HistoryPhotoscross-posted from: https://lemmy.zip/post/61694982
I am back!
I remember there was a few requests about more control rooms when I started posting here last time, so I thought I might honor the request even if it doesn't show much of the room part...
Anyway, this is the fully automated control panel for the rail yard at Uppsala Centralstation in Uppsala, this photo was taken on 1938/05/11 and published in the local paper, Uppsala Nya Tidning, the day after.
This machine controls the switches and signals of the rail yard at the station, a similar model can be found operational and in use at the local heritage railroad.
Sadly I don't know what the indicators mean, or how to operate it, I just think it is cool!
This photo was taken by Paul Sandberg, and is in the public domain.
From looking at this picture and what I could find online, this isn't automated (and at least everywhere else in the world, the technology wasn't that far yet). What was different with this control system was that the interlocking* system was no longer mechanical, but electric (at least according to the info I could find online). Which I find quite interesting, since this system looks very similar to the German , where the actual interlocking process happens mechanically, but the switches are set electrically.
*In railroading, an interlocking ensures that no two signals are set to green at the same time that would send trains on conflicting routes, and secures the individual trains' path against switches being set under a train.
According to the source where I found the picture it was labeled as automated.
It didn't add much information in the article, which is problem with Digitalt Museum, so I am trying to extrapolate from my own knowledge and what I can find while writing the post.
I am always open to be corrected (just be respectful about it), I mostly start searching for a word and try to find interesting photos that are licensed as Creative Commons or in the public domain. Then I try to add some context.
I make 99% of the posts from my phone, and my research may be limited, but I absolutely love to spark a conversation and uncover more information.
Wow, that was a tangent, once I started typing, I felt that I should make a comment I can link to if needed in the future.
I honestly don't know 100% either (which is why I left it open a bit), I'm mostly judging by what I could find, by what technology was typical at the time and by what seems to be the switch handles.
Do you have a link to the source? I'd be curious to see what they write about it.
Here you go, beware it is in Swedish:
https://digitaltmuseum.se/011013994595/det-nyinvigda-helautomatiska-stallverket-pa-bangarden-uppsala-maj-1938
It litterarly just says:
The newly inaugurated fully automatic control system at the rail yard, Uppsala, May 1938
Automation in Uppsala? The Unseen will not be pleased.
~(The TTRPG Vaesen is set in Uppsala and focuses on conflict between fantasy and industry)~
I found another picture where you can see the size of it as well as the backboard:
Oh, that kind of switchboard. I wonder what error rate there was in the overall system?
Welcome back!
Hmm, the nearby guy kind of looks like the original "Q" from the James Bond movies.
In normal operation, this machine has proper working electro-mechanical interlocks to prevent errors.
It is quite interesting to read about how railway systems worked in the past.
One of the first safety systems created to prevent train crashes was super simple, it was a token system, and worked just as you imagine, to be allowed to enter a stretch of track between two stations, the driver had to be carrying a token, there was only one token for that part, and it was handed in at the next station.
This meant that as long as the rules were followed there could only be one train on that piece of track, and traffic could only alternate.
Simple and safe, but inefficient.
Control of track switches are critical to keeping a railway line safe, depending on the setting of the switch, it will not only risk a head on collision, but also a derailment and other issues.
Most switches on a train line these days are remote controlled from an operations center, but there are switches that are controlled by mechanical keys, usually at a remote rail yard that only sees quite limited traffic.
These systems can be quite fun, the driver is issued a key to the first switch, he gets to the switch on the line, stops the train, gets out, unlocks the switch with his key and sets it to the new direction, that unlocks two more keys in the switch which he turns and removes, this locks the first switch.
These keys unlocks further switches in the train yard in a similar manner.
Once he has got his train to it's position, he uncouple the locomotive and goes back the way he came, resetting the keys and switches.
Once he has thrown the last switch and got the key out, he can be certain that everything is properly locked up, and can radio the control center that he is done and everything is safe again.
In fact, at least in the older technology, there are two aspects to the safety system.
The one is the safety between stations. The token you describe was one of the earlier systems (which is still used in some places around the world). That was eventually superseded by a "line block". Only one signal leading to that line can be set to green at a time, and once that signal has been set to green, no further green signal can point towards that line until the whole process is reset. After the train has passed the signal, the signal can be reset to red, and station A's rail traffic controller (RTC) then sends an electric signal to station C, which marks the line between the two, or the block, as occupied. When the train has arrived in station C, that station's RTC sends a signal back to station A, which marks the block as free. Only then is the process reset and another signal can send a train onto that line. Essentially, the token was turned into an electric signal, and a mechanical system to ensure that token was respected was added. Eventually, they needed to increase the density of the trains on the line, so they added signals on the line, controlled by signal towers. Instead of the electric signal going from station A to station C, it went to signal tower B. As soon as the train fully passes signal tower B and is protected by its signal, the signal tower agent marks the block to station A as free, and the next train can be sent on its way before the first train has arrived at station C. The first such systems actually had small generators to create that signal which were hand cranked by the RTC or the signal tower agent.
The other aspect is more the focus of this picture - the safety within stations. It essentially ensures three things: that the route is set correctly, that that route is protected from other rolling stock movements, and that the signal shows the correct speed information (i.e. it doesn't tell the driver to go full speed over a diverging switch). A later addition was to ensure that the route is free of any rolling stock, which would come a number of years after this picture had been taken. While the train is on the route, it ensures that no switches are set underneath the train, and that the train is protected from any trains that might be behind it (through stop signals). The worked with a set of keys, similar to the way you described, except the RTC would run out with the keys to the switches, set those switches, run back with the keys they got from those switches in their new positions, stick those keys into the interlocking system, unlock the key to the signal, and run out to set that signal. Later systems had the switches controlled more centrally by levers attached to either rods or wire and pulley systems, and the ability to use those levers were/are controlled by somewhat complex systems, which can often be (this is a more simple example, there are much more complex examples in larger stations). So if as a RTC you're not sure why a switch won't set, for instance, you can just look at that interlocking system, follow the rod to the path it controls, and now you know why your switch won't set. Mind you, this should only happen when you're learning that interlocking, it should not be necessary for experienced controllers, unless there's a problem. (Fun fact: in Germany, there's always a sheet of glass protecting it, and if that glass breaks, the speed is restricted to 50 km/h since the interlocking system cannot be relied on/can be tampered with. It's a running gag among RTC's as to why the glass covering the interlocking, which is at about the height of the surface of a bench, broke...)
And the thing is, for the most part, even the most modern interlocking technology is based on these principles. In fact, when you learn to become an RTC, often you will train on the older systems (which, to be honest, is a hell of a lot of fun), and most indicators in modern systems will be some equivalent of some function in the old interlocking systems, which really helps to visualize what's going on when the system has some kind of a problem.
Thank you for the detailed write up, I am not educated in rail, I am an IT guy, but my dad spent his career selling railroad signal systems, and plenty of (scattered) knowledge has entered my mind over the years.
It is always nice to find someone else knowing more than I do to fill in the blanks.
Have a lovely evening!
Thanks, same to you!
Always great to see when people are interested in the field of railroading.
That's rather fascinating. Thank you for taking the time to write it all up. 🙂
It also reminds just a tiny bit of the Apollo moon missions, which I often listen to the audio of. They made a special point of training astronauts to think externally, not the natural process of doing so internally. That involved lots of verbal checklists, communicating extensively with each other and Mission Control over whether something had been attended to. Even stuff that they barely had any real interaction with, such as the Cosmic Ray Detector panels.
In fact, in Japan, they have what they call "point and tell". Essentially, every signal drivers see, they point at it and say what it tells them, for instance, "proceed at max 50 km/h". It does quite a bit to increase safety, because it forces you to consciously acknowledge safety relevant points.
