[HN Gopher] Telephone Exchanges in the UK
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       Telephone Exchanges in the UK
        
       Author : petecooper
       Score  : 66 points
       Date   : 2025-06-15 19:33 UTC (3 hours ago)
        
 (HTM) web link (telephone-exchanges.org.uk)
 (TXT) w3m dump (telephone-exchanges.org.uk)
        
       | biofox wrote:
       | This is an impressive feat of cataloguing!
       | 
       | 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.
        
         | rwmj wrote:
         | My physics teacher in the 1980s (sadly RIP a few years ago[1])
         | told me that the location of telephone exchanges was a UK state
         | secret. The theory was that the Russians would nuke them
         | destroying the country's ability to communicate, but as their
         | location was a secret that outcome could be prevented. 40+
         | years on, I wonder if any of that was actually true?
         | 
         | [1] https://johnchess.blogspot.com/2019/11/david-
         | welch-1945-2019...
        
           | toyg wrote:
           | The dullness is eerily consistent. Even in the age of
           | privatisation, when everything is a brand, these buildings
           | are devoid of markings. So it might well be true, we just
           | stopped worrying about it once the cold war was officially
           | over (once we realized the Russians already knew everything
           | they needed anyway).
        
           | edent wrote:
           | Sort of, yes. https://en.wikipedia.org/wiki/BT_Tower#Secrecy
        
             | biofox wrote:
             | Two more examples of exchanges that were kept secret:
             | 
             | https://en.wikipedia.org/wiki/Anchor_telephone_exchange
             | 
             | https://en.wikipedia.org/wiki/Guardian_telephone_exchange
        
           | snthd wrote:
           | >As our [1978] trial started, witness after witness from
           | security sites tried to claim that openly published
           | information was in fact secret. In a typical interchange, one
           | Sigint unit chief was shown a road sign outside his base:
           | 
           | > 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...
        
       | ipdashc wrote:
       | In a similar vein, but for the US: https://www.co-buildings.com/
       | (And a shoutout to https://long-lines.com/)
        
       | tdeck wrote:
       | If anyone is interested in telephone exchange technology at all,
       | I highly recommend checking out the Connections Museum in
       | Seattle. They have multiple eras of electromechanical switching
       | equipment up and running, and a huge collection of cool old
       | phones, teletypes and payphones. They also have a great YouTube
       | channel with very knowledgeable people.
       | 
       | 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!
        
         | evolextra wrote:
         | I know one guy who make something cool with old Telephone and
         | electronic stuff https://this-museum-is-not-obsolete.com/
        
       | jonatron wrote:
       | I visited an exchange back in 2009, when Local loop unbundling
       | (LLU) on ADSL was big, and fibre was limited to large business
       | and datacentres. The huge generator was probably more interesting
       | than the racks of concentrators. I'm not sure how much battery
       | back-up power time the new PON systems have, I assume less than a
       | generator backed system.
        
       | ricardo81 wrote:
       | Our old countries (and their tech) building on top of old.
       | 
       | 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 :-)
        
         | f4c39012 wrote:
         | someone from the local gas company told me that the reason the
         | utilites don't work together is that they can't because of
         | rules - electric and gas need to be kept separate for safety,
         | and the surrounding soil means water leaks can be absorbed away
         | from other utilities' pipework. I didn't dig any deeper
        
           | kimixa wrote:
           | I feel there's a generation of Brits burned the wave of
           | random telecoms companies digging up major roads for years
           | for cable, only for the results to be pretty much useless by
           | the time it's done as ADSL and existing POTS lines could do
           | pretty much the same thing without any more digging.
           | 
           | The words "Diamond Cable" still fill me with dread to this
           | day. They dug up half our village to then offer no service.
        
             | Affric wrote:
             | The roadworks during my youth were endless. It was
             | maddening. Never occurred to me that it could have all been
             | telcos.
        
             | JdeBP wrote:
             | I know someone who is still waiting for City Fibre, who dug
             | up xyr road last year, to get around to actually offering a
             | service.
        
           | matt-p wrote:
           | Like most things that's half true.
           | 
           | 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).
        
       | _joel wrote:
       | You can go and play with an old branch exchange, with all the
       | whistles and er, bells at "This Museum is (not) Obsolete". Run by
       | Sam from Look Mum No Computer. If you're ever near Ramsgate in
       | the UK.
       | 
       | https://this-museum-is-not-obsolete.com/
        
       | heraldgeezer wrote:
       | Really, its own internet system before the internet. Massive load
       | of calls. The routing has to be correct. I never understood it
       | before working in telecom, but phones numbers are unique... for
       | routing, like IP-addresses. And it could never go "down". In the
       | 80s it was all digial too (Ericsson switches) and had to be real-
       | time.
        
         | psychotaurusaqu wrote:
         | Combination of Ericsson and GEC/Plessey/BT "System X" (see
         | https://en.wikipedia.org/wiki/System_X_(telephony)). Erisson
         | AXE10 was known as "System Y" in the UK and a hedge against
         | buying exclusively System X equipment.
        
         | merlynkline wrote:
         | Before modern digital electronics, telephone numbers were
         | literal routes - when the turned dial on your phone ran back to
         | zero, a corresponding 10-pole motorised rotary switch at the
         | exchange turned and connected you to one of 10 lines. This
         | connected you to another such rotary switch for the next digit,
         | until eventually you were connected to the final destination.
         | The ingenious Strowger exchange.
        
       | backendEngineer wrote:
       | and it's gone... 429 :D
        
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       (page generated 2025-06-15 23:00 UTC)