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Vintage Telephony and Telecomms Vintage Telephones, Telephony and Telecomms Equipment |
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9th Sep 2018, 12:36 pm | #21 |
Nonode
Join Date: Oct 2014
Location: West Midlands, UK.
Posts: 2,181
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Re: Dialling before STD
ref #16 - thanks for that Pellseinydd. I knew of the existence of the operator's trunk network. We had access to it at one TRS I worked at and it very useful when systems went down and the STD network got congested. Sometimes knowing the routing of a group could help locate the source of the problem and get a faullt no.
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16th Sep 2018, 12:50 am | #22 |
Triode
Join Date: May 2007
Location: Northampton, UK.
Posts: 36
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Re: Dialling before STD
Actually VIF stood for Visible Index File. There's one for sale on eBay last week (https://www.ebay.co.uk/itm/vintage-G...-/263927216697) but it was empty, missing all those tasty trunk dialling codes!.
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16th Sep 2018, 9:15 pm | #23 |
Tetrode
Join Date: Aug 2018
Location: Glasgow, Scotland, UK.
Posts: 55
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Re: Dialling before STD
Just as I thought I understood this, I visited the Postal Museum and saw a few call boxes. I noticed this list of dialling codes. It appears they have 'redacted' the name of the local exchange though I assume it was to the north of London. As far as I can see, for a local number you dialled the number only (no code). How would the exchange know this was a local number? Nowadays all codes start with '0'. In earlier days of all-figure numbers I think they were '0', '8' or '9'. How did this previous system work? Did they have to find all the codes and exclude local numbers starting with the same digits, or did they take the first digit of the local numbers and make sure this was not used as the start of any code? How did this fit in with the idea of having meaningful codes?
Last edited by Scott37; 16th Sep 2018 at 9:36 pm. Reason: Comprehensibility |
17th Sep 2018, 11:48 am | #24 |
Heptode
Join Date: Jul 2007
Location: Flintshire, UK.
Posts: 707
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Re: Dialling before STD
Within the London (or any other) Director area, you dialled the first three letters of the exchange name followed by the four numeric digits - effectively it was a seven digit number with the first three letters being the routing code to the required exchange. (Don't worry about how it was achieved). Hence you still dialled the first three letters to indicate it was an 'own exchange' call. To reach exchanges outside the Director area but within the local call charge area, you dialled a local code of letters/digits to reach the required exchange. The length of the local codes varied such that the total number of digits required was seven (same length as the 'Director' exchange numbers'. Outside the Director areas, you just dialled the number on your own exchange (or another exchange in a 'Linked Numbering Scheme' where the first digit/s indicate the required exchange) . For other local exchanges you would dial between one and seven digits to reach the other exchange in the local call area. With the coming of STD, the number of digits in the code for a local call was reduced. STD codes could be used for a local call and charged at the local rate as is done these days. To think it is nearly a quarter of a century since local dialling codes ended. However we still have them 'preserved' on CNet, our replica of the old GPO UK phone network as it was back in the days before the coming of 'Linked Numbering Schemes. I can reach 'Chester' numbers by dialling the old local code 91 or I can dial 0244 - makes no different except that with the STD code can't dial Chester numbers beginning with a 9 or 0 after the 0244 - just as it was in the good old days. Interesting that we now have subs numbers beginning with 9 so that rule has obviously gone!
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17th Sep 2018, 12:08 pm | #25 | |
Heptode
Join Date: Jul 2007
Location: Flintshire, UK.
Posts: 707
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Re: Dialling before STD
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17th Sep 2018, 1:09 pm | #26 |
Tetrode
Join Date: Aug 2018
Location: Glasgow, Scotland, UK.
Posts: 55
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Re: Dialling before STD
Thanks for the replies. I'm still a bit puzzled. I assumed the notice was for a non-Director exchange, with the name of the exchange blanked out. Should the missing space read 'London'? This still leaves the question of what would happen in a non-Director exchange. How would the system know that a local number was indeed a local number and not one of the local codes; and that a code was not the start of a local number? Was there one reserved digit for the local numbers?
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17th Sep 2018, 4:16 pm | #27 |
Heptode
Join Date: Apr 2011
Location: Edinburgh, UK.
Posts: 805
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Re: Dialling before STD
Yes.
Either there was a Linked Numbering Scheme, or there were local codes. In a Linked Numbering Scheme the parent exchange would have numbers starting eg 7xxxx. Satellite exchanges would have numbers starting 81xxxx, 82xxxx, 83xxxx etc. Dialling from a satellite exchange the exchange would recognise what was an own-exchange call and drop the first two digits, and calls for another satellite exchange would route to the parent exchange by the 8, then the outgoing junction circuit 1, 2, 3 etc. Subscribers on the parent exchange had direct access to the junctions by dialling 81, 82, 83 etc. With exchanges not in Linked Numbering Scheme, there were local codes, usually starting 9 (or sometimes 8). Eg 9 for the parent exchange then 8081 for the Speaking Clock. This lead to local codes like 981 from B to A, but A to B would be 81. C to B might be 9812 etc. Basically with local codes you had to dial the digits that controlled the actual routing of the call over the junction circuits. In the Director system the director part of the exchange took the exchange code (ABBey etc) and translated it into the digits required to route the call even if that was through two or three tandem (intermediate) exhcanges). |
17th Sep 2018, 4:49 pm | #28 | |
Heptode
Join Date: Jul 2007
Location: Flintshire, UK.
Posts: 707
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Re: Dialling before STD
Quote:
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17th Sep 2018, 4:58 pm | #29 |
Tetrode
Join Date: Aug 2018
Location: Glasgow, Scotland, UK.
Posts: 55
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Re: Dialling before STD
Thanks, but I think you may be referring to a later era. The list I posted shows codes which - after converting letters to numbers - start with all sorts of digits. Could it be that this list applies only to Director areas? If so, did other exchanges have lettered local codes? How did the system distinguish between code starts and number starts?
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17th Sep 2018, 5:12 pm | #30 | |
Heptode
Join Date: Jul 2007
Location: Flintshire, UK.
Posts: 707
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Re: Dialling before STD
Quote:
Around that time, London had 'sectorisation' were the exchange names were done away with and the first three letters (or their numeric equivalent) replaced with a different three digits - thus WHI (944) became 930. All helps to confuse the issue |
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17th Sep 2018, 5:25 pm | #31 |
Tetrode
Join Date: Aug 2018
Location: Glasgow, Scotland, UK.
Posts: 55
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Re: Dialling before STD
Thanks, Pellseinydd, but I am actually more confused! (1) Leaving aside Director areas (which I think I understand thanks to your explanation), in the other areas if lettered codes were used how did the system distinguish between the numerical equivalent of the lettered code and a local number? I am sure you did not have to dial your own code at that time. (2) For London, were all exchanges sectorised or just the new ones. I lived in 274, which translates to BRIxton. I worked in 432, which translates to HEAdquarters and I'm sure I remember others that were direct equivalents. I know Glasgow is sectorised. All ours are 3xx, city centre 2xx etc. Ours used to be WEStern so clearly the numbers do not correspond to the letters any more. I hope others are as intrigued as I am.
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17th Sep 2018, 5:30 pm | #32 | |
Heptode
Join Date: Jul 2007
Location: Flintshire, UK.
Posts: 707
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Re: Dialling before STD
Quote:
Don't look to deeply as in later years, the local code from London DA to 'Lea Valley' exchange on the east side of London was '9' (Lea Valley had six digit numbers) but at the same time, the local code from the LDA to Walton-on-Thames on the opposite side of London was '98' or to Redhill in Surrey was '91' . It was all handled by the Director which looked up the digits dialled and translated them into the digits actually required to be sent to set the call up. |
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17th Sep 2018, 5:43 pm | #33 |
Tetrode
Join Date: Aug 2018
Location: Glasgow, Scotland, UK.
Posts: 55
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Re: Dialling before STD
Thanks, Pellseinydd. I think our posts may have crossed. I hope I understand the situation in the Director area. My latest - and I hope final - question is what coding system was used elsewhere and how were the local numbers distinguished from the codes.
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17th Sep 2018, 9:29 pm | #34 |
Tetrode
Join Date: Aug 2018
Location: Glasgow, Scotland, UK.
Posts: 55
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Re: Dialling before STD
I think I have answered my own question now The lettered codes were only used in Director areas (where they were co-ordinated with exchange names to avoid conflicts). Outside the Director areas the codes were numerical with different starting digits to the local numbers (usually 8 or 9). I hope this is correct
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18th Sep 2018, 12:10 pm | #35 |
Tetrode
Join Date: Aug 2018
Location: Glasgow, Scotland, UK.
Posts: 55
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Re: Dialling before STD
Thanks for everyone's contributions to this thread. I feel better informed now. I see we got an encouragingly large number of views
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