When Thousands of Cables Crowded the Skies - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: March 28, 2019, 01:40:58 am
content: Amazing!https://io9.gizmodo.com/photos-from-the-days-when-thousands-of-cables-crowded-t-1629961917?IR=T

author: TimFox
author_rank: Super Contributor
timestamp: March 28, 2019, 01:18:36 pm
content: IIRC, the New York City government demanded that these cables be buried (after havoc caused by a blizzard), and then sent crews out to chop down the poles when that order was ignored.

author: coppercone2
author_rank: Super Contributor
timestamp: March 28, 2019, 01:42:48 pm
content: Quote from: TimFox on March 28, 2019, 01:18:36 pmits hilarious sometimes how little people cooperate with the goverment

author: Red Squirrel
author_rank: Super Contributor
timestamp: March 28, 2019, 04:37:30 pm
content: Sometimes those telegraph lines are still standing in places. There's even some in my city. No wires, but you can see the glass isolators still intact. Kinda neat that these pieces of history stay behind.The cable that's on there is most likely fibre optic but at one time there would have been a bunch of supports above for more wires. (can see notches in the pole)

author: orion242
author_rank: Unknown
timestamp: March 28, 2019, 05:14:20 pm
content: Some places thousands of cables still crowd the sky.https://www.dailymail.co.uk/news/article-3185040/Danger-8ft-high-voltage-Lethal-power-cables-dangle-perilously-close-men-women-Old-Delhi-s-no-wonder-poor-electricians-blow-fuse.html

author: Richard Crowley
author_rank: Super Contributor
timestamp: March 28, 2019, 05:39:40 pm
content: Even worse today in many places on the planet....

author: orion242
author_rank: Unknown
timestamp: March 28, 2019, 06:02:52 pm
content: Look at some of those connections.Its just wires twisted to the main with some mechanics wire wrapped over the whole mess.

author: thm_w
author_rank: Super Contributor
timestamp: March 28, 2019, 08:57:53 pm
content: What freaks me out is when the wiring is hanging down into the sidewalk, low enough to walk into. 99.9% chance its a low voltage RF signal or not connected to anything, but still don't want to go near it.

author: coppercone2
author_rank: Super Contributor
timestamp: March 28, 2019, 09:02:27 pm
content: imagine how satisfying it would be if a car crashed into one of those poles and tool it out

author: GregDunn
author_rank: Frequent Contributor
timestamp: March 28, 2019, 09:43:43 pm
content: Quote from: EEVblog on March 28, 2019, 01:40:58 amFrom before they had telephone exchanges, and everyone needed to run a wire between the conversing parties.

author: Domagoj T
author_rank: Frequent Contributor
timestamp: March 28, 2019, 10:35:45 pm
content: Quote from: Homer J Simpson on March 28, 2019, 04:59:06 pmSo the guy says that the cutters were specially sharpened so as not to cause shorts. Anybody got an idea what is this special sharpening technique? How many conductors would these cables have anyway?Also, I suppose the new connections for new system were made before cutting and then electronically switched over?Fascinating procedure. Probably took months to prepare.

author: EEVblog
author_rank: Unknown
timestamp: March 28, 2019, 10:48:02 pm
content: Quote from: Domagoj T on March 28, 2019, 10:35:45 pmProbably 100 pairs or so. Just the small standard one coming into my lab has 15 pairs.

author: thm_w
author_rank: Super Contributor
timestamp: March 28, 2019, 11:44:16 pm
content: Quote from: Domagoj T on March 28, 2019, 10:35:45 pmProbably just the curvature of the blade, helps keep the original cable in its rounded shape avoiding permanent shorts. And reasonably sharp with an even grind of course.https://www.kleintools.com/catalog/high-leverage-cable-cutters/electricians-cable-cutter-insulatedhttps://www.kleintools.com/catalog/specialty-cable-cutters/multi-cable-cutter-klein-kurveCausing shorts while the cable is being cut, I can't see how that would be avoided.

author: Red Squirrel
author_rank: Super Contributor
timestamp: March 28, 2019, 11:46:40 pm
content: That's an interesting way to do the cut over, so I assume they were already spliced to the new switch ahead of time but the switch was not active so they cut the cables going to the old switch and then turned the new switch online?That beats having to rerun each individual jumper to new line equipment one customer at a time. That's kind of how I figured it would normally be done.Where I sit in my office is where our stepper switch used to be. It got transferred to the DMS100 in the mid/late 70's and the switch has been running since. Solid equipment!

author: Richard Crowley
author_rank: Super Contributor
timestamp: March 29, 2019, 12:13:13 am
content: Quote from: Red Squirrel on March 28, 2019, 11:46:40 pm"These cable cutters are sharpened in a special manner so they will cut a clean cut through these and not cause any shorts."I was wondering about that when I first saw this video a couple years ago. If it caused a short on the new equipment side, it could short out somebody's subscriber pair and render their telephone service dead. At least until the cut cable was disconnected from the new equipment side.QuoteYeah, they showed a close-up of the manager casually reaching up and flipping the toggle to enable the new switch. In the video production biz, that is called "the money shot"QuoteI 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.

author: amyk
author_rank: Super Contributor
timestamp: March 29, 2019, 01:33:29 am
content: Maybe I'm the crazy one here, but I'd actually like to live for a little bit (not too long) in that era. Not the more modern monstrosities posted below, but the world in the picture of the second post by Dave. Imagine being young and alive when the telephone first gets invented and popularised...

author: Cubdriver
author_rank: Unknown
timestamp: March 29, 2019, 02:25:26 am
content: Quote from: Domagoj T on March 28, 2019, 10:35:45 pmI'd imagine that they're just really nice and sharp, so as to shear very cleanly and not 'smear' the ends of the conductors so they project past the insulation. The cables would probably be 100 pair, #24 AWG copper.Pretty impressive performance, and yeah, I'm sure it took months to get everything ready. Pretty mind blowing that they could then make the transfer in under a minute! As much at people here in the US used to bitch about Ma Bell, I doubt many have any idea how much of the technology that's taken completely for granted came from their research and development labs. Little things, like, for instance, the transistor.Cool video.-Pat

author: coppice
author_rank: Super Contributor
timestamp: March 29, 2019, 02:42:31 am
content: Quote from: EEVblog on March 28, 2019, 01:41:54 amI 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.

author: electromotive
author_rank: Regular Contributor
timestamp: March 29, 2019, 03:18:25 am
content: Quote from: coppice on March 29, 2019, 02:42:31 amIt amazes me how much old-school technology that still exists in use in the U.K.

author: Mr. Scram
author_rank: Super Contributor
timestamp: March 29, 2019, 03:30:34 am
content: Those old pictures are great. We take hidden cables for granted now.

author: Richard Crowley
author_rank: Super Contributor
timestamp: March 29, 2019, 04:21:26 am
content: Quote from: Mr. Scram on March 29, 2019, 03:30:34 amThe cables these days tend more and more to be optical fibers that are as thin as you hair.Most of their diameter is physical protective sheath to keep the fibers from breaking.I just watched a YT video about a submarine cable landing facility in Denmark.At one point they show the cable which is the better part of 100mm diameter with all the layers of armor.But the "payload", the optical fibers, are barely visible wisps coming out the end.Cue: Around 3:16 in the video. [

author: Electro Detective
author_rank: Super Contributor
timestamp: March 29, 2019, 08:43:15 am
content: The Wichita Lineman would have scored big time if he worked in New York back then

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: March 29, 2019, 03:36:52 pm
content: 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).

author: Red Squirrel
author_rank: Super Contributor
timestamp: March 29, 2019, 03:42:57 pm
content: Quote from: Richard Crowley on March 29, 2019, 12:13:13 amThose 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.

author: schmitt trigger
author_rank: Super Contributor
timestamp: March 29, 2019, 04:09:05 pm
content: 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.

author: duak
author_rank: Super Contributor
timestamp: March 29, 2019, 05:59:43 pm
content: 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.

author: Richard Crowley
author_rank: Super Contributor
timestamp: March 29, 2019, 06:30:13 pm
content: 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.

author: Richard Crowley
author_rank: Super Contributor
timestamp: March 29, 2019, 06:45:34 pm
content: 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

author: duak
author_rank: Super Contributor
timestamp: March 29, 2019, 10:14:56 pm
content: 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.

author: vk3ase
author_rank: Newbie
timestamp: March 30, 2019, 03:33:18 am
content: Footage of some impressive overhead lines in Parks New South Wales but pulled down not long after this was shot in 2007.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 30, 2019, 04:07:32 am
content: Quote from: Richard Crowley on March 29, 2019, 06:45:34 pmI 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.

author: GlennSprigg
author_rank: Super Contributor
timestamp: March 31, 2019, 12:34:39 pm
content: Just my 2c worth...The Australian Overland Telegraph Line was a 3200 km telegraph line that connected Darwin withPort 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 mostfamous 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, wehave been pioneers in certain technologies since then. My father was instrumental in a LOT ofthe 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.)

author: bd139
author_rank: Super Contributor
timestamp: March 31, 2019, 12:44:57 pm
content: Quote from: electromotive on March 29, 2019, 03:18:25 amYes 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):

author: German_EE
author_rank: Super Contributor
timestamp: March 31, 2019, 07:24:59 pm
content: 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.

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: March 31, 2019, 10:04:09 pm
content: Quote from: German_EE on March 31, 2019, 07:24:59 pmMaybe they need to sort out those that became too sick to splice properly on the real poles!

author: Red Squirrel
author_rank: Super Contributor
timestamp: March 31, 2019, 10:37:47 pm
content: They should convert that into a telecom competition. Who can bring fiber to the designated NID the fastest wins.

author: Richard Crowley
author_rank: Super Contributor
timestamp: May 08, 2019, 06:49:58 am
content: Quote from: NiHaoMike on March 30, 2019, 04:07:32 amThat was called "Power-line communication" aka. "Power-Line Carrier"https://en.wikipedia.org/wiki/Power-line_communicationWidely 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.

author: bd139
author_rank: Super Contributor
timestamp: May 08, 2019, 07:38:07 am
content: 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

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: May 08, 2019, 09:07:40 pm
content: Quote from: bd139 on May 08, 2019, 07:38:07 amBut 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.