Telephone Exchanges in the UK
telephone-exchanges.org.uk
telephone-exchanges.org.uk
https://www.telcomhistory.org/ConnectionsSeattle.html
https://m.youtube.com/@ConnectionsMuseum
I feel like they're not well known and there's no place like it!
It has some old working telephone and teletype systems. You can watch the physical switching equipment do its magic. It is truly awesome. The raw speed and accuracy of the mechanical systems is almost unbelievable.
We're opening a second location like the first in Denver, to take over the hard-to-visit one in the corporate head office.
We would deliver the donuts to the break room which usually had at least one guy smoking in it (it was the '70s). A couple of times we went into the switching room which still had rotary dial switches clacking away as people dialed in numbers. There was an overwhelming smell of ozone in the room. It was all very cool to 5 year old me.
Considering the telecom system is at the bedrock of almost all modern technologies, it really doesn't get enough love or attention in the public mind.
The dull derelict-looking, and often graffitied, buildings that house the system doesn't reflect just how cool the infrastructure is.
[1] https://johnchess.blogspot.com/2019/11/david-welch-1945-2019...
Of course, nuclear weapons wouldn't even have had to specifically target exchanges in order to disrupt electronic communications as they already were by the 1980s.
It was amusing to learn a decade ago that the U.S.S.R. military had far more complete maps of many parts of the U.K. than Ordnance Survey published. Apparently down to Soviet spies just walking around a bit, playing tourist.
Although amusing, note that its than the Ordnance Survey published. I.E. they had the data, it was just classified. Also, it's fairly clear that the Soviet maps were mostly derived from OS maps. Looking at my street, for example, they have it in a pre-WWII configuration which they could only have got by starting from a rather old OS map. So they clearly only checked for differences in areas they thought important, such as government or military areas - they didn't have people mapping the whole UK. Still it's probably true that one can get more information about certain areas in these Soviet maps than in extant OS maps.
I found myself wondering whether the locations of electricty substations powering critical infrastructure might count as "secret", for instance the three[0] substations that power Heathrow Airport.
Obviously one of them isn't secret any more more, having gone up in flames rather spectacularly on 21 March 2025.
[0] "Heathrow relies on three electricity substations" https://www.bbc.com/news/articles/c6283577llqo
> Q: Is that the name of your unit?
> A: I cannot answer that question, that is a secret.
> Q: Is that the board which passers-by on the main road see outside your unit’s base?
> A: Yes.
> Q: Read it out to the jury, please.
> A: I cannot do that. It is a secret.
>Official panic set in. The foreign secretary who GCHQ had bullied into having us accused of spying wrote that “almost any accommodation is to be preferred” to allowing our trial to continue. A Ministry of Defense report in September 1978, now released, disclosed that the “prosecuting counsel has come to the view that there have been so many published references to the information Campbell has acquired and the conclusions he has drawn from it that the chances of success with [the collection charge] are not good.”
>My lawyer overheard the exasperated prosecutor saying that he would allow the government to continue with the espionage charge against me “over [his] dead body.” The judge, a no-nonsense Welsh lawyer, was also fed up with the secrecy pantomime. He demanded the government scrap the espionage charges. They did.
GCHQ and Me, My Life Unmasking British Eavesdroppers -- Duncan Campbell
https://theintercept.com/2015/08/03/life-unmasking-british-e...
https://avoncroft.org.uk/avoncrofts-work/special-collections
Developing countries have less of a hassle with implementing something based on state of the art.
Lots of hassles with getting new phone lines, new power lines et al in the UK based on old agreements and a nationalised infrastructure. Please stop digging up roads and everything for arbitrary telecoms companies based on some deregulation, some collaboration please :-)
It's true you don't want a telecom worker laying a gas pipe, however you can coordinate this stuff if you want to. Typically the deepest utility works first then backfills just to the level of the next utility and so forth. However timing is critical, the second utility must be ready to work as soon as the first is done and so on.
The biggest reasons they don't is mostly (in this order)
-They can't time their work to be at the same time as 3 other utilities.
-They can't work out cost and liability sharing, if the last utility to work does the reinstatement and takes liability for it then the telecom company will always pay while electric typically won't pay anything as it's in the middle. The legal demarcation between utilities is also much less clearly defined.
-Contractors typically do all work, not actual utilities and it's in their best interests to dig the road up five times (one for each utility) rather than just once. The same goes for everyone else who gets paid when the road is opened; including, often, the local government (for permits).
The words "Diamond Cable" still fill me with dread to this day. They dug up half our village to then offer no service.
I’ve heard other similar stories from friends in the city too.
It’s almost like there’s money for the infrastructure but not for the staff required to actually run it as a service…
Smells like they "installed" fibre in York to meet a contract/regulation but they really focus on Urban density. Makes sense for them but not for the rest of us.
I did that tour around the same time and it was fascinating ! right in the middle of the 21CN (ethernet core network) transition.
I think this probably coincides with the time period we got ISDN, very early, and I was amazed by the concept of _always connected_ internet. I can still vividly remember watching GoZilla download a game demo at 7kb/s, stunned and excited.
https://miltonkeynesmuseum.org.uk/collections/view-our-colle...
It's really surprising to me how little uptake 2600 ultimately ended up having.
There were also specialist circuits (e.g. EPS) where you had a physical line from end to end (with a couple of amps along the way on longer runs).
We also had some large campus type sites where we would sometimes implement EPS to do LAN extension over the onsite twisted pair as it was cheaper than installing fibre and just about fast enough.
"Strowger, an undertaker, was motivated to invent an automatic telephone exchange after becoming convinced that the manual telephone exchange operators were deliberately interfering with his calls, leading to loss of business."
I wonder if the phone company was actually out to get him!
There's a great video from Connections Museum (mentioned further up the thread) where they're going through the operation of, I want to say, one of those crossbar switches? And they start using terminology like "routing table", "longest-prefix matching", and "default route", which all sounds well and good, until you realize they're talking about systems that existed decades before the Internet or even ARPANET, all electromechanical... Dope stuff. Cool to see how things rhyme even as they change.
It certainly wasn't a voting system. Rather, it was a decent enough system used to help gauge demand in a given area. (Unsurprisingly, there was a lot of demand for ADSL in university towns, and much less in retirement-town-by-the-sea).
Is their content really so sensitive that it must be "protected" to such a degree?