Telephone Networks (and alternate uses for them)

[swaghauler]

Originally Posted by Olefin

So if I am reading what you are saying correctly basically local service should work as long as you have an analog phone and possible from town to town if they were close together even without repairs. I assume the grounding boxes would be relatively easy to fix versus the switching stations

And if you went back to manual operators you could place longer calls but only with an established network of such operators. If not you would need to replace the computer switching stations for sure to be able to get regional or long distance phone calls working.

Would this be the same for using a telegraph key - ie lower amount of data being transmitted - would that make any difference or in reality it’s the same amount of effort as restoring phone service and thus not really any advantage?

Correct. The switching system replaced the old human operators who connected calls into the '80s in some places. Humans can be used to replace the computerized switchers. You could use a TELEX system if you choose to with analog lines. The TELEX is that streaming system that TYPED out messages coming over the phone lines. TELEX paper or "ticker tape" was often thrown out windows during parades. It actually produced text messages before text messages were a thing!

Just remember that analog phones need both a continuous grounded line and a low wattage power source to transmit the messages (verbal or typed). This is WHY there are 2 D-Cell batteries in a field telephone. They provide the power needed to communicate up to 5km with just one phone's power. DISCCOMs can power the equivalent of a city-sized system.

[Olefin]

Opens up all kinds of ideas for adventures to either repair phone lines or get a switchboard back up so that you can restore communications in an area - and of course run into people who might not want that to happen especially if they have a vested interest in keeping people in the dark

[Legbreaker]

One small point. With the computerisation/automation of the telephone system, just how much of the equipment necessary to switch back to human operators still exists?

[Olefin]

Human based operators still exist - basically think of anywhere you call and you get a human being who then connects you internally the right extension instead of automatic dialing systems. A lot of companies still have receptionists who function as operators connecting you with the right people internally.

It wouldnt be as efficient for sure and you wouldnt be able to handle anywhere near the volume of calls that a computer system can handle - but it would definitely allow, for instance, MilGov or CivGov to use human operators at switching stations to make phone calls where the lines were still intact.

Thats where the DISCCOM units come into play with the human operator switching stations that can connect to civilian phone systems when needed.

The real limitations would probably be the ability to generate power for operating the phones and switching stations. The more power you can generate the more phones and switching stations would work - the less power you have the more likely you have something like the town phone where there is one phone working.

[Legbreaker]

Originally Posted by Olefin

Human based operators still exist - basically think of anywhere you call and you get a human being who then connects you internally the right extension instead of automatic dialing systems.

Only place I've ever encountered that is internal communications within a office building or the like. Even then, that was just a case of the caller being too lazy to look up the number for themselves and letting the switchboard operator do it for them and then transfer the call (using the computerised system).

[Olefin]

There are several companies that supply my company with parts and fabrications that if you call them you get a live operator not a computer who then connects you with who you want to talk to - they are getting fewer and further between but back in the 90's it was still very common to have that be the case.

Back in the 90's a lot of Army bases were still using consoles that had just recently replaced switchboards - example is the article I am attaching - Joint Base Elmendorf-Richardson

They used a wire switchboard until 1991 and then switched to a manual console which was still in use during the V1/V2.2 timeline period - the switch to computers didnt happen till later.

https://www.jber.jb.mil/News/News-Ar...e-switchboard/

[Olefin]

http://militarynewbie.com/wp-content...ems-SS0029.pdf

This is from a 1994 US Army Tactical Telephone manual

This would be the type of Equipment that the Army would be using to try to keep phone service going for their units - notice I didnt say for civilians - but it would be enough as you can read to allow MilGov and CivGov, where the lines are functional, to maintain telephone contact with their units.

2. Types of switchboards.

a. Tactical switchboards are divided into two major groups-manual battery and common-battery equipment. At brigade level and up, we find common-battery equipment housed in mobile units.

b. The mobile units get prewired and designed to accommodate the equipment needed for the mission. The shelter has cable receptacles for connecting the 26-pair field cables. They usually contain electrical heaters to warm the personnel and equipment during cold weather. A trailer-mounted power generating unit provides electrical power to the shelter. The next few sub-paragraphs examines the different switchboards found in the field.

(1) SB-993/PT is 6-line analog 2-wire manual switchboard, capable of supporting a maximum of six local-battery telephone circuits or six trunk circuits. (See Appendix A, Figure A-9.) 1-3 SS 0029

(2) SB-22/PT and SB-22A/PT are tactical manual switchboards They can provide service to 12 local-battery telephone circuits. The operator can stack two SB-22s to support up to a 29-circuit system. To support 29 subscribers, the operator must remove the operator pack from the second SB-22. He then
installs a 5-line pack. To interface with the automatic switches, the operator must install a TA-997/PT or tone-signaling adapter. No operator intervention is required when using the tone-signaling adapter.
(See Appendix A, Figure A-10.)

(3) SB-3082(V) /GT can service up to 50 telephone circuits. The SB-3082 can be mounted on a 1/4-ton truck or in a shelter. The operator can set up a conference call for up to six subscribers. The switchboard has an emergency power system. The emergency power system runs on two 12-volt batteries. In addition, the switchboard brings a battery charger for recharging the emergency system. (See Appendix A, Figure A-11.) The picture below is an SB-3082

(4) AN/TTC-38 can interconnect 300 or 600 telephone circuits. We can find the AN/TTC-38 deployed in an area communications center (ACC). The AN/TTC-38 is all analog. The primary telephones used with the AN/TTC-38 are the TA-341, TA-838, and the TA-938. Today, we find most
of the AN/TTC-38s still in service with the Reserve Component units. (See Appendix A, Figure A-14.)

(5) AN/TTC-39A and AN/TTC-39D can service 600 or 672 trunks depending on the model on hand. The AN/TTC-39A provides, for the first time, the capability of miring analog and digital service. It can interface with existing tactical switches (manual and automatic), commercial central offices, and
Defense Switched Network (DSN). In addition, the AN/TTC-39A and AN/TTC-39D can interface with North Atlantic Treaty Organization (NATO) telephone systems. We find the AN/TTC-39D at EAC. (See Appendix A, Figures A-15a through A-15d.) The AN/TTC-39A is found in Army Reserve EAC
units, Air Force units, and the Joint Communications Support Element.

(6) AN/TTC-41 and AN/TTC-41A is an automatic switchboard. The AN/TTC-41 comes in several models. The AN/TTC-41(V) 1 can service up to 30 subscribers; the models V2 and V5 can service up to 60 subscribers; the models V3 and V6 can service up to 90 subscribers; and the AN/TTC41A (V) 4 and 7 can service up to 120 subscribers. (See Appendix A, Figure A-16.) The AN/TTC-41A can interface with the DSN and dial central offices (DCOs). The switchboard is capable of providing 2- or 4-wire service.

(7) AN/TTC-46 or large extension node (LEN) switchboard has basically the same configuration as the node center switch (NCS)(AN/TTC-47). The basic difference is the termination configuration for trunks and loops. The LEN doctrinally is deployed in support of the division support command
(DISCOM) in an MSE division. It can support a total of 164 subscribers using J-1077 and remote multiplexer combiners (RMCs). (See Appendix A, Figures A-17a and A-17b.)

(8) AN/TTC-47 or NCS is the hub of the MSE node. The AN/TTC-47 provides network interface for the subscriber access elements. The AN/TTC-47 provides automatic subscriber finding, deleting the need for knowledge of the subscribers' geographical location. (See Appendix A, Figures A18a and A-18b.)

[Desert Mariner]

Originally Posted by Legbreaker

One small point. With the computerisation/automation of the telephone system, just how much of the equipment necessary to switch back to human operators still exists?

I was in the USAF and as late as the late 80s, many base level switchboards were still 100% human operated using manual plug and patch systems. Some of us had to be cross-trained to operate them in case the civilians ever went on strike. I went through this at Charleston AFB, SC and also Hahn AB in Germany. Most (if not all) of the US bases in Germany at that time still utilized manual switchboards. Computerized versions began showing up circa 1987 even these relied on a human operator to connect calls, we just pushed buttons rather than plugging cords.