Why Do We Still Have Semaphore Signals?

Network Rail invited me to take a tour of signalling through the decades, starting with the Littlehampton Signal Box - still operating semaphore signals - through to Three Bridges whree we visit the ASC (Area Signalling Centre) and then the ultra modern ROC (Rail Operations Centre) as well.
The Littlehampton Signal Box is due to close in the new few years … but I also get to ask, why do we still have semaphores signals and where might the last signal box be?
You can apply to Network Rail for a career as a Signaller here : www.networkrai...

[@brianperrie3960]

I was a signalman for ten years around Dundee working in ten different boxes. They were all manual boxes, I did spend some time in Dundee Power Box and learned for to operate the new system installed. People think that the train driver is the man responsible for train safety. Wrong. The driver is responsible for one train, whereas the signalman is responsible for one, two, four, ten or any number of trains. He is the most important man on the railway. I also did ten years as a ticket examiner and finally, twenty years as Station Master in the north of Scotland. I loved working on the railway. I retired at sixty nine after over forty years.

[@JanoJ]

Signal boxes didnt invent computing as such, but we DO use some signalling jargon (interlock, signals, semaphores, tokens) in Concurrent software to prevent conflicts in resources, etc which is exactly what signals on the railway are for!

[@SingleTheShot]

I don't know how I've never made that connection

[@althejazzman]

@@SingleTheShot Me neither! Brilliant bit of trivia.

[@lawrencejob]

it's a precursor in the sense that it was an early application of binary logic; that and textiles manufacturing -- it's a computer in the same input+logic=output sense that Babbage's difference engine is (he and his family have a lot of railway connections)..

[@rafsonrafson]

I'm thankful we hold railway operation to much higher safety and quality standards than software. Wouldn't want to take a train running into a race condition. 😅

[@digitig]

But a *lot* of early computer research was done by the Tech Model Railway Club at MIT, as they automated their model railway system (and created the Jargon File, which standardised and publicised much computer jargon), so terminology crossing from railways into computing was not a coincidence. Computer jargon *does* come from railways. Model railways.

[@abigailcooling6604]

This video reminds me of when Tom Scott went to that signalling training facility that had mock-ups of all signal types - semaphore, 1980's buttons and modern screens - and controlled a little model railway 😊

[@AaronOfMpls]

I'm sure a lot of us were thinking of that one! Thank you Geoff for showing us these on _real_ rail lines now, too. ❤

[@karlmachnow4961]

Its interesting how similar the different signal box types are between countries even though they were all developed separately.

[@shugieshugied2269]

There was something like that at Webb House in Crewe when I did my signaller's courses. Not the modern stuff of course, Motherwell was state of the art at the time

[@jerry2357]

There's a vintage model railway at the NRM that was used to train signallers on the Lancashire and Yorkshire Railway, LMS and BR until about the 1970s.

[@peterfarley3217]

...and thanks to you too Geoff. We're lucky to have you and your quality and reputation gets you in to places normally off-limits for us to see

[@geofftech2]

Thanks Peter, very kind 👍

[@boldford]

Many heritage railways still operate using the same equipment that you saw in Littlehampton SB. It is possible to pre-arrange visits to most of them.

[@jerry2357]

A couple of decades ago, my wife bought me a one-day loco driving course at Tyseley, and apart from driving a saddle tank and a 4-6-0 Castle class and climbing into the firebox of an LMS 4-6-0 under repair, we operated the signal box, a GWR version of the Littlehampton manual box. When I was a student in the early 1980s before privatisation, the university transport society arranged visits to signal boxes. On one occasion we visited Loughborough box (which was a manual box) and Derby box, which was a power signal box, on the same day. I don't know whether clubs or societies could range such visits these days?

[@davidcronan4072]

It's very appropriate that there is a statue of George Boole just outside Lincoln Central Station. The inventor of Boolian Logic paved the way for modern computing. In a way, the old mechanical interlocking still used the basic concept of "go, no go" in deciding if a route was safe.

[@althejazzman]

*Boolean. I'm not correcting you for the sake of it, but you can see how that spelling derives from his name better.

[@jackiespeel6343]

George Boole was linked by marriage to George Everest and Wilfrid Voynich (to take just two of the interesting people in the family)

[@paulkeith9680]

​@@jackiespeel6343George Everest - double glazing titan? 🙃

[@jackiespeel6343]

@@paulkeith9680 No, the mountain man (who said his name differently).

[@benbrist]

Been outside Lincoln Central hundreds of times and never knew this - cool!

[@atlantaman]

Thankfully, Heritage railways lovingly preserve and still operate signal boxes and token systems. Long may that continue and long may we all value and support them.

[@oscarbear1043]

Excellent work, signal boxes are the heart of safe rail operations, equivalent to air traffic control.

[@Sabhoh]

Stop virtue signalling

[@domramsey]

This was a fantastic video, Geoff. Really appreciate the 'story arc' from old to new with soundbites from everyone involved along the way. Really appreciate all the planning and attention to detail here!

[@geofftech2]

Thank you, appreciated! 😊

[@adrienvanderstraeten5465]

It's funny to think that the exact same developement over time happened in Germany: we still have the same mechanically interlocked levers pulling ropes to semaphores (and won't get rid of them any time soon either), lots of signal boxes are operated with the relais push-a-button technology from the 2nd Half of the 20th century and in the last decades we rolled out more and more central operation centers. Same technical logic and developpement, and almost the same technical design over here! Thanks for the very interesting insights, perfectly explained Geoff!

[@sunshiney_Sonnenschein]

And I see that trend away from loco-hauled trains towards DMU/EMU here as well. Especially now with the new concept of the Twindexx (power cars that can haul normal carriages, essentially turning loco hauled trains into EMUs)

[@dasy2k1]

And since 10 years ago (when they merged) the largest player in the UK signalling industry and the German signaling industry is the same company.... The UK traces it's history right back to Saxby and Farmer And the German side (whose name is still used) back to an electric telegraph pioneer by the name of Werner von Siemens

[@timowagner1329]

Ja und heute hat der Fahrdienstleiter mal wieder geschwänzt und es durften keine Züge fahren...

[@ianmurray250]

I have seen UK railway navy census information with births of children in Rouen, France, and Antwerp, Belgium. Having built many of the railways in Britain, British navies were working in, at least France and Belgium, and perhaps further a field, building European railways.

[@frodolon]

Didn’t the federal train agency tell DB to replace their mechanical signal boxes asap because it’s just not possible to maintain the same safety standard as modern forms?

[@thehaprust6312]

I don't know why, but a video with Chris always makes me smile!

[@fuzzynutter8344]

It’s been a while since we’ve seen Chris. Good to see him on Geoff’s channel again!

[@geofftech2]

He always makes me smile too!

[@chrisdenham9086]

Oh you guys!

[@JP_TaVeryMuch]

Mine of information, clearly presented, that's why you guy!

[@Nooticus]

Agreed! Chris had to be my favourite reoccurring guest!

[@dolphbusche]

As a railway signaller myself (allthough in germany) I do really enjoy hese kind of videos! Would love to see more about how signalling is done in the UK, seems to be quite different in some aspects.

[@DubGathoni]

I don't know if there have been major changes since it was made, but Tsets out of Australia does a film about it

[@randomtrainfan6501]

I was so bored couldn't find anything to watch on KZbin and then I see this video. Thanks geoff great job as always 👍:)

[@CNR5154]

Thank you, Geoff and NR for the behind-the-scenes visits. As someone from N America, it is fascinating to see semaphores still used on a sophisticated rail network. It's one of the things that draws me to UK trains. I hope they remain as long as possible. Brilliant video as always!

[@toady446]

Great to see Tim still going strong. He was my Signalling Manager many moons ago!

[@castlehighschool]

The modern signal boxes actually use a lot of the old techniques and therefore it is so important to learn the job from the beginning. As my training as a signal boxer began I started at an old signal box in Bad Neuenahr, Germany which was closed less than a year ago. During the two years of learning you make your way up to the electronic signal boxes. Interestingly you can even see how the newest signal boxes have developed over the years (late 1990s til today) and this make this job so interesting. Thank you so much for giving us a detailed look into Englands signal boxes!

[@mdhazeldine]

I take it the systems in Germany are very similar to ours?

[@castlehighschool]

@mdhazeldine Yes, they are quite similar. Regarding the old technique, the main difference is that while the one shown here uses poles the one on Germany use cables and the levers need to be turned more. Germany then had a mix between mechanical and electric signal boxes which I am not sure were a thing in the UK. The relay signal boxes however look alot smarter in Germany, which (in my personal opinion) is also the fact with the electric signal boxes. After all, they mostly use the same techniques, so it's just more a layout thing.

[@mdhazeldine]

@@castlehighschool We do have some old style signal boxes that have used cables (I think?) and also had electrical/relay panels installed in them at a later date, or use a mix of both.

[@GingerKiwiDev]

totally love this style of video! Thanks Geoff. I watched it while knitting a lace wrap/shawl - which became very relevant just a few minutes into the video. Train signals came in around the time that there was a lot of innovation and invention that led to the various different electronic computer systems we have today. Binary code comes from the Jacquard weaving looms in France developed in 1804-1805 by Joseph-Marie Jacquard that used punched cards to save the code for the complex two colour fabric designs. The first digital computer the "Difference Engine" then the Analytical Engine was designed by Charles Babbage - but couldn't be built with the technology in his time. Ada Lovelace "Augusta Ada King, Countess of Lovelace" (Lord Byron's daughter) wrote the first computer programs for the Analytical Engine. Her mother trained Ada in science and mathematics so she wouldn't end up like the philanderer her father was. ... Which set things up for the ROC to operate today (and NORAD ;-) ). You can see restored 1800s Jacquard weaving looms by visiting The Silk Mill at: "The Silk Museum, Park Lane, Macclesfield Cheshire, SK11 6TJ" Given the industrial revolution history there's a likely really cool railway connection. 🧶🚆

[@mumblbeebee6546]

Many thanks to all three of you and all the others who accepted your presence with good grace! :0) This was a great view behind the scenes, but snappy, and Geoff was smiling so much, it warmed my heart!

[@kevelliott]

In 1976 I was on a 4 week commute between Sunderland, down the coast, to Billingham. The whole line was operated by semaphore signals; the charm of those on their own, ignited my love of railways!

[@mikemainer3009]

As a kid growing up in New York City I was always fascinated on how things worked on our rail network, the subway. Thanks Goeff for reminding me that I still have that little curious kid inside me.

[@LumoTransport]

Hey Geoff just to let you know ever since I saw All The Stations, ive always wanted to visit Corrour and now im staying in the same exact room you did! Thanks for inspiring me

[@oldschoolpaul73]

I didn’t know of your content Geoff, until this got forwarded to me by a couple of pals. It’s excellent. Nice to have met you. Best regards, Paul. Rlf sig at Littlehampton.

[@chrisdenham9086]

Thanks for being a great host Paul!

[@geofftech2]

hey Paul! ah, thanks .. very kind. thanks for having us, and thanks for the tea! we had a cracking day.

[@raphaelnikolaus0486]

Really love stuf fand information like that. Actually think, the general (train riding) public should also know more of this - at least a bit. I also love Chris. What a true sweetheart.

[@adrianincroydon71]

I guess this signalling business is very complicated! I confess I assumed it was all completely automated. It's a real eye-opener to see how much human involvement there is.

[@Tyrannosaurus_Wrexx]

That NORAD room is what we called SCADA, when I operated the light rail train in Dallas, Texas. It stands for Supervisory Control And Data Acquisition

[@althejazzman]

@@denelson83 Did you watch the video? The bit where Geoff compares it to his favourite film.

[@user-lt9py2pu6u]

Back in the sixties when I used to go trainspotting with my mates, I was always far more fascinated with the signals than the actual locos. Where I lived there was a mixture of upper and lower quadrant signals, one of the lines being ex GWR, but there were still some ex LNWR signals along with the more modern LMS and BR signals, there were even a few two and three aspect colour light signals. Luckily I managed to photograph some of the signal boxes and what was left of the gantries during the early eighties before they were demolished. Thank you for posting this interesting video.

[@nmccw3245]

Very cool. The Raton subdivision north of me here in Albuquerque NM is the last US mainline that still uses semaphore signals. They can be seen for now when riding the Southwest Chief, but they probably won’t be around for much longer.

[@EoRdE6]

Love the southwest chief, such a beautiful route, nothing like it in the UK

[@00Zy99]

A replacement project is already underway. If you want to make plans to see them, you are probably already too late. Of course, the semaphores on Raton were not mechanically controlled. They were FAR too remote for that. That remoteness was one of the reasons for their survival. The other reason was their low traffic. Raton Pass has 3.5% grades, and so over the course of the 20th Century freight traffic diverted to the Belen Cutoff and its 1.25% grades. Today, the only regular traffic on Raton is the Southwest Chief, which runs once a day in either direction. It was even threatened with abandonment until the government of New Mexico stepped in and bought it. There IS the possibility of increased traffic if various passenger rail proposals currently floating around happen, but its probably not something to hold ones breath about. The US DOES have some manned towers at particularly critical junctions, but they are mostly used by passenger trains and run by government agencies responsible for those particular passenger trains-most notably in Chicago's commuter rail system METRA. And the primary reason for those remaining is a mixture of lack of financial means and a desire to eventually replace those flat junctions with grade-separated systems. Otherwise, rail traffic is primarily operated remotely (potentially thousands of miles away). For the privately-owned freight railroads, its a question of saving money in not having to employ people at remote towers. I'm surprised that the savings of wages and mechanical equipment doesn't factor likewise across the Pond.

[@JBS319]

I'm pretty sure the last ones just came down within the past year. If not, there's probably only one pair left.

[@paulkeith9680]

​@@00Zy99it's usually the huge cost of replacing it all far outweighs the wages

[@jacobgoerzen]

As of today (8-20-2024) Only 11 remain on this route

[@PokhrajRoy.]

Burning question since 2007 for me, actually. Dreams can come true.

[@shugieshugied2269]

A very different work environment for signallers when you compare the lever box (where some points at a distance from the box could need a lot of effort) to the signalling centre. In many lever boxes the signaller would spend most of their working days on their own, in the signalling centre it appears to be very much more team based, with your line manager on hand much of the time. Good video, and well done Network Rail for allowing it to be made.

[@ANDREWLEONARDSMITH]

Signalling centres are the railway equivalent of air traffic control which is where the concept evolved from.

[@MJMC56]

Fascinating video, thanks. My grandpa, fathers side, was a signalman who died in 1932 walking home along the tracks from his signal box and was allegedly struck by an unscheduled train. Sounds like hooey to me but the train company paid his wife compensation (a pitifully small sum) and she was allowed to live out her days in her railway cottage.

[@paulketchupwitheverything767]

Tim gave a really clear and easy to follow explanation of the signalling machinery. I feel like I've seen several railway films showing a signalman pulling the levers but never the details about the differences in the levers and the machinery and interlocking system beneath. Great blurring effect on the train at 16:55

[@Denjasaurus]

Having a rough time at the moment and your videos always cheer me up

[@homelab-student]

Thanks Geoff, one of your best pieces of documentary film-making in my opinion and that really is saying something given all the great videos you've made to date! 😄

[@geofftech2]

Wow, thank you!

[@pauleff3312]

Really enjoyed this film - thank you for sharing. And well done to the railways people themselves for letting you in

[@mikehill2274]

Thank you Geoff. That was brilliant, and really interesting. I could watch signalling all day. 👍👍

[@favesongslist]

I so enjoyed this, brought back so many memories as my first job was at GEC General Signals, including relay interlocking. I specialised in the use of electronic communications called TDM systems to remote 'relay room' interlocking. BTW modern computing was invented in 1822 by Charles Babbage, predating railway signalling interlocking systems. Reminded me of so many stories I could tell from 50 years ago :)

[@tonyshield5368]

Just loved this signalling YT. What great access and great people to work with.

[@rickyzuc]

I do love semaphore signals, until fairly recently they were still in use on the Greenford branch line and I found it fascinating. You can see still infact an old set of signals from Greenford station on the old Acton-Northolt line. Fantastic video, very structured - loved it!

[@EdgyNumber1]

Travelling by train is awesome and despite what some might think, the people that keep it running - safely - are pretty awesome too. Great video Geoff!

[@davecude2189]

Hello Geoff, nice to see this video. Brought back memories of when I was a S&T Technician on Chichester patch and Maintained the Littlehampton SB. Started on BR back in 1968 when it was all mechanical. Also done faulting and maintenance on the Brighton mainline from Brighton to Victoria VSC and all the branch lines. Nice to see 3 Bridges ASC and the same stairs I used to climb when on shift, here. Signalling has evolved in my many years, many good railway men as well.

[@TheClockwise770]

Great video Geoff, I live near the Littlehampton signal box and have always wanted to see inside it, thank you. Also the North London line still used semaphores until the late 1990s

[@tudibelle]

10:00 thank you so much for showing this. I am always very nervous about level crossings, but knowing these checks are in place, and the diligence that Dean showed makes me feel so much less anxious. Thank you.

[@XineasHD]

Very nice to see the UK version of what will hopefully soon by my job in the Netherlands. I'm currently going through the recruitment process and trainings to become a signaller.

[@paul-88E]

I enjoy all your videos being a train enthusiast/spotter myself. I grew up in South London and know the area well, so this video was very entertaining. Thanks Geoff.

[@siccodierdorp6947]

Wow, this was very interesting. I knew semaphore signalling was still in use in Britain (in The Netherlands the last mainline use of them was in the early 80s, last NX went in the early 90s), but was very surprised that the modern ROC still uses manual signalling. It;''s all automated here with automated pathing commands, our signallers can only overrule when needed.

[@creesch]

It's very interesting indeed as everything in the Netherlands (As you said) is automated with various abstraction layers under it depending on the safety system it eventually controls, although none of those will involve semaphores. It also means that all 12 ROC equivalents (They are called something that translates to Traffic management posts) in the Netherlands are standardized, so they run the same software and have the same hardware where the key difference is the configuration for the area they are responsible for. The UK still having various different ways of doing so and various more legacy systems makes me wonder how much extra cost is involved there. Although I also realize that getting the budget to replace it all is something else entirely.

[@OpenbaarVervoer2D]

I love how all these buildings breath all the different eras from the 19th century, up till that 70's office look and then all of a sudden Beautiful green tiling in a staircase.

[@PassiveAgressive319]

I pass the Three Bridges ROC on my daily commute and have always been curious about what goes on inside since it was built in 2014! Thanks Geoff my curiosity has been fulfilled!👏

[@teejayy2130]

That was brilliant video. It's best watched on the telly. All your videos are tv quality👍

[@geofftech2]

that's very kind of you to say, thank you!

[@davidwright9013]

I'm definitely with Chris, I simply can't get my head round how people do this job, my brain just doesn't work that way and never could! Fascinating watch :)

[@nickmiller76]

There are some jobs that need to be done by men.

[@TheDamo0313]

I work as a developer supporting some of the software used at the ROCs an had the privilege to visit the ROC in Derby. Truly an impressive experience.

[@bobseago1513]

Brilliant. Enlightening in the same way as one of Don Coffey's cab rides on a freight train.

[@dedistaulapanodki6293]

Fascinating. The juxtaposition of 19th century mechanical signalling with the 21st century monitor showing the approaching train movements is an indication of one the biggest challenges: making all the different systems work together. Working in Signals & Telecomms back in the 1980s, I was impressed how they managed to work out the immensely complicated interlocking was using just relays (thousands and thousands of the power-hungry bu**ers). And standing in one of the smaller relay rooms, you could tell as trains passed through the section controlled by it from the "chatter" of the relays moving through the room as the train triggered block sections and signals changed aspect.

[@MonkeyTennis89]

Fantastic video, as a driver it's always interesting seeing the person on the other end of the GSM-R doing their job. On my patch our final semaphores were replaced 4-5 years ago, so very happy that I had the experience of driving under this system as well as more standard TCB Colour Lights!

[@WillGrimm623]

It’s amazing how the US rail network is so much larger and yet we only have one area with mainline semaphores left in the country (rural New Mexico and Colorado where the line is down to only 2 passenger trains a day and no freight and there’s no incentive to modernize)

[@fuzzynutter8344]

Where I live, one of the stations, Worcester Shrub Hill, has a wonderful array of semaphore signals still in operation.

[@alexdreamer9950]

Another superb video Geoff. Great to have an insight into something the vast majority of us take completely for granted when travelling on a train.

[@bobseago1513]

You bring us 'tales of the unexpected' Geoff. So many absorbing rail features.

[@christophervalkoinen6358]

This is a genuinely excellent video Geoff. A fantastic introduction to the principals that keep the railway safe. Well done. Probably not intentional but great timing as NRM just put out a video on Sunday about the class 700s using ATO on Thameslink.

[@kr46428]

What an incredible inside look at Network Rail's different signaling operations. This makes me very interested in learning more about how it all works.

[@Jack-ii8vi]

Signaller here. I've trained a few signal boxes that are semaphore. Believe me, they won't go for a long long time. Absolute block works, and in places where there isn't a train in each signal section, all day, there is simply no need to upgrade to colour light.

[@chrislambert-shiels5291]

Absolute block can be used with colour lights too! As well as semaphore signals with track circuit block I think.

[@Jack-ii8vi]

@@chrislambert-shiels5291 It can! Not sure if Semaphores can be used for track circuit block however. There could be exceptions, there always is with the railway haha

[@mdhazeldine]

I know Chris would never say it on camera, but are money, reliability and central oversight not motivations for eliminating old signal boxes? Less signallers required (less salaries to pay), less hardware to maintain, less mechanical stuff to go wrong and having all signallers together in one room seems like something NR would want to push for as soon as they can justify doing it.

[@Jack-ii8vi]

@@mdhazeldine Eventually, probably. Network Rail is always looking to improve the railway. However, old signal boxes work. They do the job, perfectly. It's impossible to justify the funds for it. However, more and more signal boxes are slowly being eaten up by ROC's. The train geek within me hates it. I love working signal boxes that are on the ground, over 150 years old. However, you cannot stop modernisation.

[@chrisdenham9086]

@@mdhazeldinethe reason I didn’t say it is that the cost of resignalling schemes is so wildly improbable now that “fewer people” isn’t enough of a motivation compared to the cost (Feltham resig was £345m). Also although you lose some posts, the ones that are left are almost always higher grade. In terms of having people in the same room etc, that is definitely a thing though yes.

[@radiosnail]

I had no idea mechanical signal boxes still exist. Wonderful! THankyou!

[@mdhazeldine]

There aren't too many left and they are rapidly disappearing except on the very quiet cross country branch lines. The next lot to disappear in my area (Waterloo to Portsmouth line) are Farncombe, Haslemere and Petersfield. They'll be going within the next year. Some will be demolished and others will be turned into offices or museums.

[@richardharrold9736]

@@mdhazeldine madness. Getting rid of them is idiocy. At the very least they should be left in-situ as a fall-back for when the electronics inevitably fail.

[@nomadMik]

This isn't just one of the most interesting and well done videos you've made, Geoff, but it's one of the most interesting and well done videos on KZbin.

[@Boffin55]

I remember as a kid in the late 70s I had a distant uncle who was a signalman at Surbiton. I remember spending an hour or so in the signalbox one evening; and the (then) giant panel taht was about a 10-15 mile stretch of the South West Mail Line (and a few minor lines). I remember that the level crossings all had CCTV, and the signalmen had to turn on the flashing lights, wait for the cars to stop, then drop the gates, (all done via CCTV) then set the signal. I still look for that box (it's still there) when I whiz past..

[@ThomasJM]

I remember hearing that the hardest part about replacing the old style interlocking and signals at Union station in Toronto was developing a computer system that could handle the complexity of it. The tracks in union station are often referred to as the shortest railway with the most amount of switches. When it was built the two main railroads didn't want to build tracks to it so the city of Toronto built what ended up being called the Toronto Terminal Railway.

[@alexandraclement1456]

Wow. I believe there are still two signal boxes there.

[@ThomasJM]

@@alexandraclement1456 I think they aren't active anymore but I'm not really sure

[@alexandraclement1456]

@ThomasJM , that wouldn't surprise me.

[@ThomasJM]

@@alexandraclement1456 also don't get me started on all of the people who think Tom Sawyer island needs to go because they have never been to it and their opinion means more than the people who go to it to get away from the crowds and allow their kids to play and enjoy themselves.

[@jfmezei]

There have been similar projects in UK, but one part of Toronto union project is to redo all the interlockings and move to centralized control from the remaining signal towers. And this is sort of a pre-requisit to electrifying since electrification requires you know where each switch is. Wouldn't be surprised if they leave out the changing of switches and just electrify over existing track layouts. Go is going ETCS-2 but not sure if Toronto Union will go to ETCS or stick with lights.

[@LKBRICKS1993]

I love the old style signal box snd semaphore signslsvery interesting i love looking at old railway history.

[@fuzzylon]

Wow !!! Fantastic Video !! I have always found signalling fascinating. It's wonderful to have a close look like this.

[@jacquelineharrod6386]

Hooray for Littlehampton! A fascinating video as always. Thank you.😅

[@marksaddler]

Fascinating to see the progression and how it all works 👍

[@ianmcclavin]

I lived near Three Bridges for over 40 years. I can remember when the Rail Operations Centre and ASC didn't exist, and the main London to Brighton line, plus associated branches, had numerous smaller signal boxes along the routes. Not all corresponded to station locations, we had "Streatham Junction" (near Streatham Common Station), "Gloucester Road Junction" (just north of East Croydon, where the main lines to London Bridge and Vuctoria diverge), and "Stoat's Nest Junction" (near Purley). Three Bridges itself had its own small box, situated at the southern end of Platform 2.

[@aguyinisaan1835]

As an ex- Thameslink driver we used to call three bridges box “the snooker club” because we always had a red before getting another colour at the major stations. The amount of delays we encountered because of late running south central services was criminal, if it was booked in advance of our service we had to wait. I never understood the logic, why make another train late unnecessarily because of another late running service? The arguments between one of our senior operating managers and their train regulators were legendary!

[@cigmorfil4101]

Because of transfers? Passengers on train B want to use train C. As B is timetabled to arrive before C this is no problem, unless train B was made late by train A running late. If C is let go before B you get all the angry passengers on B who missed C, particularly when train B or C isn't very frequent.

[@scottpannell2286]

Something about a semaphore I loved. This it was knowing that there was an element of human cause and effect! I miss the huge stacks of them at Barnetby.

[@jdavis460]

I liked having the old signal boxes as you had another pair of eyes looking after their local sections. (Plus handy for hot water for the tea can)

[@tucker9162]

As a COSS I've spoken to many many signallers to get line blocks. They are the most calm and collected people on the railway and don't get the credit or pay they deserve.

[@jerry2357]

4:48 There are forms of mechanical logic that were earlier than railway mechanical interlocking, for instance the Jacquard loom, which used punched cards to weave a pattern, was patented in 1804. There were lots of different precursors to the electronic computer.

[@SamI-bv9kd]

Wow, I had no idea the old style signal boxes were still in use. Thank Geoff.

[@Cchogan]

What I like is that there is still a human involved in critical decisions about safety. It is impossible to overstate how clever the human brain is and how far away from it AI is. Sometimes, humans are simply the better choice.

[@treinenliefde]

Mwahh, I have to disagree. Here in the Netherlands we use an automated system that follows the principles of interlocking but is combined with the path a train needs to take (scheduled route, platforms, waiting time etcetera) which has since the 90s made rail traffic much safer here. Interlocking is one thing, how about having a system that can't even think about sending a train down the wrong path. Signallers are still here for delays and emergencies, but the system is much safer than a human operator can be. Logic is poweful. A train is in a section? Okay, the signal is red no matter what. A train is nearing a crossing? It will lower. For sure. Look at the video. The signallers have to manually activate crossing gates or put signals to danger. In an age where train protection systems can see trains getting in the same block and crossings can have automatic activation I can not see one good reason to keep us humans in charge of saying where a train actually is. Not on heavily used networks at least. There have been deaths in many countries, even in the 21st century here in Europe, including the UK, because of signallers missing something. That's not a risk worth having if the alternative has worked for more than 20 years. There hasn't even been one accident in the Netherlands attributed to a failure of the automatic signalling system since it's full implementation in the early 200s. Meanwhile I only have to look to Germany in 2016 where 12 people died because of a distracted signaller.

[@mattpotter8725]

@@treinenliefde I agree with you, humans are only, well human, and they do make mistakes. I do think they need oversight and people who can step in if systems fail, but to say humans are better than well designed computer systems is just rubbish (and this has nothing to do with AI, these automated systems have been there long before the current AI craze has come along).

[@EwanMarshall]

@@treinenliefde they have that on some routes there too, it is called automatic route setting (he mentioned it existed but not on the workstation they were looking at), but there is always a time for a human, what happens if the standard path is blocked and you have to route trains around it? Sometimes sending a train down the "right" path is suddenly the wrong thing to do. Quite frankly we don't need AI at all though, better to have the signalling work predictably.

[@alexfrye6]

@@treinenliefde We have all the same technologies in the UK (traffic management, automatic route setting, automatic level crossings with obstacle detection etc) but they're not applied universally, partly because of cost partly because there's no need on quieter bits of the network.

[@StephenRossiter]

Terrific video. Very enjoyable and very informative about what I was always curious about. Thank you!

[@Carlos-im3hn]

fantastic detail, discussions, and locations. Learning a great deal here and getting up to speed. I am from across the pond. Thanks Geoff !

[@BDavinci06]

This kind of reminds me of my job at the New York City subway at a smaller scale. I don't handle the signals. I actually drive the trains but to see the people at the towers in the master towers that cover a huge section of the Subway and in the Rail Control Center that covers the entire Subway system. I've seen how they work while i'm at work

[@geofftech2]

Amazing! what line do you drive ?? What’s the oldest signalling they have on the Subway?

[@BDavinci06]

@geofftech2 I'm all over, but i've operated every line in the system. The oldest I've seen in the system is Jay Street and Hoyt-Schemerhorn Streets Towers in Brooklyn. They have the old signal levers, similar to the signal boxes in the UK. They also have those old signal levers in some of the yards. Most towers have push button levers where you set an entrance and exit on the line.

[@MartinBrenner]

In Germany we also have these 3 steps of evolution of signalling. The oldest being mechanical lever frames looking a bit more massive than the British ones, the second being electromechanical with the most common one called SpDrS60 (line plan and push button signalling system) being used from 1963 and finally electronic and digital signalling like the ROC shown in the video. Very interesting to see how signalling works over there, thanks for showing us inside!

[@robnorth480]

I was lucky enough to have a tour of the Reading Signal Box back in the mid-1970s courtesy of one of the signallers, Mr Dunster, who was a friend of my grandfather. It was button and knob operation and I was allowed to operate a couple of signals.

[@Sorarse]

Having worked a number of diffrent types of signal boxes, I can hand on heart say that my favourites to work were the old one man boxes. Loved looking out the windows watching the trains and world go by. Modern centres are obviously much more efficient, certainly form a manpower point of view as they cover a much larger area, but watching a computer screen all shift wasn't my idea of fun.

[@andrewreynolds4949]

The third main reason for resignalling is for consolidation; a long stretch of railway can be easily handled by one person using modern systems, where many mechanical signal boxes did previously. Thus many structures no longer require maintenance, fewer signalers are required, and communication within the signaling area and with other areas becomes simpler.

[@physiocrat7143]

But the consolidated system is vulnerable, having lost resilience.

[@andrewreynolds4949]

@@physiocrat7143 Yet on the other hand, there are more things to go wrong when there are many manual signal boxes; it only takes something happening to one of them to block the line. It's still possible to build redundancies into a consolidated system, just more expensive than without

[@richardharrold9736]

@@andrewreynolds4949 but it's vastly less likely to go wrong than the modernised centralised electronic bullshit systems of today.

[@zedcharlie]

I was on the footplate 42yr and I never knew that was where Bobby originated. Still used by old hands and probably young hands...er maybe. 👍

[@ClaytonCarte]

Fantastic video! I love the comparison and contrast between old and new. How cool to learn some parts of the railroad still use semaphore signals.

[@IBLRG]

At Gainsborough Central, on the 1 round trip Monday to Friday Brigg Line service. Network Rail replaced all the semaphore signalling with new semaphore signalling, at a cost of £25000 per signal.

[@silverstar1964]

Best video ever Geoff, absolutely outstanding. Only surprise for me, as I'd clearly misunderstood, is that even with ETCS there are still traditional signals trackside rather than in the cab. Wonderful job by Network Rail hosting you and explaining everything so clearly.

[@geofftech2]

ah, thank you .. kind comment!

[@fruitloop3733]

There are different configurations and levels of ETCS deployment, retaining existing lamps on sticks style signalling concurrently with ETCS deployment is often used to facilitate migration when not all rolling stock is fitted with ETCS on board equipment at the time of ETCS deployment. In due course when all trains that use the ETCS area are fitted then the traditional colour light signalling can be removed.

[@court692able]

As a train driver myself it’s fascinating how big the team is that keeps me on route and gets me from A to B

[@fromabove2024]

The Severn Bridge signal box at Shrewsbury, the biggest operational one in the world will be one of the last I reckon.

[@chrisdenham9086]

Yep. You’d have to replace all the manual boxes in the area in one hit and it would be ££

[@antonydennett5938]

Thanks Geoff. A fascinating video. You don't think of those people behind the scenes setting routes etc.

[@hi-viz]

Remember anyone who's a semaphore fan visit the Cumbrian Coast line it's still a delight for them

[@aviator3926]

Thanks for covering this! I joined Network Rail in January as a Signaller and am so glad that I did. It's weird where life takes you!

[@tucker9162]

Can I have a line block please signaller? I have a GZAC 🙂

[@backwheelbob46rr]

​@@tucker9162the most hated phone call we receive 🤣

[@BarneyLeith]

Excellent and informative. Many thanks, Geoff.

[@Sim0nTrains]

Brilliantly presented Geoff. Really do love signal boxes and the old semaphore signals.

[@davidgibson1978]

Thanks Geoff for this documentary on signalling covering the first type of signalling system right through to the modern-age signalling to show how the signallers keep the trains moving safely to ensure us passengers get to our destinations safely.

[@ProfessorPesca]

Beautiful lever tops in that box, obviously looked after by the residents.

[@chrisdenham9086]

It also had the nicest signal box loo I’ve ever seen. A very well cared for box!

[@oldschoolpaul73]

Thanks. We do try to look after them. Regards, siggy in the video 🙂.

[@Scott757300]

There’s a set of semaphores near Boston in Lincolnshire and for ages I wondered why they were there, mixed in with colour signals. And it dawned on me, they were all the signals for one level crossing that is still an old fashioned style level crossing. Since that was never replaced, neither was its signals.

[@Ad-gn8pl]

Worcester area is a good shout for the last to convert. Lots of singal line which constrains capacity, lots of different systems, lots of boxes to change.

[@richardarcher3254]

This was a fascinating watch Geoff. Pity there was not enough time to examine the subject further. Let's have some more of these behind the scenes docu's.

[@Rivenworld]

Been to 3 Bridges when I was driving for Southern and an old still functional signal box at Pulborough, had a great time.

[@TerryAsh04041960]

Nice job Geoff. Good to see my local station getting some exposure for the right reasons 🙂