Dialling before STD
 

Another arcane question from me: I assume pre-STD only local calls could be dialled and all non-local calls would require intervention by the operator. I assume too that if you lived in a 'Director' area you could dial local calls to the entire area (except for any remaining manual exchanges, of course). What happened if you lived adjacent to a Director area, say London, such that the calls to the Director area would be local calls. Could you dial them and if so, how, as the '01' code was not created until STD started?

Re: Dialling before STD
 

In a Director area, automatic exchanges could dial subs on all other automatic exchanges in the 'Director' area plus that could dial the manual exchanges within the area.

In the London area, they even dialled the full number of the 'wanted' subscriber on manual exchanges and the dialled number was displayed to the operator who connected the call without intervening. To call exchanges outside of the 'Director' area, but within the local call area, a code was dialled - see attached list from the instruction notice in a A/B box kiosk - sorry it is a poor copy but original is 'grim'

If you lived in an area served by an automatic exchange where the London Director area was a local call, you would dial a code - usually '7' followed by the seven digit Director rea number - see attached dialling code cards. Same applied before and after introduction of STD.

In the Manchester area, see attached dialling code card for Milnrow where the code was '9' followed by the Director area seven digit number.

However the 'single digit; system didn't apply everywhere. See attached Chester dialling code card for just before STD was introduced in Chester. All the Liverpool Director area exchanges had their own code - for instance ELLesmer Port was 96. But once STD was introduced, the STD code was used but charged at the local rate.

Ian J

Re: Dialling before STD
 

And for Glasgow - the local codes from the Director area

Re: Dialling before STD
 

Thank you for the comprehensive reply. I have been curious about this since I worked in London in 1978. One final query: could the same exchange name be used in more than one director area (eg CENtral or WEStern)? Reason I ask is: when making a trunk call into a director area, was it necessary to tell the operator the city name (Glasgow, Western or Western in Glasgow) or just exchange and number?

Re: Dialling before STD
 

There was a 'GPO' in all Director areas, and CENtral, KELvin, NORth, ROYal, VICtoria, WEstern, plus others that came & went over the years appeared in two or more Director areas.

Re: Dialling before STD
 

What was the 'approved' way of asking the operator for one of these numbers then?

Re: Dialling before STD
 

As far as I can remember you would say to the operator the city first, followed by the exchange name, followed by the 4 figured subscribers number eg- London, Whitehall, xxxx. Before all figure dialling, if you lived in a director area and wanted to call another director area which would be a long distant or trunk call you would dial TRU for the long distant operator.

Alan.

Re: Dialling before STD
 

Interesting you mention long distance or trunk call. This leads to another source of puzzlement on my part. What was the difference between a toll call and a trunk call? I believe in London you dialled TOL for the toll operator or 0 for trunk calls. I tried to research this a couple of times and as much as I could understand was that toll calls seemed to be a shorter distance (50 miles/Brighton?) than trunk calls and required a different operator. What was the purpose of this distinction and was it understood by the public? I certainly can't understand it now !!!

Re: Dialling before STD
 

Something to do with the three different charging bands of the day? ISTR "local", "a" and "b" trunk rates.

Whether this had anything to do with how far you could talk on an unamplified circuit, I don't know!

Re: Dialling before STD
 

Toll calls were connected on demand, trunk calls were booked and the operator rung you back.

Due to increasing demands for trunk calls from London and the associated delays in connecting them, calls to exchanges adjacent to the London director area were transferred to a new Toll exchange opened on 17 September 1921. Calls to toll area exchanges were connected on-demand whilst the originating subscriber waited thus improving service and reducing operator costs.

The London Toll Area boundary was extended in 1923 and again in 1928, so that eventually Southampton, Portsmouth, Reading, Bedford, Colchester and the whole of Kent and Sussex were included. The system was later introduced to other large cities and remained in use until the late 1950s when, with the advent of Subscriber Trunk Dialling (STD), Toll was eventually phased out.

In the London telephone area, calls to subscribers who were not serviced by Director telephone systems within local call-charging range of the London Director exchange area were carried by tandem exchange Toll A: a subscriber would dial a prefix code, typically two letters plus zero, one or two figures (e.g. DA, EP5, LK85) followed by the number of the other subscriber on the fringe non-director exchange. To avoid confusion, three-letter dialling codes were not used for calls from the director area to the fringe area, even if they corresponded to the same holes in the dial (e.g. the Hoddesdon and Mogador codes were HO3 and MO4 respectively).

https://www.btplc.com/Thegroup/BTsHi...o1968/1921.htm
and
https://en.wikipedia.org/wiki/Trunk_...toll_telephony

Re: Dialling before STD
 

Thanks for that, but what was the point of trunk calls if this meant 'double handling' by the operator in speaking to the caller, placing the call then calling back the caller then connecting the parties? Why did she/he not just tell the caller to 'hold the line' as presumably happened with toll calls?

Re: Dialling before STD
 

Before the trunk network was 'mechanised' (automated) and that was before STD could even happen, the trunk operator had to call each exchange along the route to get the call set up. This took time and because there might not be sufficient circuits on part of the route, it would be set up when a circuit became available. The availability of circuits was why calls were restricted to three minutes at a time and the pips came on to indicate your time was up in a coinbox. Before co-axial cables and later methods of increasing the number of circuits between locations they were very limited in number. Even in 1995 some rural exchanges only had five circuits to the main exchange/rest of the network! But as co-ax and carrier systems appeared more circuits were installed at a lot less cost. .

I looked after a large manual board for some years that was a major hub in a government network that at that time had no automation and any calls involving a switchboard that wasn't directly connected to ours (we had about 200 circuits to other switchboards) was 'booked' in the same way the GPO Trunk operator used to, and the caller was called back once the call was set-up.. All these long distance calls were restricted to 6 minutes and the caller reminded of the fact.

Re: Dialling before STD
 

And 'c' and later 'b1' rates at various time during STD calling. Calls being charges between 'charge groups'

Pre-STD the letters didn't exist. Calls were charged by distance between exchanges within radius bands - see attached map giving the rates from London.

I don't think it had anything to do with 'amplified/non-amplified'

Re: Dialling before STD
 

Thanks again, Pellseinydd for the elucidation. Why was this different to the procedure for toll calls? Were they automated to the extent that the operator could dial the distant number even if the caller could not? Or did toll calls have no intermediate exchanges, making it easy to obtain a connection? When you say that calls were limited to three minutes at a time, I remember the pips and having to pay again but I assumed if you paid up you remained connected. Are you saying the operator would terminate your call if someone else was waiting? Was it only London that had toll calls, or all director areas, or all exchanges?

Re: Dialling before STD
 

I'll answer #1 with another question. When did the operator direct routes come into existence? Before STD became fully into effect there was a set of routes for direct dialing solely for the use of operators with a set of differing codes. I first heard of it when some engineers at Stone ( Yarmfield college as it's known these days AFAIK) used this to phone home for free and were caught.
From memory of the heady days in a TRS, I seem to remember that there were set levels depending on the grade of the junction. I seem to remember that the worst case was -4dB overall loss( sent at 0dBm and received at other end receiver at -4dBm , approx half power/or voltage if you prefer)

Re: Dialling before STD
 

Answer to question at beginning - back in the 1800's once two exchanges were interconnected ;)

There had been a separate network for the trunk circuits since 1896 when the trunk circuits of the National Telephone Company were 'nationalised' and the running of the trunk network became the GPO's responsibility. Thus from then on, the National Telephone Co only handled local calls until the GPO took it over on 1st Jan 1912.

The telephone network expanded but some exchanges as late as 1955 only had two trunks to their parent exchange - Glenmoriston for instance only had two junctions to Fort Augustus although there were twenty subs on the exchange at the time. A trunk call would involve the Glenmoriston operator connecting the caller to Fort Augustus operator who would connect the call to the main manual switchboard at Inverness which handled trunk calls. the Inverness 'trunk' operator would then set the call up 'down the line to each manual exchange in turn. That all took time. Hence most long distance calls were worked on the 'delayed' system were the caller was rung back once the call had been set up.

About 1951/2 saw the start of 'Trunk Mechanisation' - the conversion of the trunk telephone network to automatic working. This was a separate network accessible only by the operator from manual exchanges or the 'auto-manual' boards at that was reached by dialling 0 (or 01 on some exchanges) and from the TOL/TRUnk manual switchboards in London, Birmingham and Manchester Director areas..

The automatic trunk network consisted of 'Zone centres (each had direct routes to all other twenty odd zone centres), Each zone centre then had direct routes to all the Group Switching Centres in its area. Each GSC had direct routes to the Minor exchanges in its area. And the there were 'Dependent' exchanges off some Minor exchanges. all the way to the wanted subscriber Assuming all the GSCs, minor and dependent exchanges were automatic, an originating operator could dial all the way! The GSCs, Minor and Dependent exchanges were part of the local network. Once STD started, dependent exchanges were connected directly to the Group Switching Centre. Whilst dialling from the Trunk network was normal, dialling from the local network to the Trunk network wasn't permitted. However very occasionally, there were errors in the trunking of circuits - for instance when Mold exchange went automatic, a level '1x' route was left 'open' allowing access into the trunk network by 'ordinary/coinbox lines. In other places, 'naughty' engineers set up their own level which didn't meter the calls and gave NU tone if dialled but you just carried on dialling. I have heard of this happening in the Bristol area and it being followed by a court case - engineers involved were sent packing .

However it wasn't a case of just dialling the 'access code' and then the STD code. The codes on the trunk network were different from each location (the operators had them listed in a VIF (Visual Indication File - a flip up card setup) so knew what to dial. Once STD appeared, the STD codes were the same all over the UK to an exchange but the local 'register translator' converted it to the required trunk network code from the originating GSC as it accessed the trunk network.

The audio levels between zone centres was certainly 0db loss, between Zone centre and GSC was 3db and to Minor exchange from GSC was 3 dB also giving a maximum of 12db - I'll see if I can find the info.

Re: Dialling before STD
 

Operators often had a choice of routes listed in their VIF, and in some cases would use unorthodox or unofficial routes to get a call through - this was particularly so in wartime when lines were damaged and military calls had to get through.

Re: Dialling before STD
 

Only Birmingham and Manchester ever got a TOL 'exchange' facility. The BT website is a bit optimistic! Their information isn't always correct :(

Bear in mind as well, that the 'TOL' facility was only a separate manual switchboard that could set the 'shorter distance' 'trunk' calls up on demand - it wasn't a system where subscribers could dial their own calls. In London, it should not be confused with Toll A and Toll B automatic exchanges that opened after WW2 to allow London Director area subscribers to dial a code to reach lines on exchanges just outside the Director area for which the charge was that of a 'local' call. The exchanges reached by dialling 'TOL' then connected by the TOL operator, were outside the local call area. I remember visiting Toll A and Toll B late one Friday afternoon and helping myself to various 'interesting' relay sets - there were quite a few 'Outgoing to CB exchange' ones from the routes to manual exchanges just outside the London Director area. Good job BT had provided me with a Transit & driver to get them all back up North! What a day out.

The 'local' charge calls to outside of a Director area nearly always ended up with 7 digits being dialled to keep the 'Directors' happy with their translation. Thus if calling say a UAX13 with three digit numbers the code would be four digits long - see Tanworth-in-Arden on attached Birmingham Director Area code card. Likewise, Coventry, Cradely Heath, Dudley & Wolverhampton (and one or two others) had five digit numbers hence two digit codes. Where an exchange had numbers of different lengths, each 'length' had a different code but for the same exchange!

Bear in mind that things were forever changing so there would end up being exceptions.

Re: Dialling before STD
 

Even in the late 1980's, if you needed to make a call to Australia you had to pre-book a time, and then get the operator to connect the call. That was the time my father in law emigrated, and it was a royal pita to phone up.

Re: Dialling before STD
 

Ian,
Perhaps you could comment on something I remember.

My sister-in-law lives 100m away from me, but was (maybe still is) on a different exchange to me.
Pre mechanisation I think it was crossbar. It was a little slow returning dial tone when you seized the line, and just before it timed out there was a loud beep.

if you continued to listen, through the silence you could faintly hear the voices of people, often children, who has presumably done the same thing. If you shouted loudly enough you could engage them in conversation. They were often some distance away.
Her number was 0161 798 XXXX The Prestwich (MRPRE) exchange is only half a km away but her line appears to be connected to a more distant exchange.