hckrnws
A brief history of barbed wire fence telephone networks (2024)
by keepamovin
This is amazing to see. I have some audio recordings, digitized from tapes recorded in the 1960s, of my great-grandfather who was raised on a farm in Iowa. He talks about his experiences in amateur radio in the early 1900s-1920s. He mentioned bringing telephones out into the field that could be clipped to the fence wire to make calls back to the house, which was not hooked up to an electric grid but had batteries. Sadly, he did not say how the batteries were re-charged.
The batteries were either charged using a "telephone magneto", or were taken to a local town to be charged off of mains electricity:
My father in law grew up in the Denver area. His father made his living as a handyman, and one of his regular customers was Molly Brown (the Titanic survivor known as "The Unsinkable Molly Brown"). Every week he would go to her house to exchange her radio battery, then bring the old battery back to his workshop for charging.
From what I understand, the crank was used to ring the exchange's bell, not to reload the phone battery.
Yes, in the old systems, you'd get about 90 volts AC down the line to ring the mechanical bell ringer. Once saw a guy nearly fall off a ladder, splicing phone lines with bare hands. He thought the relatively low voltage was safe enough, but then someone rang him in the middle of the job.
I had to refresh my memory about the hybrid use of AC and DC current in telephone networks.
The Alternating Current signals could be used over longer distances and were effective at making the bells ring, moving the clapper back and forth. This back-and-forth is exactly what makes AC so deadly in the body, should it cross through your cardiac muscles, for example, and set the muscles twitching at 50 or 60 times per second.
There’s nothing inherently deadly about AC nor anything inherently safe about DC. If there’s enough voltage available to drive current through your body, then electricity is deadly regardless of if it’s AC or DC.
In general AC tends to be a little safer than DC, because the voltage is constantly reversing, which means it’s constantly passing through 0V, creating moments where you don’t have current driving through your body and forcing all your muscles to contract. Those 0V crossings create moments where you can let go of whatever is electrocuting you. DC on the other hand has no such 0 crossings, if there’s enough voltage there to drive current through you, then all your muscles will be stuck contracting until either the power is turned off, or until they’re all so fried they’re not physically capable of contracting anymore.
I know 30+ years ago as I kid I learned this in my parents basement as I was rigging something up.
It is more the surprise, as if one is ignorant to this fact it is not expected at all.
> Sadly, he did not say how the batteries were re-charged.
Dry-cell batteries had to be changed, they weren't recharged.
https://www.reddit.com/r/diyelectronics/comments/y7qmhq/15v_...
My grandmother from rural Saskatchewan said that back then they would exchange their radio batteries when they went to town.
Her husband, my grandfather, lived in Regina but worked on a traveling threshing crew and mentioned seeing a windmill driving an old generator from a car to charge batteries at one stop.
The phone batteries weren't a high load kind of affair. They merely needed to change the varying resistance of the carbon microphone into an audio voltage - on the order of milliwatts of power - to send down the line. A more modern phone, still using a carbon microphone but powered by the line, needed about 20mA of loop current to do this. The telephone terms for the old system vs. the newer is "local" vs. "common" battery.
Heavy duty batteries - specifically the "A" batteries that powered the vacuum tube heaters in early radios - were made rechargeable to save cost.
This might be a bit of a tangent but I couldn't help but wonder if the appearance of 20ma here is related to the old fashioned, but I understand commonly used, 4-20ma current loop signalling in industrial applications.
It's almost never a coincidence. Before digital switching everything was done mechanically, and before mechanical switching everything was done by people with plugs. If you have a big enough industry like telephone switching equipment then you're bound to see a lot of suppliers expand their market by selling the same parts outside of their home industry. Current flow is a nice signalling mechanism because you can tell the difference between short, open, and functional circuit. So I'm guessing it got used in telephone switching equipment and then preserved because there was no reason to change.
If the batteries were rechargeable at all (some radio 'A' batteries [0] were), they could have been recharged by a small wind turbine [1].
Maybe they used a Delco-Light Plant
When I was a kid, I scavenged a hunk of cable "Ma Bell" had left behind. I spliced together a quarter mile pair of wires to connect the neighbors house to mine and hooked up a battery and microphone on one side, and a speaker on the other. No luck. Then we connected the "speaker side" to the input of my friends stereo, and it was possible to be heard. I was about 10 at that time ( ~1970) and was not very aware of voltage drop. The taps and recording system I put in our basement worked much better!
If you can get your hands on it, I recommend Other Networks: A Radical Technology Sourcebook by the same author. She covers barbed wire as well as many other ways to communicate. The book itself is gorgeous.
It's on archive.org: https://archive.org/details/emerson-lori-other-networks-a-ra...
>Anecdotally, fence phones were still being used throughout the 1970s and perhaps even later. C.F. Eckhardt describes calling his parents who lived in rural Texas and still used a fence phone; their number was simply 37, designated on the small local network by three long rings and one short ring.
Is this perhaps an OCR or typography error? If the number were "31" that would make much more sense to encode as three long one short. A stylized 1 can look a bit like a 7 depending on how the characters are drawn.
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Some great previous HN discussions on barbed wire telephony:
https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...
There are also discussions about networking over barbed wire.
Very cool to see one comment linking to an old Sears magazine from the 1920s, showing some of the equipment people would have constructed these networks from:
https://babel.hathitrust.org/cgi/pt?id=njp.32101066805050&vi...
The thing I'm most amazed by is how "modern" the catalogue is, especially the clothing and phonograph sections.
I couple years ago I read "A Mind at Play", Soni & Goodman, a biography on Claude Shannon. He grew up on a farm and the book mentions how he made extensive use of barbed wire fence telegraph (and if I recall telephone). Perhaps one of the early experiences Shannon had regarding information.
The MIT Museum had a display (last year) of Shannon's "toys", including the famous mouse maze. I don't recall any mention of his early days using barbed wire telegraph though.
I’ve had that book for several years. This thread has finally motivated me to start it.
"The Bit Player" (2018) film, "The Information" (Gleick) book,
"Who invented the transistor?" https://news.ycombinator.com/item?id=46449618 :
> Who invented the electric fence gate?
> How does the electric fence gate lead to transistors?
> [ Relay, Electric gate, Flip-flop (electronics) ]
/? find a specific transcript from "The Bit Player" and "Claude Shannon: The Father of the Information Age" IEEE Information Theory Society video where the narrator makes the leap from the Morse dots and dashes on fence wire to the math of entropy (and logarithms and channel coding and capacity limits)
If you look in vintage Sears catalogs - easily found online - I have a printed copy somewhere of the 1908 one and it's definitely in there - aftermarket phones had a bit of a "contraband" aspect to them, and were offered to be shipped in unmarked boxes. Not all local phone companies were "friendly" to people stringing up their own lines.
As an aside, Goyte incorporating the Winton Musical Fence into one of his songs.
I talked with someone years ago who did networking deep in third world countries in the 90s and early 00’s. Hey said they would not-infrequently use wire fences for wiring up remote locations using X.25 because the protocol was highly tolerant of very noisy lines, and it was the only way to have any confidence the infrastructure wouldn’t just be ripped out the day after they left.
That’s really cool. I wonder if you could run anything else on a fence network. Like some sort of primitive computer network.
You could probably do AX.25 over barbed wire.
You can run Ethernet over coat hangers, barbed wire should be fine (if slow).
It has already been done... albeit on short distances. See https://news.ycombinator.com/item?id=15910263 (2017 IIRC). This said I wouldn't expect it to work miles away as an analog phone would.
Fascinating!
I was really disappointed not to see any mention of Claude Shannon running barbed wire comms in rural Northern Michigan.
As a native of Northern Illinois, I was pleased to see Joseph Glidden mentioned.
https://en.wikipedia.org/wiki/Joseph_Glidden
Edit: after reading about Claude Shannon, I too think it would have been nice if he was mentioned.
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This is only vaguely related but I've been dying to drop this link after recently learning about the "Carrington Event" in 1859
The most powerful geomagnetic storm in recorded history
Likely from the largest coronal mass ejection in modern human history
The natural EMP effect was so powerful, telegraph operators were able to completely disconnect all their batteries and still communicate for hours
https://en.wikipedia.org/wiki/Carrington_Event#Telegraphs
Imagine some future event even more powerful and our dependence on all those LEO sats...
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Needs more modem.
Crafted by Rajat
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