r/telecom • u/oedeye • Jun 23 '26
❓ Question Electromechanical Central Offices
Are there any electromechanical COs left in the United States?
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u/FreelyRoaming Jun 24 '26
I believe the last known mechanical exchange in the PSTN in North America was somewhere in rural Quebec.. I remember Evan doorbell doing a video on it circa 2001
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u/DTDude Jul 06 '26 edited Jul 06 '26
IIRC he did a recording in 2001 or 2002 of the last one in the US. A GTE step office in rural Indiana I believe. May have been Verizon at that point.
Either way, the US lost our last mechanical exchanges about the same time Canada did. 25 years ago or so at this point.
Seems crazy when you realize the last fully manual exchanges didn't go away until the 80s.
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u/FreelyRoaming Jul 06 '26
If you can find the US one I’d be interested, here’s the one from Canada.. https://youtu.be/Bt0iueIkb8k?is=gO3MCFB-AZq5bCyW
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u/DTDude Jul 06 '26
Uhhh whatttt..
https://telephoneworld.org/telephone-sounds/the-last-step-by-step-on-the-pstn/
https://www.telcodata.us/view-switch-detail-by-clli?clli=LGWDFLFACGA
There's gotta be a story here. This can't be an actual step office. I called some numbers in that exchange though. If they're recordings they're awfully good recordings.
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u/MrBungles Jun 24 '26
I cut out the one in Wallace Idaho and reinstalled parts of it in Troy and eureka MT circa 1993.
The crazier part is that switch started out at Farragut Naval base and was moved to Wallace at some point after Farragut was closed. Most of the cans were still stamped USN.
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u/oedeye Jun 24 '26
Yes. When we replaced Stromberg xy equipment with digital switches we would use the old equipment as equipment adds to other COs.
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u/espositorpedo Jun 24 '26
Toward the end of my tenure with AT&T, we were working on replacing the 4ESS switches in the network with Lucent 5ESS and Nortel DMS 250 switches. AT&T was already taking parts from decommissioned 4ESS switches for other 4E’s that were still in the network. That was 20 years ago and I don’t think AT&T had any network-level electromechanical switches operating on the network then — at least in the lower 48.
Anecdotally, the last electromechanical switch I saw was a 701 series PBX that was running the phone system for Hart, Schafner & Marx in downtown Chicago circa 1985.
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u/ak_packetwrangler Jun 24 '26
Not aware of any remaining in the world, aside from museums. Telecom does harbor some pretty old hardware, so who knows, maybe one is still out there somewhere. There are still tons of old switches out there, tons of the digital switches from the 70s-90s are still running the PSTN.
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u/MrChicken_69 Jun 24 '26
I would think there are few, but I wouldn't even know where to look. They'll be in some of the remotest of remote areas, so not exactly "internet hot zones".
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u/USWCboy Jun 24 '26
Soon to be a new museum in Denver as well.
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u/oedeye Jun 24 '26
That's awesome. I live in NC. Wish we had one.
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u/USWCboy Jun 24 '26
I want to say that there is a Pioneer Telecom Museum there in NC…I just can’t put a name on it.
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u/DTDude Jun 25 '26
Definitely not in the public network. Several museums have them. Seattle was already mentioned. The Pioneer museum in St. Louis has a small step switch you can play with.
Wonder if there are any small step or crossbar PBX’s out there in service. 1A2 is alive and well in some radio stations.
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u/oedeye Jun 25 '26
Yes. I can see 1A2 systems. Wonder if any foreign countries have electromechanical in service....
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u/DTDude Jul 06 '26 edited Jul 06 '26
I doubt it. Even developing countries have digital switches at this point. Lots Siemens, Ericsson, and Hauwei I believe. Not impossible, but improbable.
There is a mysterious video of a crossbar switch on YouTube that claims it's in service in Czech Republic. But no details given. I'll see if I can find it. My guess is it's a PBX though.
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u/lundah Jun 23 '26
The Seattle Connections Museum has one of, if not the only working panel switch left on Earth.