I recently heard a proposition that ‘technology’ was the name given to a development that did not yet work. Once it did work it would be called something more appropriate: a chair, computer, power source, or whatever. I’m not sure I fully go along with this, but I take the point. Implicit in this is that when technology is being developed there will be little to provide any form of guide, and ideas that we might today consider barmy must be examined because it was simply not known they were barmy then.
It is with this in my mind that the subject of traffic lights struck me as an example. We more or less take traffic lights for granted these days. They are an entrenched part of the street scene and exist in enormous numbers, ordering about traffic across the world and sometimes attempting to order pedestrians as well. The explosion of traffic light numbers is comparatively recent, but in the UK they are really a creation of the 1930s, creeping in very gingerly at a small number of busy locations and mainly developing post war.
Prior to light-controlled junctions there were huge numbers of junctions that were controlled by policemen. The task was called point duty as the policemen were appointed to each ‘point’ on a rota basis. By means of hand signals a single policeman would hold traffic on certain roads at a junction and pass traffic on others. To stop traffic he would step out in front and hold his arm up, palm ahead. Traffic would stop and not restart without permission. Having stopped one road he would turn round and stop the opposing flow. All now stopped, he would then select the cross-route and beckon it forward, swivelling round to do the same with the traffic waiting in the other direction. There were no signals other than those given by the policeman, but on whichever route was in flow at the time he would usually make recognized hand signals to encourage the flow to continue and remove any doubt as to what was wanted. It was a good system in that officers developed a thorough knowledge of each junction and in the event of congestion knew what had to be done to clear it. My father had been a police officer in London’s West End and reminds me that at large junctions two (and occasionally more) officers were needed to manage them and had an agreed code between them so that they co-ordinated actions (one can imagine getting this wrong could be quite exciting).
St Giles Circus was one such junction; my father managed it occasionally and tells me that when he was holding traffic back he had to stand in the road with his hand up, but back to the traffic so he could monitor what was going on. It was a great sport of bus drivers to creep up behind the officer and get the vehicle as close as it was possible to do so but short of touching him. The officer on duty could hear it creeping up but as a matter of honour would not turn round – the officers knew the game and could identify the drivers from how close they dared approach.
Of course this was all an immense drain on manpower and there was a great deal of interest in some kind of automation. It was therefore not a matter of great surprise when in due course the police mind pointed out that road junctions were rather like railway junctions where trains obeyed light signals operated from one central point. As automatic systems did not already exist in this country it was not then obvious that road junctions are not really like railway junctions, but they didn’t know that then.
The corporate police mind was sparked into action by police constable Miles, of Gray’s Inn Road police station. PC Miles had been a draughtsman at Devonport Dockyard in Plymouth, but had moved to London about 1920 to become a policeman. Within a couple of years, he had begun to study the problem of London’s traffic in his spare time and had even visited Paris to examine French methods. This caused him to contemplate an electrical solution, and he applied himself to designing one. Work on his electrical device had been completed in the late autumn of 1925 and a patent was then applied for.
The ingenious system, then regarded by Scotland Yard as, ‘one of the cleverest of the many they have examined’, was demonstrated before the London & Home Counties Traffic Advisory Committee around the beginning of January 1926. This was sufficient for the committee to approve a six months’ trial being made in Piccadilly, with the junction of St. James’s Street, including several other side turnings. A further practical experiment was arranged for the end of January 1926.
By this time, what had started off as a relatively simple system was now contaminated by railway thinking and the misguided but logical conclusion that, like a railway junction, a completely interlocked lever frame was required. An order was placed by the Ministry of Transport with The Westinghouse Brake and Saxby Signal Company Limited of Chippenham early in 1926. The frame was a Style K frame, number E28 and was completed in July 1926. A nine lever frame was required, one lever being spare. Naturally the frame required to be located in a kind of signal box occupying a commanding position, though the word signal box was never used and it was called a central control cabin. This was 3 feet 3 inches by 6 feet 6 inches, with glass sides, and would house the control apparatus. The frame would be operated by the person in charge of the junction and would operate outside signals.
Eight signals were to be erected along Piccadilly between Berkeley Street and Old Bond Street. One description states that each signal was to be 10 feet 6 inches high with green and red lenses and that the posts were to be green, with transformers mounted on them. An early description suggests that Signal arms were to be used by day and the colour lights by night. It would take six men, including the operator, to control the traffic, whereas it was taking nine men before the system would be introduced. According to Police Review, the cost of the installation was said to be £650, but a saving of £1,400 would be made. The Westinghouse plans indicate that the lower lamp would be the red one, which was normal railway practice (the reason for red being at the bottom is said to be that in the event of snow there would be nothing underneath to obscure the view, while the hoods, required to reduce the reflection of the sun, might allow snow to obscure the lens above. It was vital that the stop signal was never obscured). I have not myself seen these plans yet, but the signal arms would probably have been like railway semaphore arms. How they would have been operated I cannot say.
What was actually installed was different. There were no signal arms and there were three lamps at each location, with red at the top. According to Modern Transport, the colours were to be red for ‘halt’, green for ‘proceed’ and yellow, the latter bridging momentarily a period between ‘halt’ and ‘proceed’ to allow for the slowing down or getting ready to move as the case may be.
The Times of 28 April 1926 reported that ‘Purely as an experiment, a system of light signals to control cross traffic in Piccadilly from Berkeley-street, as far as the Circus will be tried in about a month’s time, but experience alone can show whether there is likely to be any gain in traffic speed by establishing regular intervals for traffic to move out of the side streets on the northern side of Piccadilly from Berkeley Street East.
On Saturday 31st July 1926, the system had a brief try-out, no doubt to familiarize those who would be responsible for its operation on a daily basis. Power was obtained from a connection to Devonshire House.
Tuesday 3rd August 1926 was the first full day of operation of the new system. This was inaugurated by P.C. 234 C, watched by hundreds of people who had lined the pavements or crowded around his control box to see the system working. Traffic proved to be light, causing The Times reporter to comment that, ‘it did not provide a real test for the system’. However, it did allow the police officers to gain experience in its working.
One might think that the installation was intended to give direct instructions to vehicle drivers, but this was not so. Perhaps because motorists would not have understood what was required and perhaps because legislation might have been needed for the law to give meaning to them, the lights were used only to inform the police officers actually in charge of the junction. The mode of operation was therefore for the police officers to monitor the lights and repeat the instructions using the conventional hand signals that were backed up by law. There is no evidence that the signals were ever allowed to operate without the ‘pointsmen’, as the police offers were called. Evidence to the contrary may yet turn up, though.
In a paper to The Institution of Electrical Engineers on 10th December 1930, it was suggested by the authors that ‘A difficult location was selected and if the installation has not been a success entirely, it has provided experience. The location later received an automatic installation. The fate of the Westinghouse signal frame is unknown.
As this ‘technology’ gradually evolved into a working system of traffic lights there has never been, so far as it has been possible to ascertain, any other instance where railway signalling equipment has been used. It is now accepted that the objectives behind junction control are entirely different and that cars behave differently to trains and need a bespoke solution. Nevertheless, so many technologies are now converging that it may well be that one day a black box used to control railways will be the same black box that could operate a traffic light system, and that only the programming will differ.
I am only aware of one other example of a novel use for a signal frame, and that is the purchase of a London Transport style V interlocking machine from Westinghouse by the Atomic Energy Authority, apparently for use in an unspecified atomic power station in the 1950s, very much still in ‘technology’ phase. This remains to be looked into, but presumably the authority was taken by the facility for mechanical interlocking to prevent some disastrous sequence of operations being possible. They only ever bought the one, so perhaps some other solution was found. Readers may have further knowledge of unusual applications for railway signalling apparatus.
The following pictures show the control cabin and the signal lamps. They are extracted from Wonderful London (1930) and the originals are not very clear. If I can find some better images I will put them in.
Complete style K lever frame in control cabin, each lever complete with catch handles. The ninth lever is on right set back.
View of a traffic signal, the head closely resembles contemporary railway signal.
This view shows the control cabin near centre of photo, at head of the cab rank. One road signal is visible. There is no obvious sign of a policeman, but the photo may have been taken when lights not in use.
I will just sign off by observing this was not the first attempt to use some kind of mechanical or automated system in the UK. A device was installed in Bridge Street by parliament in 1868 using a moveable arm to stop traffic during daylight and red and green gaslit lamps at night. The signals were displayed by controls operated by a policeman. Unfortunately the gas leaked and the device exploded on 2 January 1869 and killed a policeman, which put paid to the idea.
It can be no surprise that it was the Americans who first perceived the need for traffic signals as the motor age advanced. The first was in Cleveland, Ohio, in August 1914, just using red and green lights. A 3-colour system operated from a tower appeared in New York in 1918 and in Detroit in 1919. 1922 saw the first electrically synchronised traffic signals installed in Houston, Texas.
An early British example was installed by the Brighton police at the Seven Dials junction in Brighton. This consisted of a pillar adjacent to the left hand side of the road at the junction, with a signal arm which was capable of descending with the word ‘stop’ on it. A bell was put on top of the post and this apparently rang if a motorist did not observe the signal. The system was controlled by a policeman in a covered ‘pulpit’ located in the centre of the Dials, which had a rear view mirror to enable all the roads to be surveyed at the same time. This system of traffic control also allowed trams to traverse a sharp corner in safety, other traffic having been halted by the signals.
The first automatic system was installed in Princes Square, Wolverhampton, in November 1927, on an experimental basis and were made permanent in 1930. The first vehicle-actuated system was at junction of Cornhill and Gracechurch Street in 1932. This was the same year that the first pedestrian controlled crossing lights appeared in Brighton Road, Croydon.
If you want to know a bit more about traffic lights than might be healthy, you can click the link HERE.