BR Automatic Train Control System (AWS)

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In 1948, the Railway Executive made a recommendation to the British Transport Commission to adopt, in principle, the application of a system of automatic train control. The term “Automatic Train Control,” although that was its official title, is probably somewhat misleading, since it does convey the idea of total automation and that, as we know today, is something entirely different, The ATC system subsequently adopted on British Railways provided for a visual and audible warning of the position of a distant signal, and where the latter was at caution, if the indication in the locomotive cab was not cancelled by the driver, an automatic brake application was made.

There were prior to 1948, two other ATC/AWS systems already in use, that on the GWR, introduced there in 1912, and a system, similar in many respects to the later BR standard type, installed by the LMSR on the LTS line in 1938. In keeping with the Railway Executive’s principle of standardising combinations of the best practices from other regions, experiments of various kinds were carried out between 1948 and 1952 on potential ATC/ AWS systems. On the face of it, only having two practical systems with which to effect comparisons, the task would seem to have been relatively straightforward. However it appears that a number of technical difficulties arose during this time, and then, if one is to believe the report of the inquiry into the disastrous Harrow & Wealdstone accident of October 1952, there was the question of snow and ice in the north. 1n point of fact it was the cause of this accident which both laid emphasis on the need for, and gave additional impetus to, the development of British Railways Standard ATC system.

BR ATC DiagramBR ATC Maintenance InstructionsThe prototype apparatus was installed during 1952 over the 43 miles between New Barnet and Huntingdon on the Eastern Region main line. The first locomotive to be equipped with the new ATC apparatus was the new Peppercorn Al Pacific no. 60150 Kestrel, which on 17 October 1952 took the 3.10 p.m. from Kings Cross on the first of a series of tests. The testing took some considerable time, for it was not until 1957 that the authorities were entirely happy with the system, and then declared it to be adopted for standard use on all regions of British Railways, the GWR system notwithwithstanding, although much of the latter was replaced by the BR standard system in later years. It has now been fitted to almost all traction units and extended to cover most of the important lines throughout the BR network; the title being altered to Automatic Warning System in order to give a more precise indication of the system’s function.

Operation of the system was based on the use of magnets situated in the permanent way between the running rails, with the tops of the magnets at rail level. The designed purpose of the system was to give the driver audible and visual indication of the position of a distant signal, 200 yards in advance of the signal. The two magnets were placed 2ft 6ins. apart, centre to centre, the one furthest away from the signal being permanent, the nearer being electrically activated when the distant signal was held in the clear position, and dead when at caution. If the indicators were overrun with the signal at caution and the driver had not cancelled the indication, an application of the brake would be made since the apparatus was connected to the automatic brake. There were a total of four indications of the position of a distant signal that could be given to the driver, two visual and two audible. The audible indications were given by a bell or a horn; the former ringing for two seconds on passing over the inductor of a distant signal at clear, and the horn was actuated after a delay of one second on passing over the inductor of a distant signal at caution. The two visual indications were provided by the Driver’s Control Unit (DCU). On passing over the permanent magnet of a signal at caution, the visual display would be changed from yellow and black to all black; then on passing over the electromagnet the horn would be sounded and an automatic brake application made after a delay of three seconds. Re-setting the equipment by the driver would return the display to a yellow and black aspect. If the signal being approached was off, or at clear, the same procedure would take over the perm- anent magnet although, since the electromagnet would in this case be energised, on passing it the DCU display would remain black and a bell would ring for two seconds. In point of fact the DCU would display a black indication until a distant signal set at caution was approached, following which, operation of the re- setting device would change the display to yellow and black.

BR ATC fitted 78036 - Photo 692 copy

BR Standard Class 2MT 2-6-0 in this view, shows the battery box on the running boards, immediately in front of the cab spectacle plate. Photo courtesy: Lens of Sutton

Locomotive Equipment.

The apparatus provided on the track was basically very simple, consisting essentially of the two inductors. Locomotive equipment however amounted to a total of some ten separate items and associated cabling and pipework. Since it was intended for use on steam locomotives, the apparatus had to be specially designed to withstand the extreme conditions to be met with: smoke, steam, heat, vibration, shock etc. The equipment was further designed about two basic parameters:-

  1. From one shopping to the next, all items should function without maintenance from the shed staff.
  2. Should one item fail, it could be replaced without requiring any disturbance to the electrical wiring.

The sensing device, or receiver, was mounted on a stretcher immediately in front of the leading coupled wheels and positioned centrally between the frames at a height above rail level of about 4 Y, and 6 Y, inches. The height of the receiver was not over critical, hence the allowable range of movement of two inches although once fixed no provision was made for adjustment. The receiver was basically a polarised relay, actuated by the track mounted inductors, to transmit electric current to the Relay & Cab Junction Box. This was effected through its own junction box mounted on the frame, to which it was attached through a flexible connection. Flexible connections were provided between the receiver junction box, receiver and relay unit, to allow for any relative movement between the engine frame and receiver. The relay and cab junction box, or relay unit, could be described as the nerve centre of the apparatus, to which all cables from the other items of equipment were connected, its function being to translate the electrical information into audible and visual indications of the signals and where appropriate to initiate the application of the brake. Perhaps the second most important item was the Driver’s Control Unit (DCU) on this unit, the signals being displayed to the driver visually. The unit, mounted in the cab on the driver’s side contained an electro-pneumatically operated solenoid valve, indicator and resetting handle. The solenoid valve, being connected to both electrical and pneumatic circuits and when not activated, under normal conditions ensured that the feed to the horn was maintained at normal air pressure with the brakes off, via the timing and ATC reservoirs. The last key item of equipment on the engine was the ATC Brake Valve, through which the actual automatic application of brake was made. The Brake Valve consisted of a diaphragm acting on a flat disc whose centre was attached to a spindle operating the main brake valve. The valve was normally closed to atmosphere, one side being attached to the train pipe and the other to the Timing Reservoir. Application of the brake was made by admitting air at a controlled rate through the Timing Reservoir, lifting the diaphragm and opening the valve to admit air to the train pipe. A plug on the valve, which would normally be sealed in the open position, could be screwed down to close it in the event of a failure. The remaining items of equipment could probably be classed as ancillary, except perhaps for the ATC Vacuum Reservoir, whose function was to maintain vacuum in the Timing Reservoir and to equalise pressure between train pipe and ATC side of the brake valve.

BR ATC fitted 70033 - Photo 917 copy

BR Standard Class 7MT Britannia Pacific No. 7033 “Charles Dickens” in original guise, with handrails around the smoke deflectors, also shows the battery box on the running boards, immediately in front of the cab spectacle plate. Photo courtesy: Lens of Sutton

On the whole, it is not necessary to describe all the individual items of the Standard AWS apparatus at this stage, since it is the broader principles of the operation of such devices that concerns the majority of us. In retrospect it is interesting to note that much of the equipment, including the specialised electrical devices, was perhaps crude and bulky when compared with equipment of today.

As previously indicated, it was not until 1957 that British Railways decided to adopt as standard the form of AWS described here and eventually extended to cover most important lines on the system. It was intended to fit all traction units with the equipment. Though this has largely been accomplished, quite a number still remain in service unfitted. The GWR’s original electro- mechanical method of AWS has also now succumbed to the standard arrangement, removing the last traces of individuality of that region. Doubtless though it will not be long before the Standard AWS is superseded by a more sophisticated arrangement further to improve signalling and train control.

References.


  1. BR London Midland Region Magazine – November 1952.
  2. BR Automatic Train Control: Maintenance Instructions [BR 31168/2).
  3. BTC Handbook For Steam Locomotive Enginemen.
  4. See also: Kempe’s Engineers’ Yearbook Vol. 1.

 

-oOo-

Towards Nationalisation

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The ‘Big Four’ railway companies had all been under state control during the Second World War, and largely expected to return to private ownership and pre-war operation and management from 1945. However, the political landscape changed radically with a Labour Government in office, and the cultural and social impact of the war had dramatically affected the mood of everyone.

Although it had been something of a struggle, from Herbert Morrison’s early speeches in late 1945 to Parliament to outline how the process would bring all inland transport within public ownership.

An interesting comment made by him in November 1945 is worth recalling:

“It is the intention of the Government to introduce, during the life of the present Parliament, Measures designed to bring transport services, essential to the economic well-being of the nation, under public ownership and control.”

Unsurprisingly, the Government’s official opposition were obviously against the idea, and supported the ‘Big Four’ railway companies campaign against nationalisation. In parliament they were accused of obstructing and delaying tactics to try and prevent its passage. One commentator suggesting that if the Government did not use parliamentary procedures to limit the time for debate, it would be years and not months before any progress could be made.

Given the economic state of Britain in the late 1940s, this would be very damaging to post-war recovery.

The LMS and the other companies were actively campaigning against nationalisation, and in March 1946, amongst many other questions in Parliament, there were questions about how the then subsidies paid to the LMS would be prevented from campaigning against state ownership.

HC Deb 12 March 1946 vol 420 c202W

H. Hynd asked the Minister of War Transport whether he is taking steps to ensure that the L.M.S. Railway Company’s campaign against the Government’s nationalisation policy will not be financed from profits that would otherwise accrue to the State under the Railway Control Agreement.

Barnes Expenditure incurred by the railway companies for the purpose in question would be charged to their own funds and would not fall upon the Control Account.

The companies had all contributed to a document – which might be called both a publicity booklet – and, the start of that campaign. This is what it said in its introduction:

In their conclusion at the end of the booklet describing how well they’ve achieved efficiencies and continued to operate services during wartime they stated:

Conclusion

Clearly, the ‘Big Four’ believed they would be best placed to take the business forward, despite the massively damaged economy, ongoing rationing, general economic stagnation, and shortage of all kinds of materials, products and most importantly, shortage of people.

In December 1946, as the Transport Bill was being given its second reading, the government position was exemplified in an interesting comment made by Mr Strauss the Transport Minister’s right hand man:

“…. suggest that we are, in this Measure, adopting the only solution that is capable of resolving the deep economic conflict within this industry.”

The Transport Act 1947 received the “Royal Assent” on 6th August 1947, and on 30th December 1947, the Manchester Guardian’s carried this interesting reflection from its “Special Correspondent”:  State Ownership of Railways

The aim was clearly for an integrated transport system, a view reinforced by a prominent “railway MP” and former railwayman – Walter Monslow – the MP for Barrow-in-Furness. Writing in the ASLE&F magazine “Locomotive Journal” in February 1947 he quoted the English philosopher John Stuart Mill:

“Countries which, at a given moment are not masters of their own transport, will be condemned to ruin in the economic struggles of the future.”

Loco Journal Cover - Feb 1947

Walter Monslow Article - Feb 1947 ASLE&F

Since 1948, the development of Britain’s rail network has undergone many changes, many technological, and quite a few operational and economic, but the goal of an integrated system has never been achieved. If anything since 1991, the country has seen ‘disintegration’ of transport, and with a private operator having to balance its public service, with responsibilities to shareholders, had the ‘Big Four’ taken over again in 1948, it is doubtful if progress would have been made easily.

Now that we have seen the impact of a return to private operations, and the lack of integration across transport, both within and beyond rail operations, I wonder what John Stuart Mill – once described as “the most influential English-speaking philosopher of the 19th century” would have to say about that in the 21st Century.

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Electro-Diesels are Back

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No – I know this is not the same!  But any opportunity to highlight the centenary of the formation of the UK’s own English Electric Co. seems OK.

The new Hitachi built Bi-Mode trains for Trans Pennine Express are a lot more sophisticated than the English Electric built electro-diesels for BR’s Southern Region in the 1960s, but the principle is the same – isn’t it?  Taking power from an external electrified contact system and having on-board diesel engines when on non-electrified lines.

Here’s what we had in BR days:

In November 1964, an item appeared in the “Locomotive Journal” from ASLE&F, and in describing the Bournemouth Electrification project, this little snippet appeared:

ASLEF Journal Extract 1964

Preston’s English Electric Co. had received an order for 43 of these locomotives, which was in essence part of the plan to elimiate steam traction, as well as following the Bournemouth electrification scheme.

They were numbered E6007-49 by BR, and designated Type JB to distinguish them from the six prototype Type JA locomotives, Nos. E600l-6, which later became class 71.  The new English Electric/Vulcan Foundry built locos became classes 73/1 and 73/2.  English Electric had supplied the power equipment for the six Type JA, BR built locos, which were constructed at Eastleigh Works, and entered service between February and December 1962.

The next batch, Type JB, were built at English Electric Co’s works at Newton-Le-Willows – originally the Vulcan Foundry – and delivered between October 1965 and January 1967.  The diesel engines were also manufactured at Vulcan Foundry, with the electrical equipment produced at the Preston works.

Class 73:2 Electro-Diesel

EE Class 73:2 No 6021

Class 73/2 No. E6021, and one of the few that never carried a name, on a typical transfer freight duty.      Photo: RPB Collection

Here’s what Hitachi have delivered:

The first of the “Nova 1” (class 802) trains arrived at Southampton on the 11th June 2018, and was successfully tested between Darlington and Doncaster in a 5-car set this month (July).  Further testing is planned for the TPE route in the North of England and Scotland over the coming months.  Also appearing in July 2018 are the new Hitachi Class 385 trains for the Glasgow Queen Street-Edinburgh Waverley route via Falkirk High. More class 385 trains  will be phased in over the coming months, before being extended to other routes across the Central Belt.

The new Class 802s for TPE are essentially closely similar to the same type delivered by Hitachi to Great Western, and for TPE are fitted with MTU/Rolls-Royce Series 1600 MTU PowerPacks.  The core of the PowerPack is the MTU 12V 1600 R80L, a 12-cylinder diesel engine, with low consumption/emissions, and meets the EU Stage IIIB emission legislation.

The trains, ordered as 19 x 5-car sets will be able to run in either five or ten carriage formation, capable of speeds of up to 140mph in electric mode and 125 mph using diesel engines.

Hitachi Class 802 at Doncaster Depot

Hitachi Class 802 for Transpennine Express at Hitachi’s Doncaster depot.

Further reading:

Transpennine Express “Nova 1” Begins Tests

Hitachi Class 385 Electrics

One issue that has not been addressed for the UK so far as the bi-mode trains are concerned, is whether this is a stop-gap solution pending the restart of electrification projects across the Pennines.

Nevertheless the new rolling stock looks like a welcome improvement.   This is a long way from the designs and requirements for rail operations in the 1960s, with fixed formation train sets – multiple units – and certainly more aerodynamic styling.

Let’s hope they can also be used on Northern Rail territory and lines in North West England.

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British Railways: Interchange Trials 1948

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Whilst it is the anniversary this year of the end of steam on BR, in 1968, just 20 years earlier, a series of comparative trials took place across the country, to analyses what was then the best in steam traction design, construction and operation.  Not surprisingly, these trials – which took place between April and August 1948, were latched on to by enthusiasts – as a form of competition to see which railway had the best steam types.

City of Glasgow on 1st Caledonian 17th June 1957

A classic shot of a classic pacific – although 46236 “City of Bradford” was used in the 1948 trials. Seen here is sister loco 46242 “City of Glasgow” on the inaugural run of The Caledonian in June 1957.                                                                                                                                                                    Photo: RPB Collection

RPB 220_Lens of Sutton

‘A4’ Class No. 60004 “William Whitelaw” at York on an enthusiasts’ special in the 1960s. As an express passenger type, it was natural to choose one of Gresley’s A4s, but 60022 “Mallard” did not acquit herself well, and was substituted by 60033/34 for the Interchanges.                                      Photo Courtesy: Lens of Sutton

70 years ago, a series of trials took place on the newly nationalised British railway network, to contrast and compare the best elements of the locomotive engineering design, and practice used by railways across Britain. Well, at least that was the plan.

The trials led, eventually to the new BR Standard steam locomotives, and covered espress passenger, mixed traffic and freight types, including a selection of some of the latest designs, WD ‘Austerity’ types, and some traditional designs.  The process was not particularly controversial, but new steam locomotives in the 1950s – especially as diesel and electric traction had already been established, and was developing rapidly.

Stanier 8F nearing Dalton in 2008

The LMS built this 2-8-0 in huge numbers – with over 600 in service by 1948. Many having been built by the other main line railway companies, Beyer Peacock and North British Loco. for war service at home and overseas. A natural choice perhaps for the 1948 trials.                                    Photo: RPB Collection

It may be that one of the main drivers was the ease of availability of coal as a fuel,where oil had to be imported, and the cost of electric traction’s infrastructure was expensive in the post-war economy of the UK.

Further reading

Clicking on the image below will take you to a more detailed discussion of the trials:

Interchange Trials - cover

Useful Links:

National Archive – Report of the Locomotive Testing Committee

RM Web – The 1948 Locomotive Exchange Trials – Discussions

1948 Locomotive Exchange Trials

BR’s First Year (The Spectator)

Loco Interchange Trials 1948 (Rly Mag)