same on both sides while the cabs represented an evolution of the 1957 vintage Brush Type 2 ( later Class 31) design by consultants Wilkes and Ashmore. The 2 800 bhp locomotive was fitted originally with vacuum brakes and steam heating.

Construction of Falcon started in December 1960 and was finished in September 1961 when the lime green and chestnut brown machine, carrying the number D 0280 and a Falcon transfer nameplate, emerged from the Brush works in Loughborough. Not only was the first zero of the number a reflection of the original contract designation but it avoided confusion with existing Class 40 locomotive D280.

After release the loco was subject of a detailed BR inspection before entering traffic on the Eastern and London Midland Regions. During its time on Eastern Region, Falcon was kept at Finsbury Park depot alongside the then new fleet of English Electric "Deltics" - another high performance type with fast-running engines.

On a number of occasions in the first few months the loco was returned to Brush for modifications. At the end of 1961 the loco was transferred to the Western Region from where it worked a number of controlled road tests to evaluate power unit performance.

One of the cast aluminium nameplates on D0280 Falcon

In March 1962 Falcon was again returned to Brush for equipment upgrade and was fitted with cast alloy Falcon nameplates. D0280 returned to BR in April 1963 and was shedded at Sheffield Darnall, from where it operated services such as the 'Sheffield Pullman' and a selection of heavy freight diagrams. The Sheffield testing continued until November 1963 when the loco was again returned to Brush. A classified overhaul in late 1964 was followed by a period of testing based at Stratford depot on Eastern Region.

By this time however, both Brush and BR Crewe works were building large numbers of 2750 bhp Class 47 Co-Co diesel electrics. Although sharing many stylistic features with "Falcon" these locomotives were fitted with a single slower running Sulzer powerplant as by the time of their introduction in October 1962 British Railways policy - influenced by the new Chief Mechanical and Electrical Engineer J.F. Harrison - had turned against high speed engines. It was to turn back to them again in 1968 however with the introduction of the High Speed Train multiple unit concept. Prior to the decision to order a large quantity of Class 47s though, BR had given serious thought to building a diesel electric version of the Class 52 "Western" at Crewe which would have occupied the pre-TOPS numbers D1200-1258.

After an idle 12 months meanwhile, D0280 was formally returned to BR in January 1965 for active service, but by now painted in BR Brunswick green livery with small yellow warning panels. From that point Falcon came under a special contract between BR and Brush, whereby the machine would be operated and maintained by BR, but any major repairs would be referred to Brush.

After an idle 12 months meanwhile, D0280 was formally returned to BR in January 1965 for active service, but by now painted in BR Brunswick green livery with small yellow warning panels. From that point Falcon came under a special contract between BR and Brush, whereby the machine would be operated and maintained by BR, but any major repairs would be referred to Brush.

Once on BR, Falcon was allocated to Bristol Bath Road and used alongside the 'Western' diesel-hydraulic fleet ( powered by similar Bristol Siddeley Maybach engines) on Paddington-Bristol line services. This operating arrangement continued until 1970 when BR approached Brush to purchase the loco at its scrap value. This was eventually agreed, but with the unusual proviso in the contract that, once its operating life was over, it had to be sold for scrap and not preservation. This was because Brush believed that only it should profit from their prototype.

This arrangement was accepted and in January 1971 the loco entered BREL Swindon works for a major overhaul, emerging in February painted in standard BR blue with full yellow ends and carrying the BR Number D1200. Under the then new BR Total Operations Processing System (TOPS) the unique locomotive was identified as Class 53.

Falcon was again allocated to Bristol Bath Road, being subsequently transferred to Newport Ebbw Junction, where it was used on Llanwern steelworks iron-ore duties.

However,in late May/ early June 1974 Falcon made a sudden, and unexpected appearance at Loughborough Midland station - the first time it had been back there since early 1965. This surprised the station manager who didn't have a clue what he was supposed to do with it; and even more surprised were Brush themselves - who didn't know what they were supposed to do with it either! Transferring the machine into the works was not an available option as the entry tracks had been lifted some years earlier, so Falcon lay in the station sidings for a few days whilst the matter was sorted out, during which time rumours on its future became rife.

In the wake of the power crisis that plagued Britain during the winter of 1973-74, British Rail had devised a cunning plan to sell Falcon back to Brush for use as an emergency generator; however, it appears that nobody in BR had thought to consult Brush on the matter! Once the error had been realised (and Brush, presumably, had declined BR's kind offer!) Falcon returned to freight duties in South Wales.

Due to its non-standard equipment – notably a lack of electric train heating - D1200 was withdrawn from 5 October 1975 and sold to Cashmores of Newport who broke the locomotive up in March 1976.


HS4000 newly finished at Brush of Loughborough

Laid down at the Loughborough works of Brush Traction in 1966 (Brush Works number 711 of 1967) and completed in late 1967 HS4000 'Kestrel' was a private venture, designed and built by Brush Electrical Engineering Co Ltd, Loughborough ( by then a division of Hawker Siddeley ) in conjunction with Sulzer Bros Ltd of Winterthur, Switzerland. It was also the world's most powerful Sulzer engined diesel locomotive and had been inspired by an outline specification produced by British Railways in 1964/5 for a Type 5 ( 3 000 bhp plus ) Co-Co locomotive suitable for both heavy freight and express passenger work. It was also specified that the new machine would weigh less than 126 tons in working order.

The locomotive was an attempt to install 4,000hp into a single locomotive using the latest ac technology – much of which had been pioneered on 10800 Hawk after its acquisition by Brush. Cost savings were hoped for over both existing twin-engined locomotives (such as BR's Swindon and Crewe built diesel hydraulic Class 52 "Westerns" the English Electric Class 55 "Deltics" and of course Brush's own Falcon) and the American railroad approach of multiple locomotive lash-ups.

Rather than an uprated version of the 12 cylinder Sulzer 12LDA28 found in over seven hundred British Railways locomotives, the new Winterthur built 16LVA24 prime mover had sixteen cylinders arranged in two V shaped banks delivering 4,000 bhp at 1,100rpm. This was coupled to a Brush alternator/exciter and combined train heat/auxiliary generator. A smaller dynastart unit was also incorporated to turn over the engine for starting and provide direct current power for battery charging, engine priming pumps, exhausters & compressors.

The main alternator was a ten pole three phase salient pole machine with brushless exciter supplying power for the six traction motors. The alternating current output was rectified in a bank of eighty four silicon-diode three phase bridge connected rectifiers. With the engine running at 1,100rpm the ac/dc power system would supply a continuous output of 3,110 amp, 810 volts, 2,520kW or 4,980 amps, 504 volts, 2,510kW according to the loading. The combined train heat/auxiliary alternator, with brushless exciter incorporated three 3 phase stator windings which supplied the power through rectifiers for the train heating. One of the windings also supplied the power for the auxiliary machines. Output was 533kVA, 680 volts ac at full engine speed.

The exciters for the main alternator and the train heating/auxiliary alternators were of the rotating armature, brushless type, the output being rectified by silicon diodes mounted on an extension of the rotor shaft. Each exciter was secured to its alternator by attachment of the magnet frame to the alternator end frame, the rotor windings in each case being mounted on the extended alternator shaft.

The six traction motors were dc operated four pole series wound machines, force ventilated with 3,000 cubic feet of air per minute, each rated at 515hp, 504 volts, 830 amps at 681rpm, or 509hp, 464 volts, 900 amps at 610 rpm. Each motor was mounted on a suspension tube concentric with the axle it drove and flexibly attached to the bogie frame via a bracket attached to the motor casing. Drive was transmitted to the axle through a spur-type reduction gearing enclosed in an oil bath gear case, the driven gearwheel incorporated bonded rubber units to give torsional resilience to damp out vibration in the drive. The gear ratio chosen would permit a continuous speed of 110mph.

Three phase squirrel cage type machines ac powered from the auxiliary generator powered the radiator cooling fans and the traction motor blowers. DC operated motors powered the compressors, exhausters, priming pumps and the blowers for cooling the dynamic brake resistors.

The braking system was mechanically of conventional design, the operating systems included vacuum, straight air, automatic air and dynamic with hydraulically operated hand & parking brake. Two exhausters & compressors provided air or vacuum for the braking systems. The dynamic braking system was integrated with the air brake system, the former having precedence. Speed was the controlling factor between the operation of the two systems, sensing devices determine the point at which the braking load was transferred between the two systems - the dynamic brake becoming less effective as speed decreased.

Three small racks with detachable modules incorporating plug-in printed circuit boards formed the core of the solid-state control system. Sensing elements (transducers) provided the control system with a variety of readings, from which appropriate action was selected. External sockets allowed for diagnostic fault finding or monitoring during normal operation. Those operations controlled electronically were: load regulation, traction motor field divert, dynamic braking, wheelslip, engine temperature, train heating, overload protection, automatic voltage regulation of the ac & dc circuits.

The body - like the many Class 47's produced at Loughborough - had a stressed skin without conventional underframe or chassis and the cabs received a stylish streamlined treatment by Wilkes and Ashmore. The original single piece cast bogie frames with coil and beam suspension were also unusual in having an unequal wheelbase - the outermost wheels being 7'3" from the central axle while the inboard wheels were 7'8" away.

In express passenger mode Kestrel's 4 000 installed bhp could have propelled it and a sizeable train to 125 mph and with a driving carriage at the opposite end of its rake it would have made an interesting comparison with the Class 91 ac electric and Mark 4 carriage combination of 20 years later. However, with the advent of the High Speed Train concept in 1968 the golden era of powerful the mixed traffic diesel locomotive on British Railways was over.

Worse still, in January 1968 BR's Derby Works discovered that Kestrel weighed 133 tons, considerably over BR's desired 20 ton per axle limit. Part of the reason for its excessive weight however was due to it carrying a considerable amount of prototype equipment. Despite this, HS 4000 was to prove its mettle on some spectacularly heavy freight trains.

From Derby 'Kestrel' visited Marylebone on 29 January 1968 for the official handing over ceremony. Initial trials were on the northern yet-to-be electrified portion of the West Coast Main Line with Shap being used as a test of the locomotive's capabilities. This included taking twenty four coaches (660 tons) over Shap with 46 mph being noted at the summit. In the middle of May 'Kestrel' was allocated to Tinsley depot (41A) and put through its paces on the many coal workings out of Shirebrook, particularly to Whitemoor, handling two round trips a day, five days a week with coal trains loaded to a maximum of 1600 tons. These workings were:

7J31 SX 11.09 Mansfield Colliery Sidings - Whitemoor (due 14.20)
7P31 SX 15.10 Whitemoor (Norwood Yard) - Mansfield Colliery Sidings.
7J07 SX 19.40 Mansfield Colliery Sidings - Whitemoor (due 22.53)
5P07 SX 23.45 Whitemoor (Down Yard) - Thoresby Colliery Jct.

By mid August 14,000 miles had been covered, with an availability of 88%. At this time it also visited Darlington Bank Top for bogie rotational tests. In August tests on the Mansfield - Lincoln line with coal hopper wagons totalling 2,028 tons were successfully completed under a variety of weather conditions.

In August and September mobile tests were carried out over the Derby-Crewe-Nuneaton-Derby route to test a number of the innovative features of this machine. Dynamometer Car M45049 and Mobile Test Unit No 3 M45055 were used, additionally a dead Class 86 (E3132) was added to the formation when operating between Crewe & Nuneaton. Kestrel was noted in the Research Dept yard on 24 August and worked over the Crewe - Nuneaton - Leicester route on 27/28/29 August. After this it returned to the coal duties out of Shirebrook, on the Mansfield - Whitemoor route. By the end of 1968 engine hours had reached 1,731 and total mileage was about 26,000.

During the same period in 1968 HS4000 was involved in a variety of tests over the Derby-Stoke-Crewe-Nuneaton-Derby route. The load consisted of electrically braked mobile test units in conjunction with the rheostatic braking supplied by Class 86 E3122. The highest speed attained was 102mph, though the tests concentrated on performance expected under BR's normal daily running conditions. However, on 31 August 1968, Kestrel took a break from its test runs to visit the Derby Works Open Day.

HS 4000 on show at Cricklewood Open Day on 12 July 1969

In May/June 1969 Loughborough fitted Class 47 bogies to 'Kestrel' to bring its overall weight down and allow its use on higher speed passenger workings. Because the traction motors in the Class 47 bogies were smaller, the locomotive's continuous rating was reduced. These working were initially manned by Shirebrook crews and inspectors but later Finsbury Park crews trained on the locomotive allowing a more intensive use commencing October with trips between Kings Cross and Newcastle. However, HS4000 did take time off to appear at Cricklewood Open Day, 12 July 1969.

On 30 July 1969 Kestrel worked a late morning test train of six coaches from Doncaster to Peterborough and return. Shirebrook crews with a Doncaster pilot manned the locomotive, reaching Doncaster via Tuxford West curve. On 18 October HS4000 and six coaches were noted on a special at Kings Cross, the locomotive later moving off to Finsbury Park. Regular diagrammed working commenced on 25 October with the 1N08 09.00 Kings Cross - Newcastle and return 1A30. By 27 October it had shifted to the 1N06 07.55 Kings Cross - Newcastle and 1A32 return.

HS4000 was noted at Stratford depot on St Patrick's Day 1970, laying over whilst handling the Hull - Stratford freightliner. Maintenance for 'Kestrel' during this period was undertaken by Tinsley, being noted there on 5 April 1970. The dark chocolate and cream liveried locomotive visited Crewe Electric Depot on 19 April 1970 as one of the star attractions for the depot's Open Day.

On 29 May 1970 English Electric Class 20 B0-Bo 8313 ( later 20 213) hauled Kestrel from Tinsley to the Vickers Works at Barrow. It set out using the Calder Valley route, Hall Royds Junction, and Copy Pit. After arriving at Rose Grove the LMR refused passage of the duo, with them retreating over the route just travelled. However by the next day Barrow had been reached and Kestrel would remain at Vickers until early September.

After return from the Vickers works HS4000 went back to work on the Mansfield - Whitemoor mineral trains.

In June 1971 the locomotive visited the Vickers Armstrong works at Barrow for engine removal and overhaul. Upon release from Vickers it returned to Shirebrook for more Mansfield - Whitemoor freight workings.

Its continued stay on BR was brief for the locomotive was sold to the USSR railways. After attention at Crewe Works, it was removed to Cardiff Docks and shipped to Leningrad ( now St Petersburg ) on July 8th 1971.

During 1971 an international exhibition 'Railroad Rolling Stock-71' was held in Scherbinka. Presumably HS4000 was present for this. It would be tested at Scherbinka and no doubt some of the results filtered into Soviet locomotive designs. More immediately, and perhaps most noticeably though, the need for a Type 5 freight Co-Co was met by the Brush Class 56 design built in both Britain and Romania from 1976.

At some point the power unit was removed from Kestrel and set up in a workshop to allow further tests, of a static nature, to be carried out. The locomotive shell remained intact and was ballasted with concrete, presumably for use as a dead-load vehicle. By the early 1980's it is reported that the locomotive body was suffering severely from corrosion and - apparently as late as 1993 - Kestrel was dismantled for study by engineering students and then scrapped.


At some point the power unit was removed from Kestrel and set up in a workshop to allow further tests, of a static nature, to be carried out. The locomotive shell remained intact and was ballasted with concrete, presumably for use as a dead-load vehicle. By the early 1980's it is reported that the locomotive body was suffering severely from corrosion and - apparently as late as 1993 - Kestrel was dismantled for study by engineering students and then scrapped