The tube was the first passenger railway in the UK to adopt any form of automated train control or rather as it was known in those days, Centralised Train Control (CTC.) This was indeed the first in Europe and was installed on the Metropolitan Railway’s new branch to Stanmore. It opened in December 1932 and though the CTC was largely working by then, 1933 was the year it was fully completed. That too was the end of the Metropolitan Railway as it became part of the new LPTB. The Stanmore branch itself was soon transferred to the Bakerloo Line and lost its unique status.
In terms of true automated railway operation this wasn’t even anywhere near this. It was another underground railway that had led the way even earlier than the Metropolitan’s novel and subtle approach. The honour goes to the Post Office Railway which started out as a fully automated railway from its inception in 1927. Sadly passenger railways would not be ready to take on this challenge properly head on for another forty years. The Stanmore branch’s unique status lasted barely five years before it was replaced by a more conventional and manual means of controlling trains.
The official opening train on the Stanmore Branch 9th December 1932. Source: Twitter
For the introduction of the Bakerloo Line conventional signals and a signal cabin were provided. Remote operation of the branch’s trains (apart from the semi automatic signals installed by the LPTB) did not return to the Stanmore branch until the Jubilee Line had arrived and was converted to ATO in the early 21st century.
The inaugural train at Stanmore. Source: London Reconnections
Many sources say the line opened on the 10th December however some say the 9th. Which is right? The 9th because there’s a report in The Times printed on the 10th December mentioning the line had ‘been formally opened yesterday.’ The 10th December was when services properly began (meaning it opened to the public on that day.)
What the Metropolitan railway had done in the 1930s was unheard of. It was a major step forward and showed the current technology was quite capable of doing a job without human intervention. Who needed humans when ‘robots’ could do the job? Clearly the design of the Stanmore branch was done in a way that the trains would practically operate independently of the signal cabin at Wembley Park.
Poster advertising the new services. Source: Reddit
One of the first questions to ask is why did the Metropolitan Railway decide on such a drastic and largely untested means of automated control for its trains? Its likely that in view of the length of the branch and that practically all the trains would be simple out and back services, there wasn’t really any need for signallers along the line. In fact Stanmore station in those early days consisted of just two platforms and a single siding. No complexity thus things could be kept very simple. The siding required control from Wembley Park of course but besides that trains entering and leaving the station itself were largely done without any intervention. The signallers at Wembley Park could see what was happening by way of their track diagram and they could intervene if it was necessary.
With all the other existing tube termini all a signal box did was to receive and dispatch trains. A simple cross over or a simple run straight on or out. No complexities of any sort. Thus the railway’s directors must have decided at some point this work could be done automatically. Of course the savings in construction of a number of signal boxes and extra staff would too be a advantage.
Metropolitan Line & Stanmore on the map. Few would realise the branch was a totally different ken to the rest of the system! Source: London Reconnections
The Stanmore line was the first of its example in Europe but not the world however. Automated signals are nothing new on the tube these have been in use since the very early days though largely in a capacity of automatic train protection (eg setting a route to red once a train had passed.) The more complex routes, junctions, stations, continued to remain under the control of station staff or signalmen.
Stanmore however entailed a basic element of automated route setting, which is why it was so radical at the time. The system set the route the trains would take – even though it was a very simple operation involving the movement of an incoming train into either platform that was available, and the same again for the reverse operation onto the up line towards London.
Since the 1910s however various American railways have dabbled in these far more advanced types of automated control and ironically the American influence is quite important in terms of Stanmore. That is because a lawsuit was in fact issued against the Metropolitan Railway’s contractors by an American company who claimed the Stanmore CTC system had in fact been stolen from their patents issued for the railways in the States!
Stanmore station. Opened by the Metropolitan Railway on 9 December 1933. Transferred to the Bakerloo 1939 and the Jubilee Line 1979.
The Stanmore CTC system
The CTC scheme involved control of the entire branch from Wembley Park signal box. At the time this was met with amazement, even disbelief, by many for it was the furthest away from a signal box that trains had ever been controlled in this country, this being a distance of almost four and half miles.
Naturally the new line opened with no signalboxes to be seen anywhere – and it was something totally unheard of. Imagine that! A new passenger railway without any sign of any humans anywhere in charge of its overall control. The friendly signalman was nowhere to be seen.
This new and radical system was decided upon by no other than the Metropolitan Railway’s signalling superintendent, R. Falshaw-Morkill and it was likely drawn up and agreed upon at the line’s headquarters in Baker Street.
The sub-station at Canons Park which was once the heart of the Metropolitan Railway’s CTC system.
The installation was by Westinghouse Brake and Saxby Signal Company and cost £6,945. Some reports suggest the entire branch was CTC controlled (for example Locomotive, Railway Carriage and Wagon Review 1934) however just Stanmore station itself had direct CTC control. In other words, as as already been mentioned, the arrival and departure of trains at Stanmore was automatically controlled.
By large the system got on quite well without the need for human intervention. The rest of the branch was controlled by an automatic system consisting of three aspect lights working on A.C. circuits fitted with train stops. Nine semi automatic signals and five interlocked power cross-overs were also provided.
The starter signals at Stanmore station. Source: Railway Wonders of the World.
A substantial interlocking facility was installed near the junction with the branch to the south of Preston Road, this building being much the same design as that at Canons Park. The Preston Road building provided the control for automatic operation of the line as far as Stanmore.
Equipment for the new CTC scheme included:
6 short-range colour-light two-aspect signals. 9 colour-light shunt signals. 11 ground shunt signals. 6 shunt route indicators. 3 long-range projector route indicators. 1 warning signal. 2 call-on signals. 35 point machines. 21 train stop machines. 69 track circuits. 9 train-starting devices. 8 telephones at signals. 3 double-sided public train indicators.
Power supply for the CTC came from the new sub station at Canons Park. This had special transformers required to power the unusual 440 volt output necessary for the CTC. A back-up installation too was provided at the site near Preston Road.
Freight services over the Stanmore branch were still operating until 1936 at least, and worked by steam locomotives thus it seems the new CTC clearly had to control these services too. One problem with the CTC was it was specifically designed to work with electric train stock, yet there are pictures showing steam operated passenger trains on the branch when no electric stock was available.
Picture showing the line panel at Wembley Park (‘Edgware’ is clearly an error and should read Stanmore.)
Clearly the CTC was built differently to what was found on much of the Underground, (eg automatic signals and air operated trip cocks.) That would explain why steam services were not really suitable for the branch. It is known the CTC had problems detecting these trains and it seems likely the freight workings had been withdrawn by 1936 to ensure total CTC compatibility.
The signals at the junction near Wembley Park were fully automatic and to accommodate these freight or passenger steam workings coming off the Stanmore branch, a special arrangement was in place at Kingsbury. This included a plunger which the steam locomotive’s driver or fireman had to activate. This was necessary to prevent their trains venturing onto the main Metropolitan line totally undetected by the CTC. From this we can deduct on the whole CTC worked fine but wasn’t entirely successful because of its inability to detect steam hauled trains.
This picture shows the CTC apparatus was specially for electric trains – not steam!
Wembley Park signal box was equipped with a panel showing all the track and signals on the Stanmore branch so they could keep an eye and make sure everything was okay and of course they could over-ride the signals if the need arose. I am certain there must have been a warning indicator that alerted the signalling staff to the presence of a steam hauled train coming off the branch, as special procedures had to be taken to ensure the safe operation of the junction with the branch.
Apart from the previously mentioned switch or lever on the southbound platform at Kingsbury, again there’s very little detail how the CTC system actually coped with non-electric trains.
The Stanmore CTC scheme is taken to court
During much of the CTC’s working life there was legal dispute regarding the rights of invention and patents. It was alleged that Westinghouse had infringed upon the patent – which the courts insisted belonged to the General Railway Signal Company (GRS). This company had several CTC schemes successfully operating in the US under what was known as Bushnell’s patent.
That claim was somewhat dicey as in a further twist GRS itself was in battle with other US companies over who had the rights to the patents for CTC. It seems GRS were simply trying to protect its interests this side of the pond. Hauling Westinghouse before the court, GRS claimed:
In or about the year 1932 the Defendant Company manufactured, installed, sold and supplied for use on the Metropolitan Railway, between Wembley Park and Stanmore Stations, an installation of signal control. This installation provided a system of what is known as “centralised traffic control” and is referred to in the Pleadings as a “C.T.C. installation.”
It seems GRS’ attention had been caught by an article in the Railway Gazette for 17 March 1933 describing the new CTC scheme at Stanmore. GRS claimed the CTC patent was theirs and Westinghouse had infringed this. A very detailed examination of the various installations, including those in the US, was undertaken by the courts.
The High Court, sitting on 23 August 1939 before Mr Justice Morton, ultimately decided the Stanmore CTC system had not infringed the patent and GRS were ordered to pay the Defendant’s (Westinghouse’s) costs. There may have been some desire to remove the entire CTC system before the legal action began in order to avoid further recourse. However LPTB insisted the system had worked well and they claimed it had been removed was because of the change over (or rather upgrade) to the Bakerloo – not because of the legal action.
The Bakerloo Line arrives
The new Bakerloo to Stanmore! Source: Twitter
The Metropolitan Railway’s early form of automated train control sadly didn’t last long. The branch had to be upgraded for its transfer to the Bakerloo Line and conventional signals were put in instead.
Records show the CTC system was removed in May 1938. This was a whole year before Stanmore acquired its first and only signal box, which stood on the west side of the station throat.
1978. This view shows the now demolished Stanmore box. The site is now occupied by platform three. Source: Ebay
There must have been some temporary arrangement in place for a year between the removal of the CTC system and the opening of the new Stanmore signal cabin. Perhaps lineside staff were used in that interim period although I cant find any suggestion this was done.
Stanmore station. The new platform three road at far right runs through the site of the 1939 signal box.
A conventional brick box was opened at Stanmore on 29 May 1939. The LPTB’s works to expand the Stanmore branch somewhat preempted matters as it required a conventional signal system in readiness for use by the Bakerloo Line thus by the time of the said legal hearings the allegedly infringed system was no longer in use.
As I have said, the introduction of the Bakerloo Line wasnt really anything to do with pre-empting any court action but rather to improve the line – although sadly the five year old CTC equipment was no longer needed. Its possible it was thought the system wouldn’t be able to cope with the frequencies that would be introduced on the new tube line.
The following picture shows Wembley Park box after the CTC had been superseeded:
What remains of the CTC scheme?
As far as I can ascertain the only remnants of this early 1930s CTC scheme are the sub stations at Canons Park and that near the junction with the Metropolitan (similar in design to Canons Park) and of course Wembley Park signal box itself.
Wembley Park signal box – an important part in the history of railway signalling and control due to its major role in the 1932 CTC scheme.
It must be remembered this signal box wasn’t built as part of this scheme, but was pre-existing on the Metropolitan Railway and suitably modified for the CTC. This signal box thus gained a whole different status compared to the tubes other boxes.
The Canons Park facility included generators and switchgear. It was quite an advanced installation. The power to this (and the one at Prestons Road came from the Metropolitan Railway’s power station at Neasden.)The official opening ceremony of the Stanmore Branch in 1932 also included a tour and inspection of the Canons Park building.
The Canons Park substation which was built by the Metropolitan Railway Company.
The Canons Park substation was the most important element in the whole works. That is what the publicity tells us. I am not sure how it worked in relation to the Preston Road facility however. Nevertheless Canons Park provided the power for the entire scheme and was built on land bought from the Canons Park Estate. Early pictures show this building to be practically in the countryside. However after WWII the estate land was sold off and an industrial estate was built – one that would be important since it included a number of government buildings and research facilities.
The Charles Holden influence
When one looks at the Wembley Park signal box one wonders if Charles Holden got his ideas for brick boxes with concrete lids from that? Who knows!
Another ‘brick box with concrete lid’ can too be seen at the side of the Metropolitan line towards Preston Road. This sub-station too was built by the Metropolitan Railway Company and not Charles Holden!
The sub-station near Preston Road, built by the Metropolitan Railway.
Its interesting that its quite obvious the MR had first utilised the ‘brick boxes with concrete lids’ (as seen in Wembley Park signal cabin) before extending the design to its two new sub-stations. The brickbox/concrete lid concept was popularised by Charles Holden, which begs the question was it the MR who came up with the design or was it Holden? It was the MR who came up with it but Holden took the concept further.
In terms of the Metropolitan Railway/Holden influence, Queensbury station is to all purposes a Charles Holden station – and many would mistakenly assume it was in fact Holden’s work – but the architect in question was in Charles Walter Clark (apparently nicknamed ‘Clarkitect’) who designed all the Metropolitan’s stations between 1911 and 1933.
The tube sign at Queensbury – designed by Charles Walter Clark or Charles Holden?
Taking this further, if one looks at old photographs of the platforms at Queensbury they too came with the very same lamp standards the one and only Charles Holden had designed! Clearly it seems Holden had some influence on these designs.
The stations at Stanmore, Canons Park and Kingsbury will have been Clark’s very own work (which explains the different styling) however the substations and the later Queensbury station (opened 1934) clearly received a considerable influence from the Holden stable.
No doubt by the time the London Passenger Transport Board had been established in 1933 it was decided new designs should be given over to Charles Holden’s critical eye and this is how Queensbury became a Holden station even though Clark was still behind the works to an extent.
Queensbury soon after opening. The Holden influence is undeniable. Source: Flickr
It does not explain however the substations which were built before the LPTB and before Holden even had any hand in the design at Queensbury station. What happened here on the Stanmore branch was likely the crossroads at which these two different design concepts (the Metropolitan/Clark’s and Holden’s) were merged and taken forward as part of the new LPTB modernist look – and that is how its famous Holden era came into being.
Both the Canons Park and Prestons Road substations still supply power to the Jubilee Line. The power cables connection to the Stanmore branch from Prestons Road can be spotted by diligent observers on a Jubilee Line train. These cables utilise the original conduit route built for the Metropolitan Railway’s CTC scheme.
The original CTC power supply route – still in use for power supplies from the Preston Road sub-station to the Jubilee Line.