Switching History (was How's Pat?) [Telecom]

Wes Leatherock wrote:

>> With all due respect, Bell/W.E. did not design SxS. >> That was done by, or at the behest of, a Kansas City >> undertaker named Strowger, as I recall. >> >> When the first dial office was established in >> Oklahoma City, in 1920, it had to come from >> Automatic Electric, since there was none from >> Bell/W.E. >> Some of it was still is service into the 1950s >> and I think probably another 10 years or so late. >> (Additions to the office, and other SxS offices in >> Oklahoma City, starting in 1927, were W.E. equipment, >> since they had discovered by then that not all of the >> U.S. is served by great megaplexes and there was also >> a need for dial equipment for smaller cities where >> common control would have been, to put it mildly, an >> absurdity. > Step gone by the 1950's? Maybe in the Bell System, > but not at independents - Try 1986 for the last > "100% Mechanical Step" office, and at least 1992 for > it to all be cut out of service through digital > switch expansions and replacements.

Wes can ring in here as to what he meant by his statement:

"Some of it was still is service into the 1950s and I think probably another 10 years or so late." ...

but I'll chime in here as to how *I* read that, in context.

I don't think that Wes was referring to SXS switching "as a whole" being "gone by the 1950s", whether in Bell or the entire telco industry.

Rather, I think he means that the *ORIGINAL AE-made/installed* SXS equipment for Southwestern Bell's Oklahoma City was still around in the 1950s/60s, neither replaced by WECO-made SXS, nor replaced by (WECO) #5XB.

I wouldn't know if any BOC which had 1920s-era SXS from AE ever had *THAT* (AE) SXS replaced at some point with WECO SXS.

Bell began adding #5XB to "Step cities" and areas starting in the

1950, and then began adding ESS to such "Step cities" during the 1960s/70s. It usually wasn't until the 1970s/80s until Bell began *REPLACING* SXS in cities and decent sized towns with ESS (and Digital). And it usually wasn't until the 1980s/90s era until Bell began replacing remaining SXS in small towns and rural areas with (digital) 5ESS and Northern Telecom DMS (and other makes and models; usually remotes at that, except for a "host" switch in some centralized town). And this replacement rate/schedule of SXS with ESS/Digital by Bell was usually the same replacement schedule and rate of SXS with ESS/Digital by non-Bells.

ROUGHLY... the 1970s/80s for big cities and towns, the 1980s/90s for smaller towns and rural areas, for large scale conversions of SXS to ESS/Digital, both Bell and independent, in both the US and Canada.

There were a few remaining SXS offices in the US and Canada in the late 1990s and early 2000s, which have all been replaced with digital, usually remotes, by 2002. Bell Canada replaced a few remaining SXS offices in Ontario and Quebec in 1998. The independent telco in the tiny rural Quebec hamlet of Nantes was still SXS, being replaced with a Nortel DMS-10 in June 2002, and that is thought to be the LAST SXS public exchange in the North American Network to finally be replaced with ESS or Digital. It was not replaced with a digital remote, but rather a (small) DMS-10 (standalone). Nantes is the only exchange of its own independent telephone company. If they would have chosen a (digital) remote from Nortel, they would have had to contract with Bell Canada for "hosting" from one of Bell's nearby full-fledged DMS host switches -- so Nantes chose one of the smallest "standalone" DMS switches from Nortel. I don't know when the last US SXS office was replaced with digital, but there were still a FEW (but not many) such SXS offices in some GTE and other independent areas, in the Midwest, in 1998/99. I think that just about all of these were part of a "crash" replacement plan in time for Y2K. Yet electromechanical SXS doesn't seem like it would have been directly affected "itself" by Y2K issues!.

- a/b

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Anthony Bellanga
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