Author Topic: Central Office Names  (Read 9497 times)

Offline poplar1

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Re: Central Office Names--Baltimore City
« Reply #15 on: January 02, 2014, 03:24:05 PM »
Baltimore, MD changed from 2 letters+ 4 numbers to 2L 5N effective May 16, 1953:

"C'est pas une restauration, c'est une rénovation."--François Martin.

Offline poplar1

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Re: Central Office Names--Baltimore City
« Reply #16 on: January 02, 2014, 03:38:48 PM »
It seemed strange that in each case, a numeral other than 1 was added to the existing Baltimore central office name. On closer inspection, the choice of number in each case is the one corresponding to the third letter of the office name: for example, for BElmont, 5 was chosen and L on the dial would be 5. For TUxedo, 9 was chosen and X on the dial would be 9.

Only Boston, New York City, Philadelphia and Chicago actually dialed 3 letters of the phone number (PENnnsylvania xxxx,  HAYmarket xxxx). These were the only cities large enough to need the equivalent of 7-digit phone numbers. When they changed from 3 letters + 4 numerals to 2L 5N in these four cities, the third letter changed to the corresponding numeral: PENnsylvania 5000 became PEnnsylvania 6-5000. So no changes to the central offices were needed for that change.
"C'est pas une restauration, c'est une rénovation."--François Martin.

Offline tallguy58

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Re: Central Office Names
« Reply #17 on: January 02, 2014, 05:56:21 PM »
From the Montreal gazette Sept 20, 1958
Cheers........Bill

Offline poplar1

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Re: Central Office Names--Philadelphia
« Reply #18 on: December 31, 2014, 10:26:17 PM »
List of "offices" attached to the bottom of a 302. Note that AT&T called them "offices" or "central offices", and not "exchanges." Exchange referred to a geographical area,  which might contain one or many offices.

Today some refer to the "offices" as NXXs or prefixes.

« Last Edit: December 31, 2014, 10:46:51 PM by poplar1 »
"C'est pas une restauration, c'est une rénovation."--François Martin.

Offline Mr. Bones

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Re: Central Office Names
« Reply #19 on: December 31, 2014, 10:35:26 PM »
Very cool sticker, Sargeguy!

     Are the the numbers in the RH column prefixes, or area codes? They don't seem to correspond with the exchange names, at a glance. Also the first time, outside of horror movies, etc. that I've seen "666" listed! ;D

     Keep up the great work, Super Sleuth! <(Shades of Brains Benton)> 8) Happy New Year!

Best regards!
« Last Edit: December 31, 2014, 10:40:51 PM by Mr. Bones »
Sláinte!
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Offline poplar1

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Re: Central Office Names
« Reply #20 on: December 31, 2014, 10:42:53 PM »
These NNXs were probably added later, that is, after names were no longer being assigned and phone numbers were (area code +) 7 numerals. Area codes at that time always had 0 or 1 as the middle digit.
« Last Edit: December 31, 2014, 10:48:10 PM by poplar1 »
"C'est pas une restauration, c'est une rénovation."--François Martin.

Offline AE_Collector

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Re: Central Office Names
« Reply #21 on: December 31, 2014, 10:50:15 PM »
PENnsylvania 5000 became PEnnsylvania 6-5000.

Can anyone else hear The Glenn Miller Orchestra playing in the ball room of the Pennsylvania Hotel in New York?

Terry


Offline Mr. Bones

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Re: Central Office Names
« Reply #22 on: January 01, 2015, 12:35:07 AM »
PENnsylvania 5000 became PEnnsylvania 6-5000.

Can anyone else hear The Glenn Miller Orchestra playing in the ball room of the Pennsylvania Hotel in New York?

Terry
I can, literally... shot you 2 PMs, and 2 emails, to your biddlecombe@ addy, only one I have.. Enjoy!

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unbeldi

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Hotel Pennsylvania PE 6-5000
« Reply #23 on: April 19, 2016, 07:19:24 PM »
Last night, on the occasion of watching the groups Earth, Wind & Fire and Chicago at Madison Square Garden, I stopped by the Hotel Pennsylvania across the street from the Garden, and picked up a business card still showing its famous telephone number, which doesn't need to be repeated.  However, the central office name is gone.

Funny thing was that I had to ask someone to give me one, they don't just leave them sitting on the concierge's desk.

It seems the building will finally be renovated, and not torn down, as the facade of the hotel is now enclosed completely in scaffolding and screens.

The hotel's owners and fans claim that it has the longest in service telephone number in New York City, although the exact date of original service installation appears uncertain. Seven-digit telephone number were first installed in NYC in 1930, when the system was completely reorganized in a 3L-4N numbering plan. The PEnnsylvania central office was the first in NYC to be converted to a 1ESS system in 1969.

All around a nostalgic evening, I suppose.

Offline AE_Collector

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Re: Central Office Names
« Reply #24 on: April 19, 2016, 08:25:51 PM »
You would think that they would put both Pennsylvania 6-5000 as well as 736-5000 on the business card. But, I guess there are what...1 in 1000 people left who would "get it" now?

One given is that the CO was NOT SxS when that number was given out. Up 10 and in 10 on a connector switch leaves room for one and only one trunk to their PBX. SxS Trunk hunting or Trunk and Level hunting connectors led to numbers that ended in 1. Pennsylvania 6-5001 or more likely (to allow for more than 10 trunks in total) Pennsylvania 6-5011.

Terry

Offline poplar1

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Re: Central Office Names
« Reply #25 on: April 19, 2016, 08:38:12 PM »
You would think that they would put both Pennsylvania 6-5000 as well as 736-5000 on the business card. But, I guess there are what...1 in 1000 people left who would "get it" now?

One given is that the CO was NOT SxS when that number was given out. Up 10 and in 10 on a connector switch leaves room for one and only one trunk to their PBX. SxS Trunk hunting or Trunk and Level hunting connectors led to numbers that ended in 1. Pennsylvania 6-5001 or more likely (to allow for more than 10 trunks in total) Pennsylvania 6-5011.

Terry
You would think that they would put both Pennsylvania 6-5000 as well as 736-5000 on the business card. But, I guess there are what...1 in 1000 people left who would "get it" now?

One given is that the CO was NOT SxS when that number was given out. Up 10 and in 10 on a connector switch leaves room for one and only one trunk to their PBX. SxS Trunk hunting or Trunk and Level hunting connectors led to numbers that ended in 1. Pennsylvania 6-5001 or more likely (to allow for more than 10 trunks in total) Pennsylvania 6-5011.

Terry

Terry, I don't think NY City ever had any SxS, only 1XB, 5XB and ESS--though possibly DMS and others now?
"C'est pas une restauration, c'est une rénovation."--François Martin.

Offline AE_Collector

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Re: Central Office Names
« Reply #26 on: April 19, 2016, 08:47:04 PM »
Not that I have any idea at all, but I too doubt there would have been any SxS in the city. But, you left Panel off the list of old technologies. 5ESS now as well as DMS pobably.

Terry

Offline xhausted110

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Re: Central Office Names
« Reply #27 on: April 20, 2016, 12:41:23 AM »
There was no step in New York City, except for "Centrex CU" and private pbx's. PEnnslyvania 6 was panel until the installation of the #1 ESS, and is now a 5ESS.
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Offline rdelius

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Re: Central Office Names
« Reply #28 on: April 20, 2016, 09:39:59 AM »
I thought NYC had some Panel switches

unbeldi

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Re: Central Office Names
« Reply #29 on: April 20, 2016, 01:48:03 PM »
Penn6 was indeed a Panel system and so were many (most?) exchanges in the city.  Panel was AT&T's solution to high density switching in urban centers and was designed to handle manual offices well, because the big city problem was that it was impossible to convert to dial all at once.

Panel was really the beginning of common control systems, in which the subscriber's dial no longer directly controlled the switching action in the switch—that was left to the Sender units which had digit registers to store the digits for the period that the customer needed until finished dialing, and therefore the switch itself was not tied up for the entire period of dialing.

In a way, the Sender circuit eliminated the job of the operator.
The first Panel exchange was installed in 1915 in Newark, just a few miles from NYC, and Newark is a large office as well.  But being this early, the Newark system did not have the Sender yet, and operators were still needed to get the number from the customer and dial it themselves. The subscribers only had manual telephones.

Panel could also handle seven digits from the beginning, but the seventh digit was the party line letter. I think this was extended to eight digits, when the system was changed to 3L-4N (in 1930?).

As mentioned earlier, indeed, NYC also had a lot of Crossbar systems, in fact the first installation of the No. 1 Crossbar was in Brooklyn in ca. 1937.

As AT&T was apparently slow to roll out the 5ESS line, NYC has a lot of DMS systems still installed, DMS-100, DMS-10, and I think I have seen listed DMS-500 switches as well.