Uncircling The Circle: part 1


In part 2 of The Past, Present and Future of Metropolitan Line Services we finished with details of frequencies for the Metropolitan Line once the Sub-Surface Lines upgrade was complete. With plans for a overview of the ultimately intended service pattern for all the Sub-Surface Lines in mind, we now look at the Circle Line.

Never Run Your Trains In A Circle!

In the 1960s and 1970s London Transport had a flourishing international consultancy arm which made money by advising other cities on on how to go about setting up and running a metro service with a particular emphasis on advising far eastern countries how to plan their fledging metros. Rumour has it their first bit of advice was always: Never, ever run your trains in a circle!

Given that London Transport knew that running trains in a circle was a seriously bad idea it begs the obvious question of why on earth didn’t it follow its own very sensible advice. With that in mind, in part 1 we look at the 19th and 20th century history of the Circle Line with an emphasis on the nature of its operation.

The Circle Line was created – reluctantly


Mansion House station in 1896 when the Circle Line had already been completed.Note the reference to “Circle Train” and not “Inner Circle”.

In 2013 one hardly needs reminding that the Metropolitan Railway opened as far as Farringdon in 1863. On the south side of today’s Circle Line its bitter rival, the District Railway, had opened as far as the woefully misnamed Mansion House station, where it had a four platform terminus, as early as 1871. The station was located at the junction of Cannon Street and the fairly recently-built Queen Victoria Street. This was not the originally intended location for this station. It should not be hard to guess where that was.

It is difficult to imagine nowadays in the gloom of the current day Mansion House station that for thirteen years this station would have been a busy London terminus complete with short sidings on the western side to assist with locomotive changes. Although it originally had four platforms it only had three tracks into them (rather like current day Uxbridge and Cockfosters) although a fourth track was added later in its life and the platform layout changed.

Meanwhile the Metropolitan Railway too was pushing eastward. Moorgate, long planned, was reached in 1865 just two years after the original opening as far as a temporary station at Farringdon. Like Mansion House station, the multiple platforms suggest that the Metropolitan, having reached the city, was in no hurry to continue eastwards beyond Moorgate. Indeed, land and costs generally would start to get really expensive. It took a further 10 years to continue the short distance to Liverpool Street and a yet another additional year to get to Aldgate, the next station beyond Liverpool Street – again a station built with four platforms and giving the impression that it was intended to be the end of the line.

If it had been up to the two rivals things might have remained this way. A joint service from Mansion House to Aldgate was run and although it was referred to as the “Inner Circle” it was in fact more like a horseshoe. It was called “Inner” because at various times there was also a “Middle” and an “Outer” Circle service. Confusingly, when reading about Circle Line history, “Inner” and “Outer” were many years later used to refer by staff to anti-clockwise and clockwise services on the “Circle Line”. By then the other services no longer existed so there was no confusion amongst themselves as to what service was meant.

The two rival companies could have probably seen that completing the circle was going to be expensive hard work which was probably very convenient for passengers but not something that was going to bring in much additional revenue. The also probably did not want to progress with something that would extend the need for a high-degree of day-to-day co-operation. They may have even appreciated the difficulties that running such a service would cause.

The two companies may not have wanted a Circle Line but parliamentary committees in both 1863 and 1864 came out strongly in favour of the idea. Indeed, the success of getting bills through parliament to further the Metropolitan and District’s aspirations below highly contentious land in central London was probably possible in no small measure to parliament’s dream of seeing the circle completed.

When the two companies seemed unwilling to progress further a third independent company, the Inner Circle Completion Company, attempted to do the job instead. The stick to get the two unruly siblings to co-operate had been provided. The carrot would be an extension east to Whitechapel to link up with the East London Railway which, due to its financial state, was ripe for takeover. In this way the markets of South East London would be opened up.


Whitechapel Station – a major objective that provided interchange with the East London Railway. Again this is an 1896 photo. Note that the station was a Metropolitan District station which, confusingly, was the full title of the District Railway.

In 1879 the Metropolitan and District Railways (City Lines and Extensions) Act was passed authorising the extensions to Whitechapel from Aldgate and Mansion House. Furthermore, the act not only authorised the very short link between District and Metropolitan Lines between Aldgate and modern-day Tower Hill (to complete the circle) – it required a Circle Line service to be provided. Clearly parliament were well used to the antipathy of the two companies involved and were determined that they would be forced to provide a Circle Line service.


Mark Lane was the forerunner to Tower Hill station. The station seemed to be fairly basic.The absence of a railway company name prominently displayed is surprising.

It is not clear how the Circle Line fared in its early days. In later years it caused a lot of problems that no other line experienced. The problems with running trains in a closed loop are many. Operationally the biggest problem has always been that if you are late you can’t make up time by reducing turnaround time at the terminus. In the early days the lack of a terminus meant that you had the added problem of having to change locomotives in something rather equivalent to a modern pitstop and then, in the confined space available, quickly re-water and re-fuel that engine so that it could be ready to take over from another locomotive in just a few minutes.


An early 20th century Underground Map.Note the total absence of any reference to the Circle Line.

Operating Problems: You cannot lose time

On the London Underground you can’t give the Circle Line trains extra time because they share the track with other trains on different lines. Indeed there were just two places where they could wait in a platform to lose time without affecting other trains – Aldgate and Gloucester Road westbound (clockwise). Edgware Road did at least provide some further saving grace as there was also a bit of leeway because the only service affected was the Hammersmith & City which ran at the same frequency and should have been at least four minutes behind the Circle Line train. Older readers may well remember that Circle Line stops at Edgware Road would always seem to involve an interminable delay waiting in a train carriage with all four double doors open in one of the few platforms of the Circle Line that is directly exposed to the cold winter air.

It follows from the inability to have much “slack” that it is important that circle line trains run to time. Unfortunately in London the Circle Line encounters a number of flat junctions and all are intensively used. These are Praed St (near Paddington), Baker Street, Aldgate, Minories (north and south of Aldgate station respectively) and Gloucester Road. Fairly self evidently these junctions are only a problem on the outer rail (clockwise) service. The inner rail (anti-clockwise) service has no conflicting junctions at all during normal working.

If losing time on a circular line is difficult then gaining or recovering time is next to impossible. Skipping stops is not a realistic option on the London Underground for anything other than the Metropolitan Line. More aggressive driving can achieve a limited effect but is generally only condoned on ATO lines when it is controlled centrally. Terminating short of destination does not work on a circle line and neither does taking advantage of the built-in recovery time at a terminus. A basic rule of thumb: Continuous Circling Compounds Delays, Terminating Trains Absorb Delays.

Other Operating Problems

Other problems can include the issue of the driver needing a physical needs break (go to the toilet), what to do with the train if a relief driver does not appear at a crew change and uneven wear on the wheels if a train consistently goes round in one direction. In London problems are compounded by it being impractical for the depot to be on the route of the line itself.

A further problem is that it is very difficult to change the number of trains providing a service during the day so off-peak and peak hour services are run with the same number of trains. One might expect peak hour frequencies to be the same as off-peak frequencies but it is actually worse than that because it takes longer to make the journey in the peak. Depending on the timetable one has to offer a fixed number of trains per hour and realistically, at best, one can go to the odd half a train per hour. So in its later years, when running as a circle, the Circle Line off-peak service at 7.5 trains per hour (tph) was actually better than the peak service (7tph).

If all the above were not bad enough, the continuous Circle Line was a very unpopular duty made worse by the fact that the journey was all most entirely in tunnel and very repetitive without a break. This led to union agreements about the maximum number of circles that could be done without a break and the maximum that could be done in a day which then constrained the duty roster for the timetable. So not only was the line difficult to run, it was also difficult to timetable.

If it is a bad idea – why do it?

An obvious question to ask therefore is why, if it was known to be such a bad idea, did the Circle Line remain as a service? The answer seems to be that, despite its known horrors, it was just too difficult to get rid of. In fact one could argue with some evidence that London Underground and its predecessors spent an entire century trying unsuccessfully to get rid of the Circle Line.

Frank Pick’s dislike of the Circle Line

Frank Pick was one of the people, perhaps the main guiding light, whose influence even today is largely responsible for making the London Underground an organised well-designed integrated product. Back in 1919, as commercial manager of the London Electric Railways Group, he had already grown to dislike the Circle Line. No doubt the awkwardness and difficulty of operating the Circle Line would have been totally contrary to the simplicity and sense of order that he strove for. More particularly, in 1919, he disliked the fact that the Circle Line was taking up running slots that he believed could more usefully and more profitably used to bring in what we would now call commuters from further afield.

In 1919 the District Line to the west would have had branches to Wimbledon, Richmond, Hounslow, Ealing Broadway and South Harrow. It could have been worse but at least by now the Middle and Outer Circle no longer ran. One could have understood Frank Pick’s frustration. It seems that, in essence, he thought that by abolishing the Circle Line you could replace each Circle Line train by two starting from a District Line branch in the west. One of these trains would be a District Line one taking up the southern slot via Victoria. The other would be one from the still-rival Metropolitan Railway which would go via High St Kensington and the northern part of the Circle Line and continue to East London. Nothing came of the idea which may have been, in part, because the plan may have required the repeal of the clause in the 1879 act requiring a Circle Line to be run.

Looking at an old idea in a modern context

It probably worth looking at Frank Pick’s idea in a little more detail because in a modern content it actually reveals an awful lot about the Circle Line and ideas in planning underground lines in general.

The modern equivalent of Frank Pick’s idea would be to send a Circle Line train starting from Hammersmith (Hammersmith & City and Circle Line station) then continuing around the circle via Aldgate but from Gloucester Road it would leave the current Circle line to divert to Earl’s Court and then down to Wimbledon. It would then return to Earl’s Court and go via High St Kensington to Edgware Road taking up a Circle Line slot for its critical path through Praed St junction.

The crushing flaw in the plan would appear to be that altering the Circle Line like this would increase the number of sub-surface trains through Earl’s Court by about 50% which nowadays is simply not possible. One wonders if Frank Pick had any plans to deal with this or whether it would not have been a problem in 1919 or he had simply overlooked the issue?

What is possibly more interesting is to look at a variant of the scheme where one avoids Earl’s Court by sending trains Wimbledon trains to and from the south part of the Circle Line via a new link (possibly via King’s Road, Chelsea). Then one has an opportunity to bring many more people into the centre of London. Nowadays this however would be considered irresponsible because one is increasing capacity into London without increasing capacity within London.

The modern approach would probably be to reduce the number of Underground branch lines by providing a new central section. This cannot be done for the District Line alone because there is only one branch to the east. One could however take over the branch of another line such as the Central Line. So a line from Wimbledon to Epping would neatly free up extra capacity on the District Line and the overcrowded Central Line. This is, of course, a variation of the proposed Chelsea-Hackney Line which for around forty years was seen as the way forward – until Crossrail 2 proposals came along.

The other reason that Frank Pick’s idea is so interesting is that it really enables us to give an good answer to the question “What is the purpose of the Circle Line ?”. Turning Frank Pick’s idea on its head, one could argue that the purpose of the Circle Line is to use otherwise unusable capacity between Aldgate and Edgware Road via Victoria.

The idea of getting rid of the Circle Line will not go away

In 1933 the London Passenger Transport Board was formed and the Metropolitan Railway and the District Line came under the same organisation. Frank Pick was its Vice-chairman. Today we would probably have called his post “chief executive”. As well as day-to-day issues the board quickly got themselves involved in initiating solutions to outstanding major transport issues. We have already seen their initiation of a scheme for new tunnels between Finchley Road and Baker Street and for the Bakerloo Line to take over the hopelessly overcrowded Stanmore branch and most inner suburban stations of the Metropolitan Line.

Another thing the board did surprisingly quickly was to get the clause in the 1879 act requiring a Circle Line to be provided to be revoked. This they had done within 16 months of being in existence. It would not be hard to guess who probably was the driving force in getting the relevant clause repealed.

In April 1934 Frank Pick was already writing to Kensington Council supplying details of a proposal to run a shuttle service from South Kensington to Edgware Road and promising the reconstruction of South Kensington station to provided cross-platform interchange with the District Line there. This was no doubt do-able but would have been enormously disruptive and expensive with a need to keep a service running most of the time.

It is not surprising that nothing became of this proposed South Kensington – Edgware Road shuttle and it is difficult to see any real tangible benefit in providing it. At first sight one can put this down to one man and his obsession. It may well be though that the reason for pursuing this idea had changed. We know in that by 1928 the section of the Underground between Mansion House and South Kensington was the busiest two-track section and on it during the rush hours an incredible frequency of 40tph were timetabled. This would have been very difficult to sustain especially as usage went up and it may be that Pick was not planning to run more trains but fewer. In other words this section was probably running beyond its sustainable capacity and the least painful way to sort it out was simply to stop running the Circle Line trains through it.

It seemed that at the time it was only Frank Pick who was determined to see the elimination of the Circle Line happen and he was already not in the best of health. When he died in 1941 it seemed that the this scheme died with him. Obviously there was a war on and any further consideration would have to wait until the cessation of hostilities.


Frank Pick in 1922.Even he appeared to find the problem of eliminating the Circle Line beyond his capability.

The Post-War Plan

Frank Pick’s plan may have died but the idea of getting rid of the Circle Line had not. In 1941 relocated Circle Line platforms opened at King’s Cross. Previously they had been inconveniently sited next to what is now the former King’s Cross Thameslink platforms. Included in the rebuilding was an extra platform between the running lines to conveniently terminate trains from the west. The original plan was that is would be used for extending some of the off-peak trains that then terminated at Baker Street. This did not really make much sense. Why bother? Alternatively why not terminate at Liverpool Street or Aldgate? It was now proposed to make use of this for a “turn and a half” Circle Line service.


The original Metropolitan Railway station at King’s Cross photographed in 1934 shortly after the Metropolitan Railway was taken over by the London Passenger Transport Board.Note the diamond in the station name sign which was uniquely a Metropolitan Railway feature and the name on the board was King’s Cross & St Pancras which was the Metropolitan Railway name for this station.

The idea this time was to start at Putney Bridge, go to Edgware Road and from there to a complete circuit of the Circle Line before continuing to King’s Cross. No explanation was offered as to how Earl’s Court would cope with the extra trains. On the Baker St – King’s Cross it was proposed to introduce speed controlled signalling to handle 40 trains per hour. The speed controlled signalling could be thought of as very crude Automatic Train Protection system with the control mechanism being track based rather than train based.

It is not surprising that the turn-and-a-half scheme came to nothing. For starters it had the feel of someone starting off by trying to make use of an unused recently-built potential asset (that platform at King’s Cross) rather than solving a problem. It was also quite expensive in cash-strapped post-war Britain as it involved making the terminating facility at King’s Cross fit for use, extra rolling stock and signalling changes. In retrospect it is hard to believe that it wouldn’t cause as many problems as it solved.

A further complication to the original turn-and-a-half proposal which was originally made in 1948 was that proposed railway plans for a post-war London were being optimistically firmed up and one of the proposals was a route ‘C’ from Walthamstow to Brixton. This would clearly compete for funds and management time. There was also a proposal for a variant on route C to go to Fulham Broadway after Victoria and from there take over the District Line to Wimbledon. This was now seriously complicating the issue. With the Victoria Line serving King’s Cross it was questionable how useful additional trains on the Circle Line would be and, as well as that, the impact on of route C going to Fulham Broadway would now have to be taken into account. The turn-and-a-half scheme was dropped and revived again then died a death in this particular form for a final time. The scheme followed the 1949 Bakerloo Line extension to Camberwell in a list of “what might have been” for the period.

Further Ideas

The last decade of the 20th century saw some further half-hearted schemes. A couple of them seemed more intent with trying of find a use for the much-unloved 1983 stock that was replaced on the Jubilee Line in preparation for the opening of the Jubilee Line Extension. A simpler, more sensible was the idea of simply getting the Hammersmith & City Line to do a turn-and-a-half. This was actually put into practice for the Notting Hill Carnival in 1990, 1991 and 1992.

The idea of the turn-and-a-half Hammersmith & City for daily use was ultimately rejected on two grounds. The first was because of the limited ability to recover from major delays. This does sound surprising because it surely had to be better than the arrangement then in existence. It also seems completely at odds with what eventually happened which is really remarkably similar in concept although operated as two separate services. The second reason for rejection is that it was too complicated and too confusing for passengers. Apart from possibly suggesting that Carnival attenders must have higher than average intelligence, this seems inconsistent with experiences abroad – as we shall see in part 2. This reason for rejection also seems inconsistent with what actually subsequently happened which is very similar in nature.


Yet another 1896 photo. This one is of Cannon Street station. This station, along with Monument and Mark Lane, was then jointly owned as is clear by the signage.

It is clear that, despite every attempt to break the continuous circle being either stillborn or regarded as unworkable, London Underground had not given up the idea of getting rid of a continuous Circle Line. To quote the final paragraph of the book “The Circle Line” (see below):

Finally we have Mr Derek Smith, then managing director of London Underground, addressing the London Regional Passengers Committee on 24th November 1999 – ‘The Circle Line’s contribution to the totality of the network is not large, and it makes control of shared lines difficult. It is not the right design, and in the long term the question is whether it should continue’.

In part 2 we look at how London Underground tackled the issue of the Circle Line in the 21st century. For comparison we also look a few other cities and see how they deal with this issue.


This picture was taken in 1902 and features in many books. It may well be the only known photograph to actually explicitly reference the Inner Circle. It is a picture of Aldgate Junction taken from the north end of Aldgate station. Note the very limited space to service the locomotives. The locomotive in the siding has a board that says NEW CROSS as for a few years the Metropolitan ran through services to New Cross (SER).

The bulk of the background for this article was either obtained from or verified using The Circle Line by Desmond Croome. Like all books in this series it packs an awful lot of information into its 80 pages and is highly recommended for further reading although it pretty much stops at the end of the 20th century. Despite the title it also includes coverage of the Hammersmith & City Line from Hammersmith to Paddington.

Our thanks go to the LT museum for allowing us to use their photos.

Written by Pedantic of Purley