I remember old timer kiwi radio hams telling me (literally) war (WW2) stories of people laying earth return phone lines (ie a single insulated wire with a watered earth stake for a return path at each end) - they were laid along the front in North Africa for RF-free communication.
At one point someone rung down the line and was answered "jawohl?" ..... hung up immediately ..... seems the germans were doing the same thing, path of least resistance was the 2 copper wires ... they found a German speaker to listen in until the front moved
Those old timers told some great stories, don't know how true this one was, it's at least plausible
Another thing I learned recently is above-ground telephone lines on poles are pressurized. Those long black tubes on the cables are splices that also allow the pressure to be read by sensors. The central offices had compressors that fed all the cables.
For those curious why, it’s to prevent water from leaking in. Instead, air from the pressurized interior will push out. This forces humid air to circulate with desiccants at various points, which will pull moisture from the enclosure.
Lastly, the sensors identify pressure dips, which tells technicians roughly where the leak is. Then they know which portion of cable to repair or replace.
Underground lines, too. The same cable might be underground and aerial and underground again, several times over its length. It would be installed in segments (1200-pair cable is heavy and you don't get much on a spool anyway) and spliced, but the splice cases are pressure vessels with gaskets at each cable entry and exit, so there's air continuity to the next segments. The cable might branch at several points, but again, sealed splices mean the whole branching structure is pressurized.
The cycling of the compressor, and the periodic click-hiss of the dual-column desiccant dryer, was an ever-present noise in the basement of every CO. Somewhere over near the air plant, would be a rack full of panels of pressure and flow gauges, and a bundle of tubes taking them over to the individual sealed splice closures where the air was injected into the cables.
A cable pressurization logbook sat on a shelf in the gauge rack, and one of the CO tech's duties was to periodically (weekly?) write down the readings from all the gauges, and compare them to last week and last year. Significant increases were handed off to the outside-plant crews.
At some point, typically where the branched cables ended at cross-connect boxes, the end of the cable would be sealed (air blocked by epoxy potting around the end), and the small lines leaving the crossbox would be icky-PIC instead of pressurized.
Thank you for posting that site. That has led me down multiple rabbit holes that filled my Sunday morning! I love civil infrastructure stuff, and this just tickled the right part of my brain.
I'll provide one of my favorite civ-infra resources, Practical Engineering[1]
My dad told me stories from early in his career at GTE about replacing barb wire phone lines in the 1950s and 1960s in rural southern Illinois. Most of those systems were hooked up to wooden hand crank phones mounted on the wall in houses and barns. He said they would make piles of those old phones and then burn them all.
One other thing I remember from those stories was a lot of the systems were wired in a way that picking up the phone would cutoff anyone farther down the line - so no party line snooping which I remember doing in the 1970s and early 1980s on the phone at my grandmas farm in rural southern Indiana.
I was just talking about this the other day at work. I grew up in rural North Dakota and a guy was asking me if we still had these when I was a kid. No, we didn't. I'm 36.
I remember old timer kiwi radio hams telling me (literally) war (WW2) stories of people laying earth return phone lines (ie a single insulated wire with a watered earth stake for a return path at each end) - they were laid along the front in North Africa for RF-free communication.
At one point someone rung down the line and was answered "jawohl?" ..... hung up immediately ..... seems the germans were doing the same thing, path of least resistance was the 2 copper wires ... they found a German speaker to listen in until the front moved
Those old timers told some great stories, don't know how true this one was, it's at least plausible
Kia kaha!
Another thing I learned recently is above-ground telephone lines on poles are pressurized. Those long black tubes on the cables are splices that also allow the pressure to be read by sensors. The central offices had compressors that fed all the cables.
http://cityinfrastructure.com/single.php?d=RuralOutsidePlant...
For those curious why, it’s to prevent water from leaking in. Instead, air from the pressurized interior will push out. This forces humid air to circulate with desiccants at various points, which will pull moisture from the enclosure.
Lastly, the sensors identify pressure dips, which tells technicians roughly where the leak is. Then they know which portion of cable to repair or replace.
Underground lines, too. The same cable might be underground and aerial and underground again, several times over its length. It would be installed in segments (1200-pair cable is heavy and you don't get much on a spool anyway) and spliced, but the splice cases are pressure vessels with gaskets at each cable entry and exit, so there's air continuity to the next segments. The cable might branch at several points, but again, sealed splices mean the whole branching structure is pressurized.
The cycling of the compressor, and the periodic click-hiss of the dual-column desiccant dryer, was an ever-present noise in the basement of every CO. Somewhere over near the air plant, would be a rack full of panels of pressure and flow gauges, and a bundle of tubes taking them over to the individual sealed splice closures where the air was injected into the cables.
A cable pressurization logbook sat on a shelf in the gauge rack, and one of the CO tech's duties was to periodically (weekly?) write down the readings from all the gauges, and compare them to last week and last year. Significant increases were handed off to the outside-plant crews.
At some point, typically where the branched cables ended at cross-connect boxes, the end of the cable would be sealed (air blocked by epoxy potting around the end), and the small lines leaving the crossbox would be icky-PIC instead of pressurized.
Thank you for posting that site. That has led me down multiple rabbit holes that filled my Sunday morning! I love civil infrastructure stuff, and this just tickled the right part of my brain.
I'll provide one of my favorite civ-infra resources, Practical Engineering[1]
[1] https://www.youtube.com/@PracticalEngineeringChannel
Now this is a real website!
Related:
Barbed Wire Fences Were An Early DIY Telephone Network - https://news.ycombinator.com/item?id=30231837 - Feb 2022 (64 comments)
To add to your list, this article and episode of 99 Percent Invisible covers the topic well too: https://99percentinvisible.org/episode/devils-rope/
Worth a listen!
With the right setup, barbed wire can even carry gigabit Ethernet!
https://www.sigcon.com/Pubs/edn/SoGoodBarbedWire.htm
Another use with barbed wire, we ran an x.25 network across it on a very large ranch with nodes 1 mile apart.
With network monitoring we could now detect breaks in the fence at a 1 mile increment to let the ranch hands know where to go and when it broke.
My dad told me stories from early in his career at GTE about replacing barb wire phone lines in the 1950s and 1960s in rural southern Illinois. Most of those systems were hooked up to wooden hand crank phones mounted on the wall in houses and barns. He said they would make piles of those old phones and then burn them all.
One other thing I remember from those stories was a lot of the systems were wired in a way that picking up the phone would cutoff anyone farther down the line - so no party line snooping which I remember doing in the 1970s and early 1980s on the phone at my grandmas farm in rural southern Indiana.
I was just talking about this the other day at work. I grew up in rural North Dakota and a guy was asking me if we still had these when I was a kid. No, we didn't. I'm 36.
https://en.wikipedia.org/wiki/Party_line_(telephony)