When Thousands of Cables Crowded the Skies

[Neomys Sapiens]

Where cable cutting becomes really fun is when you do it an medium voltage (1...50kV) and UNKNOWN source and fusing. The device used for that is powered by a sizeable blank cartridge and actuated by a pull line (sometimes even run through some blocks depending on pucker factor). 

[Red Squirrel]

I used to have occasional duties in the big room behind the 20-attendant cordset (old-school operator switchboard).  It was a room full of twenty-four big 2-volt cells, each as big as a refrigerator (in series for 48V)  And the center of the room was hundreds (thousands?) of Strowger switches (2-dimensional relays) which implemented direct-dial between all the hospital/university campus buildings.  What a humongous hunk of clacking mechanism.  Truly an electromechanical marvel of a previous era.

Those battery cells are quite impressive.  We have 4 strings of 48v here, batteries maybe the size of a typical beer cooler set sideways.  Lots of power!   Nothing electromechanical left though well other than standard relays I guess, lots of those in line cards etc.  When you go behind the switch you can hear them go on and off as phones go off hook. 

Never got to see a full electromechanical switch in action but I heard it's quite loud and techs would get hearing loss after many years of working near them.

[schmitt trigger]

Imagine how many birds could rest there?

I live in a bird migratory path. In the mid autumn and late winter, many 13.8 kV lines are brim full with migrating birds. It so happens that if you are standing at a red light, your vehicle will be mercilessly bombarded with poop.
Once, in the twilight of early morning, I saw an enormous flash, followed by birds fragments falling down. The birds were so densely packed that they had actually shorted the lines.
The enormous flock cried and cackled, and speedily flew away.

What was most interesting was that for several days, no birds, or close to no birds, actually stood in the wires at that particular intersection!
But of course birds having bird brains, they quickly forgot and filled the wires again after a few days.

[duak]

I've been on tours of electromechanical exchanges back in the 70s and they're not super loud, like an unmuffled engine or an electric saw, but the continuous sound with local transients would cause some hearing damage over time.  (Huh? Whad'ja say?)  There was always a tech going around and cleaning the contacts.

Back then I wanted a Strowger switch but they weren't giving any away.  I did get some surplus telco relays and circuit multiplexing equipment.  Most of the vacuum tubes had 48V heaters and gold plated pins.  The resistors were all 5% or 1%, a rarity to me as most consumer electronics were mostly 10% or worse.

Interesting story - I grew up in a city that was on a telco that used Siemens equipment rather than AEL (Automatic Electric).  The local company was later integrated into its parent and the Siemens exchange was replaced, probably with a touch tone compatible design.  They had some trouble because the pulse dialing mechanisms in the customers'  phones had to be slowed down to work with the replacement AEL equipment.

[Richard Crowley]

Automatic Electric was the equipment supplier to the "second-string" GTE operating companies (in areas not covered by Bell Telephone).  And Automatic Electric was regarded as the "second-string" equipment supplier as a result.

The Automatic Electric rotary dials didn't have a centrifugal friction governor like the Western Electric/Bell Telephone dials had.  So they probably pulsed faster than the WEco/Siemens, et.al. central office switches could handle.

Our Uni/Hospital was in one of the last (and oldest) remaining GTE operating areas.  The phone company had retro-fitted some kind of kludgy DTMF detectors onto their mechanical crossbar switch and they had a high failure rate.  I remember more than a few times having to "dial" by pulsing the hook-switch because the DTMF Touch-Tone was on the blink again.

The old crossbar switch must have been past is prime. It even had a unique "wait for me, I'm working on it!" tone.  It sounded like "tick...tick...tick...tick" in retrospect perhaps the sound like a ticking time-bomb. (Which is probably what the poor support engineers must have imagined trying to keep that thing running!)  I once had nothing better to do and sat there for 20 minutes listening to the "tick-tone" before hanging up and re-dialing.

The Hospital/Uni finally had so much trouble with the GTE local telephone company, they "jumped the shark" and put up their own microwave link across the freeway to the adjacent city that had the latest Western Electric switch.  They rented a little storefront as a "demarcation point" in the adjacent city to interconnect to the Bell operating company. What a difference: like night and day.  Rumor was that the GTE office manager was sacked over losing what may have been their largest customer.

And their billing was terrible as well.  For around a year I got phone bills filled with long-distance calls to people I never heard of, at times I wasn't home and even to disconnected numbers.  After a few months, I started getting wrong-number calls for "Enrique deSantos" from people who spoke no English.  I suspect that somebody made a random tap onto my subscriber pair and was illicitly using my telephone service.  So maybe it was their "outside plant" (wiring) security and not the billing that was the problem.   

[Richard Crowley]

At the opposite end of the spectrum from skies full of hundreds of wires, was the "G-line".
I remember driving through vast (at least it seemed to me at time time) deserts of inland S.California.
There were wood utility poles along the lonely highway, many with just a single strand of cable.
But instead of a glass knob insulator, etc. at the utility pole, there were a pair of funnels.
One funnel to "catch" the open-wire "coaxial signal" and on the other side a funnel to "launch" the next span.

Ref: https://en.wikipedia.org/wiki/Goubau_line

[duak]

Richard, you called it!  The telco was called BC Tel back then and I understand they were owned by GTE.

I was also getting spurious charges so for about a year I'd have to call customer service when I got my bill to have them removed.

I remembered a story my father told me about the time he drove a logging truck home.  He said it was kind of "pulling heavy" on the last block to our house.  When he stopped and looked up he found that the boom had collected a number of phone lines.  The telco tried to pin it on him and the trucking company but it was their fault because they strung their lines below the minimum height.

[vk3ase]

Footage of some impressive overhead lines in Parks New South Wales but pulled down not long after this was shot in 2007.

[NiHaoMike]

At the opposite end of the spectrum from skies full of hundreds of wires, was the "G-line".
I remember driving through vast (at least it seemed to me at time time) deserts of inland S.California.
There were wood utility poles along the lonely highway, many with just a single strand of cable.
But instead of a glass knob insulator, etc. at the utility pole, there were a pair of funnels.
One funnel to "catch" the open-wire "coaxial signal" and on the other side a funnel to "launch" the next span.

Ref: https://en.wikipedia.org/wiki/Goubau_line

I wonder if that could be used to send data over power line, with far more bandwidth than could be done by merely superimposing lower frequency RF onto the line.

[GlennSprigg]

Just my 2c worth...
The Australian Overland Telegraph Line was a 3200 km telegraph line that connected Darwin with
 Port Augusta in South Australia. Completed in 1872, the Overland Telegraph Line allowed "fast"
communication between Australia and the rest of the world !!!
Of course this elementary 'Morse-Code' required quite a few 'Repeater' stations. One of the most
famous of those is at 'Alice-Springs', roughly at the centre of Australia.
There are still the remnants through the Bush, of this single line...
I have stood under many sections of that old line, while using my 'Smart-Phone'...
Can't help thinking of the VAST difference since the original conception!

Due to the distances that we have to deal with here in Australia, wilh very little inbetween, we
have been pioneers in certain technologies since then. My father was instrumental in a LOT of
the progress of long distance Microwave Communication since then, across our vast country.
And before his retirement/death, the new Fibre-Optic nation wide links. (All way pre N.B.N.)

[bd139]

I remember as a small child in the late 50s and early 60s seeing a mess like that in streets of Victorian houses in London. By the mid 60s it had all been replaced by underground cables.

It amazes me how much old-school technology that still exists in use in the U.K.

Yes we've still got a lot of telephone poles round here in SW London. In fact they've been installing fibre manifolds on them over the last few weeks. 300 mbit FTTP off telephone poles seems weird.

This picture brings it into perspective. Standard training for our telecoms guys (openreach):

[German_EE]

Training must have got tougher. I remember seeing a picture in a GPO press release showing engineer training and the poles were only about 3m high. It looked weird to see men working on such small poles but the Health and Safety advantages are obvious.

[Neomys Sapiens]

Training must have got tougher. I remember seeing a picture in a GPO press release showing engineer training and the poles were only about 3m high. It looked weird to see men working on such small poles but the Health and Safety advantages are obvious.

Maybe they need to sort out those that became too sick to splice properly on the real poles!

[Red Squirrel]

They should convert that into a telecom competition.  Who can bring fiber to the designated NID the fastest wins. 

[Richard Crowley]

I wonder if that could be used to send data over power line, with far more bandwidth than could be done by merely superimposing lower frequency RF onto the line.

That was called "Power-line communication" aka. "Power-Line Carrier"
https://en.wikipedia.org/wiki/Power-line_communication

Widely opposed by Radio Amateurs (hams) because the genius engineers at the power companies thought they could get away with using whatever frequencies they wanted because "it wasn't being broadcast into the air".  Of course mile after mile of wire hung in mid-air made perhaps the best broadcast antenna one could hope for.  So the concept suffered a well-deserved demise.

[bd139]

Ironically that works in reverse. We have overhead telephone poles here and they rather like a bit of HF which overloads every router’s front end at 50W or more 

[Neomys Sapiens]

Ironically that works in reverse. We have overhead telephone poles here and they rather like a bit of HF which overloads every router’s front end at 50W or more 

But you can always borrow a unused quad or pair and short them together to get some improvement in LW reception!
It has to be the right direction although, unless you are living next to the rural star point, where you get some options.