If you're looking for extreme-detail historical information and actual video footage of operating centrol offices, you need to head over to the Internet Archive at archive.org RIGHT NOW.
1935 Movie: Development from the beginning in 1877 to 1935, shows a map of the US as local exchanges were first installed, then long distance lines, and intercontinental lines. How loading coils improve the distance of signals, how the vacuum tube produced an explosion of growth.
1950s Movies: Customers did not have dials. They pick up a handset on a party line and then a central office human phone operator makes the call for them on partially automated dialing equipment.
How operator toll dialing worked before automation, how the "new" automated switched toll dialing works, sounds of the early DTMF tones, a view of the relays and equipment of the CO, the construction of switching equipment at a Western Electric factory, the process of upgrading to automation across the United States.
I haven't read this entire thread, but I scanned and one post by Wayne caught my eye. He said that "most Bellsouth CO's are so clean you can eat off the floor." As a turf vendor who installs in over 100 CO's, I partially agree with that statment. The one that is totally false is when he claims that they're "hardly noisy at all."
Todays CO's are incredibly loud. There is no debating that. The Nortel switches hum like mad, and the Alcatel backbone is horrible. Probably the worst of all is the cooling fans of the Alcatel 1000's. In a moderate sized office these DSLAM's were lined up 4 to 40 bays deep, and had 2 to 3 fans per bay!
A close third are the Cisco GigE switches... the 7600's I think? One local tech even called in OSHA because he felt his desk was to close to the Nortel switch. I don't know what OSHA said, but his desk was moved...
LMAO then you need to go visit some SxS and Crossbar COs.
Yes yes I know they don't exist now. But I would imagine the original poster was referring to them being quiet compared to these two monsters. You ain't heard noise 'till you've heard a SxS or XB switch in action.
Edit - Fans hum or roar... But there's nothing out there now that sounds like a group of 100 people, all holding a coffee can of nuts and bolts, and shaking them all at once.
I've had the pleasure of working in many C.O.'s. All Bell. I can tell you that an RBOC C.O. makes most IT or computer rooms look like dumps. FWIW, when times were slow we would actually *armor all* the vault cables as we went along checking bonds / grounds.
There is a certain smell to C.O.'s which is universal. It's not a bad smell, just unmistakable. It's almost pleasant if you don't have to be in there every day. Anyone who's been in one knows what I mean.
The best was being in there on Mothers Day before the digital switches went in. What a noise! The clickety-clack has now been replaced with the droning hum of fans (much like server fans). The new switches are tiny compared to the old. Many offices still use the old "cosmic" side of the frame with the new switches, which is laughable since it outsizes the switch it serves 2:1. -- Looks like Reverend Wright got his wish - God Damn America.
This is what I started on in 1966.Called a Step by Step switching system.Before X-bar and Electronic Switching.There would be thousands of different types(Line Finder,Selector,Connector) in a good size office.They had to be physically maintained.Cleaning,Lubing,adjusting,etc.
There was a time, not that that long ago, when Ma Bell would have called upon the strength of the mightiest communication system in the world (One System it Works) to restore service quicker then any entity known to man. This without any taxpayer bail-out or congressional filibuster.
Alas the people have what they were suckered into demanding and yet they complain.
I was in a frontier c/o late last year. I asked if I could take a tour and see what was what. Their setup was very nice and organized but had thousands of wires running through the racks. Most of their servers and switchs were in padlocked network enclosure racks. It was pretty neat but I don't have any pictures. -- The Gun News Blog, the latest information on the firearm industry.