July 11th in History: 1948 Media PA #5XB, 1965 FL 305/904 NPA Split [telecom]

I had mentioned in previous postings about how this year, 2010, is the

45th Anniversary of the very first #1ESS switch being cut-in to full public PSTN/NANP service (as opposed to "experimental only", i.e., the Morris IL ECO of 1960-62) at Succasunna NJ on Sunday 30-May-1965, and I had also mentioned that the Florida 305/904 Area Code Split took effect as a FLASH-CUT also that year, on Sunday 11-July-1965 at 2:01am EDT.

And I had also mentioned the fact that calendar year 2010 is identical to calendar year 1965 as far as how the dates fall on particular days-of-the-week. This year, 2010, follows 1965, in that 30-May and

11-July are both Sundays, in both years.

ALSO, 2010 is the 62nd Anniversary of the very first #5XB switch being cut-in to full public PSTN/NANP service (as opposed to experimental "only"), also on Sunday 11-July-1948. Note that both the 305/904 Florida NPA Split and the first #5XB being cut-in at Media PA both happened on July 11th in their respective years, and both were on a Sunday, so even

1948 has the same day-of-week "mapping" as does 1965 and 2010.

Regarding the first #1ESS in Succasunna NJ, I had mentioned in my earlier posting that I was unsure if it replaced a SXS office or a #5XB office. I tend to think that it replaced an earlier Step-by-Step (SXS) office. I did some digging up of info from google searches, and there was a reference that AT&T/WECO/Labs worked with NJ Bell for the cut-in of this very first #1ESS to be installed in a town that had been served by a (roughly) 4000-line SXS switch. And since the first #5XB office in Media PA was only installed 17 years ago, I doubt that anything less than 17 years old (i.e., a #5XB) would have been in service at Succasunna NJ, only to be pulled from service to be replaced with the very first #1ESS.

As for the #5XB in Media PA, a suburb of Philadelphia PA, it is likely that it replaced a previously existing common-battery manual central office. The suburbs of Philadelphia had mostly been manual -- Panel had NOT yet extended into those suburbs. The first #1XB office was only ten years old, first being installed in Brooklyn NY in 1938. It seems unlikely that AT&T/Western/Labs and Bell of Pennsylvania would have pulled a #1XB that was only ten years old to replace it with the first #5XB office...

Englewood/Teaneck NJ was able to dial their calls to Media PA as part of the Philadelphia PA Metro area (215) with the first public use of (limited) DDD (Direct Distance Dialing) effective November 1951, even though it would be another 2-3 years before AT&T/Bell would actually begin referring to customer "nationwide" long distance dialing as "DDD". The 1951 customer instruction booklet only lists the TOWN name of Media under Philadelphia and vicinity. It does NOT indicate the particular NNX code -- or rather 2L EXchange NAme (plus 3rd-digit) for Media PA, which would probably have been "LOwell 6-" (see below).

The "ratecenter" name for Media PA is officially known as "Philadelphia Suburban Zone #12". The c.o.switch eventually had MEDIPAMEMG0 for its CLLI code, the -MG(x) extension for "Marker Group", which was the code extension used for Crossbar offices providing "local" end-office services or functions.

It appears that the #5XB was still in service at Media PA as late as

1985. By 1990/91, Media PA was being served by a #5ESS (digital), MEDIPAMEDS0. It does NOT seem that Media PA had any interim period of being served by a #1ESS or #1AESS (non-digital), but was cutover from #5XB directly to a digital ESS, the #5ESS, sometime after 1985 and before 1991, but I don't have the exact date/year of that cutover.

The original 2L-5N "name" would most likely have been "LOwell 6-". There was a new 215-565 added before 1974 (I do not have the year), but it seems that 215-565 was added AFTER 7D ANC (All Number Calling) format started to replace the 2L-5N "name" format. New office codes would not have been "officially" referred to by 2L-5N, although since both 565 and 566/LO.6 are both 56x codes in the same switch, one "could" unofficially refer to 565 as "LOwell 5-". Later 215-NNX codes were added later on, and the town of Media PA also fell on the new/split side of the 215/610 area code split of 1994. VeriZon/BA/B-Pa also has a new

484-NXX code added since 484 had overlaid 610 back in 1999. The ratecenter of Media PA/Philadelphia Suburban Zone #12 also has other 610-NXX and 484-NXX codes "default" assigned to wireless and CLECs as well.

I don't know when the last #5XB (or any other manufacturer's crossbar) in the NANP/DDD network was replaced with (digital) ESS, but it would have been by the late 1990s-era. The last "known" US/Canada SXS office was in Nantes PQ Canada, replaced with a DMS-10 in 2002. The last Panel offices were being pulled from service in the late 1970s or maybe even as late as 1982, I don't remember the "exact" date (year) when the last "known" Panel office was removed from the PSTN/NANP/DDD network. But there are still roughly 60 remaining #1AESS offices in the PSTN/NANP/DDD network as I had mentioned in postings earlier this year.

VZ/BA/C&P has three of them, one each in: Baltimore MD, Richmond VA, Norfolk VA.

at&t ILEC has the rest of them -- a handful in Michigan Bell (four of them to be replaced with digital sometime this year or next year), two in Illinois Bell in Chicago Metro, and several in Southern/South Central Bell and Southwestern Bell, concentrated in certain specific metro areas.

Other than the four known replacements this year or next year in Michigan, I have no idea when at&t or VZ intends on replacing the other remaining 1As. There will still be a few in Michigan even after the four currently known replacements.

But as mentioned in my previous posting, Succasunna NJ #1ESS (which appears to have never been upgraded to a #1AESS) was replaced with a #5ESS in September 1991.

ANYHOW, Sunday 11-July-2010 is the 45th Anniversary of the Florida

305/904 Area Code split in 1965, and it will also be the 62nd Anniversary of the very first public network use of #5XB cut-in at Media PA in 1948. 11-July-1948, 1965, and even 2010 also ALL0 happen to be on a SUNDAY as well.

Mark J. Cuccia markjcuccia at yahoo dot com Lafayette LA, formerly of New Orleans LA pre-Katrina

Reply to
Mark J. Cuccia
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Philadelphia was the last place to use exchange names, finally abandoning them for ANC in 1980. To this day it is not unusual to find a business with stationery or a sign referring to its telephone number by 2L-5N. Some forms mailed out by Phila govt still have MU 6- instead of 686.

However, for new exchanges, they used numbers beginning in the 1960s. This would be for either one of an existing 2L series or a whole new NNX. That is, when BAldwin (22.) needed another exchange in the

1960s, it was called 221. Ini the 1960s many businesses got new exchanges when they cutover to Centrex and these were all ANC from the start (eg 448). (One exception was City Hall was which MUnicipal 6. They've since added 585 to that.)

A tidbit regarding Media, PA: it is served by a trolley line that connects the town with the 69th Street transit terminal (SEPTA's Rt

101). The trolley runs down the middle of State Street in Media, then uses private right of way. Media is also served by a commuter rail station of the ex-Pennsylvania Railroad West Chester branch (now terminates at Elwyn).

The crossbar in Media was also used for a trial test of push-button dialing. Modified 300 sets with buttons plucking reeds were used.

I believe Philadelphia was the first installation of the No. 4 crossbar, a toll switch, circa 1944. That and the 4A became a mainstay of the postwar long distance network.

Bell System history seems to greatly emphasize the No. 5 Crossbar switch as a major invention capable of so many functions, yet, they seem to minimize the contributions of the No. 1 crossbar.

Reply to
Lisa or Jeff

I don't know anything about the No. 1 crossbar, but the No. 5 was a very capable end-office platform.

The town I moved to in 1979 had a No. 5 XBAR until it was replaced by a DMS-100 in 1984. Not only was the No. 5 XBAR very fast with DTMF dialing, any number in a 1,000 number group could be made to hunt to another nonconsecutive number in that group (although it may have had to be ascending; don't recall for sure). This was after suffering at a previous location with a GTE SxS that required a number change to get into a hunting group, then hunting was only to a upward consective number in that hunting group.

Of course, with electronic switching hunting has no limits within the switch and can even be arranged to circle hunt a customer's group for a designated number of loops.

Reply to
Sam Spade

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