Have you noticed these antennas before? Driving by towers will never be the same for me anymore 🙄

Joined A T & T Long Lines in 1969 at Sweetwater, Texas. Worked on the Dallas to LA route and the Denver to San Antonio Route as a Microwave Technician until fiber optic technology was deployed. I had the task of shutting down most of the Transmitters and Receivers in our area after the traffic was shifted over to the fiber optics. After the final hurrah I then moved over to the fiber optics as a technican. Retired in 2005. What a ride, enjoyed every minute of it.

Let me add a bit to this story. AT&T was asked by Federal Officials to create a backbone of switches and transmission across the country which was "hardened" against nuclear effects and other events. Many switching centers were built underground and were connected by underground cables. A copper sheath covered them and things like toilets were put on springs to absorb shocks. Most equipment was hung on mounting hardware from the ceilings and not attached to the floor so it would swing when pushed. Diesel generators were provided with exceptionally large storage tanks. In general, the buildings were located outside major population centers since they cities were deemed targets. Here's a point which you can't see from viewing abandoned buildings -- the cost of all these extra construction expenses was paid NOT by the federal government, but everyone who used the AT&T system in the 1950s. AT&T was a telecom monopoly and the regulators deemed those expenses were justified for the overall good of the nation. If this was to happen today, since no telecom company would want to bake in the additional costs (making them economically noncompetitive), the bill to the government would be huge. Instead, your grandparents paid for this by adding a little cost to each call made.

About 10 years ago I was helping a buddy who bought one. It wasn’t this big, had the horns and fly swatter antennas. The main building looked like Monday’s crew shut the door and never returned. Log sheets were still on wall, the wet cell battery banks was almost dry. It was a true relic.

Some additional random facts about this fascinating system (I was with the Bell System at the time): Many of these microwave sites are still in use. They were supplanted by a coast-to-coast buried coaxial system (sometimes referred to as L-4) that had thousands of small underground bunkers along their routes that contained repeaters. These were extremely hardened to withstand nuclear blasts and contained several weeks of supplies so they could be manned, including special air filtration for fallout and even a Bell System incinerating toilet! Each of these repeater sites also had radiation detectors which, if triggered, would send a notification so the National Surveillance Center in New Jersey would know where there was a nuclear explosion. The Bell System supply catalog contained thousands of standardized parts they ordered to spec from suppliers, each with its own Bell System part number. They even had Bell System ashtrays! As for these antenna towers, the drawings for their construction anywhere near a likely-target for a nuclear weapon had fully 90% of their height under the surface to help withstand a shock wave knocking it over.

I work for the company that owns these sites now and have been inside a bunch of them. They really are bunkers and built very stout. Some of them still have underground diesel generators and stuff too. The coolest one I have been to is on top of a mountain just south of Salt Lake City, the access road is 7 miles long and is inaccessible during the winter. There is a massive steel helipad that is built off the side of the mountain and the only way they could access the tower during the winter was by air. Don't use the incinerator toilet though, it smells terrible.

It’s worth noting these towers carried more than phone calls (though that was their main use): the earliest live TV broadcasts, along with live radio, depended on AT&T Long Lines - and their microwave system was the fastest and highest quality way to get a broadcast from coast to coast. Compared to the older Coax cable systems, the capacity was MASSIVE, and upgrading it was as simple as upgrading individual radio pairs-laughably easier than Coax, where you have to replace the entire wire. Only Fiber had greater potential.

The long line was a genius “we done care what it cost” system. You could call Georgia to California and be routed through Canada and never k ow it. I know a fellow that worked around the long line system. He talked at length about the system and the radios for the presidents plane if in nuclear war. He remembers the stats and all kinds of tidbits that you can’t find on the internet. Going to be a shame when all those guys are gone.

In the 1970's and 1980's, I was a Microwave Transmission Engineer that surveyed and planned numerous microwave installations around the U.S. It was a great career until there was a change in technology. Although fiber optics was more expensive and difficult to install (because of the difficulties of getting right of way permission to bury cable, and actually burying cable in rough terrain ), fiber optics had the advantage of much greater bandwidth. The AT&T system described in this video primarily carried long distance phone traffic (besides military and government traffic).

As a retired AT&T Special Services tech, I can say that the general public has hardly a tiny inkling of all the weird infrastructure we had (have) out there. I recall being under a major city in a side tunnel between buildings that nobody thought were connected at all and spotting gear even I had no idea what it was and the placard stated that my group maintained it!

Read some of the comments and here are a few of my own. Complementing the nation wide microwave network was a nation wide network of coaxial cable, built by AT&T Long Lines, mostly underground, that was originally developed in the mid to late 30's but not deployed until after WW 2. It was called L-carrier and there were 5 variants. The first variant, L-1 operated at 3 MHz and had 600 voice channels on 4 coaxial tubes, and required repeaters every 8 miles. The last variant, L-5E, developed in the mid 70's had 22 coaxial tubes, operated at 66 MHz and had 13,200 voice channels, and required repeaters ever mile. Only a few L-5E systems were built. There were two coast to coast L-carrier routes, with many shorter routes connecting major cities, especially on the east coast. This was built as a supplement to the microwave system. The network was all analog, with thousands and thousands of audio channels, with about 3 kHz of bandwidth each, and used millions of vacuum tubes, and later transistors. Until the 56k DDS capability was added to the L-carrier system in the 1960's, data that was carried by the L-Carrier system was audio tones that were carried on the audio channels, and converted from and to digital data by modems. Basically what the customer got was a two way audio circuit that was brought into the customer's facility on two phone lines (one channel for transmit and one for receive), but was optimized to carry the audio tones created by the modems. The multiplexing scheme used single sideband frequency division multiplexing, starting with multiplexing 12 voice channels into a group, then multiplexing 5 groups to a supergroup containing 60 voice channels. 10 of these supergroups could be multiplexed into a master group of 600 channels. In the late 60's, equipment was designed that could use the bandwidth occupied by an entire supergroup (60 voice channels) to be dedicated to a single 56 kbit/s digital data channel. They thought this was high speed data back in the day! The L-4 system could multiplex six master groups into a jumbo group for a 3,600 channel system over 20 coaxial tubes In the early days of network television, TV channels were carried on the L-3 coaxial carrier systems as well, but it did not work as well as microwave as it had too much group delay. I believe one TV channel required the bandwidth of a 600 channel master group. This same multiplexing scheme was used with the microwave system. This was proceeded by a network that originally consisted of mostly open wire lines, and on some routes cables consisting of many pairs of thin wires contained in a cable within a lead sheath. Open wire lines are individual copper wires about #6 AWG, or 4 mm in diameter, strung on cross arms mounted on poles. The early circuits were open wire, but as time went on, some long cable routes were built as far west as Chicago, but most were the open wire lines you sometimes see in old movies. The reason open wire was used instead of cable is because open wire has much less loss than the thin wires used in cables, and needed far fewer repeater amplifiers. Railroads also ran a lot of open wire along their tracks for their own communications needs. These wire and cable circuits were made possible by the invention of the vacuum tube which could amplify or "repeat" the signals which would become very weak after about 150 miles of open wire. There were eventually two open wire routes built by the early 1930's through the sparsely parts of the country west of Chicago, the northern route and the southern route. This was done to increase capacity but also to increase reliability in case of damage to the facilities. These open wire systems also carried the radio network broadcasts coast to coast and border to border also, at voice frequency, but by the late 1920's a carrier system called C-Carrier was was designed that could impress 3 additional voice channels on an open wire pair at frequencies heterodyned above the voice frequency, for a total of 4 voice frequency channels per pair of wires, and later a carrier system was designed that could impress 12 additional voice channels above the voice frequency. But the radio networks continued to be carried at voice frequency on open wire until well after WW2, when they were eventually put on the coaxial and microwave networks. Hope this helps. Thanks for reading. You can search if you want more information.

One thing you missed is that many of these sites are still active. The microwave technology has been deactivated and replaced with fiber but still for the same communication reasons that these sites were intended for. Fiber optic can travel farther distances than these microwave towers. So the active sites are farther apart and many of the in-between sites have been abandoned and sold off. The AT&t long line team still exist and they still maintain and protect the network All over the United States and across the oceans.

My mother maintained the antennas in South Carolina for years. I would often have to sleep in them while my mother dealt with things at night. I even helped switch cards out in the large banks of electronics. I miss the blinking LEDs and the sounds of fans and relays.

Used the swiss cold war version built by Hasler during the coldwar period. Since all phonelines are underground anyways it was virtually indestructible and tamper proof and could run on its own power. The mechanical switches were beautifully engineered.

My dad worked on those sites in southern Oregon for 35 years until he retired. They were remote and not manned. My dad would often get called out in the middle of the night because something had failed. After they changed from vacuum tubes to solid state he would get called out less. I often would go with him on the callouts in 4x4 vehicles and Sno-Cats in the winter. He also worked on the Autovon (which was a 4 wire phone service) and Echo Fox.

It struck me when he said something about needing all the space for the equipment and now it fits all in a closet somewhere. Reminded me of the time my friend took me to a phone switch building and there was this huge room, about 100 square meters or more. The room used to be full of equipment. Now there are two server racks that do everything the whole room used to do plus internet.

Man I don't know what it is about the long lines towers... but something about them is so surreal and creepy. Probably because of their original purpose, but also the remoteness, abandonment, and claw-like antenna design. Nostalgia too.

Ahh, the good old ATT microwave long lines! Brings back memories from my early data comm days. We had lots of 9.6K analog links running around the country. You could track the sun by the outages in the spring and fall caused by "carrier fade". This was due to the wide temp swings during sunrise and sunset. Was a problem for an hour or so then would clear every time on it's own. Became much less of a problem when the switch over to 56K DDS circuits became available, same microwave system but much better error recovery.

One of our broadcast transmitters was housed in a decommissioned one outside of Bakersfield on Mt. Breckenridge. There was a sign by the exit - "Please keep the door closed to keep the rattlesnakes out."

I worked at a facility like this one, but smaller, just out of town inLodi California. The building had no windows, and was pressurized slightly to discourage the outside dust from the surrounding agricultural area, and a commercial nursery from making its way inside. It also had an underground cable vault and another room that was used as a lunch room. The name Autovon sounds familiar to me, so I guess we had that. I, along with others did installation work for Western Electric in that location.

Very cool! I was able to tour around the inside once on a site survey for a previous employer. It’s dirty, dusty, mostly empty, and dark. Some of the outside doors were welded shut to simplify security. But it sure is a cool site.

I’ve been inside two of these facilities as a field service engineer. All the fun stuff was decommissioned ages ago with maybe 20% of the floor space now occupied with modern gear. I can only imagine what they looked and sounded like in their hay days.

The amount of software behind this was staggering too. That software allowed us to route around any failure at all. If there was a physical way to make a connection it would work. Throughout the 1970s, 1980s, and even deep into the 1990s that software continued to improve to reduce both cost and reliability in both catastrophic situations and also general faults. Look at what happened on Jan 15, 1990. A serious bug caused massive failures but the system still managed to make even more successful calls than a regular day. Netflix "created" chaos engineering but similar concepts existed in Bell Labs in the 1970s and 1980s.

today, AT&T's system is down, and KZfaq serves me this video.

I got to work on one doing a project for AT&T wireless about 15 or so years ago. It was wild not like the typical locations we would work although I have been to some pretty unique places. This particular location was about a hour from NYC off of I-95 in Connecticut. So we get there and go through the gates. There is a large orange and white striped tower with the old horn dish microwave antennas. We pulled up next to the only structure we had seen which looked like some sort of shed and that seemed strange as hell but whatever. We took a look for more info on our computer and we had no more information on where our equipment was located. So we jump out and look around and it makes no sense this small shed that we had no access to. They must have had some cameras around because the shed door opens and we get greeted by a armed security guard at the top of stairs. We were already taken back because we had no idea the shed proceeded underground. The guard was very nice and escorted me and my partner to the 7th or 8th floor on the cargo elevator. The floor we arrived on was mostly filled with switching equipment but everything was very secure and decided by security doors and card locks. The area we went to was just a small room with our mobile BTS equipment inside. I looked around though on that floor and everything was on or hanging from large industrial springs and looked very dated. I realized how special this place was! It was amazing and nostalgic to say the least. This place was so inconspicuous from the surface people have no idea what exists there.

I’ve worked in one of these from the Cold War. It had decontamination showers at the entrance and a room that was still stocked with Geiger counters and dosimeters that were labeled with some kind of civil defense logo.

AT&T Long Lines first cross-county connection (NYC to San Francisco) was completed in 1948. Carried early United Nations meeting in San Francisco. Chicago to Omaha section closely follows US 6/Interstate 80. In 1980s, while in Graduate College at Iowa - met the AT&T Fiber Optic crews laying out its replacement.

There's a repurposed Long Line tower at Evangola State Park in Evans, NY. Over the last 20 years the horns had taken damage, then were removed and replaced with cellular arrays. The tower itself is has a nice patina but still stands strong. Up until this video, I never really knew what they were. I knew they were microwave but wasn't aware of that they did. Thanks for this video!

I've been in Turquoise station a good number of times(and others), I installed the original VZW(may have still been airtouch) cell in the late 90s when the sites got sold to American Tower . It's one main floor at ground level(those double doors facing the drive up) there's a smaller upstairs area where the Autovon stuff was and the basement is the footprint of the taller portion of the building. DC plant/batteries were down there and the generators on the side facing the tower. It's funny, the one cell in there tucked in the corner near the tower with the plastic curtains you see in in big freezer doorways and a big mostly empty and dark room. The old fluorescents are barely working, many of them dead or flickering. One of the cool sights is the big status panel with a bunch of frosted plastic or whatever indicators for the various building systems. You can tell it's been broken into a few times, copper thieves. It has a full sized freight elevator to the basement right by the double doors, disabled though and the doors screwed shut. By the door there's asbestos warnings and an old asbestos survey report with alarmingly large numbers, though I don't know what's acceptable. Another stairway leads down to a shelter area, looks like a 50's break room but lots of cabinets, presumably for supplies. As far as I could tell, that area and the rest of the basement weren't connected/accessible from there. It's been a couple years since I've been in there but the tower has gotten worse, the cornucopia dishes were just wobbling in the wind but still in place, waveguide long gone. That one laying over wasn't like that. The cages around the missing waveguide were swinging in the breeze and several were on the ground on the shotcrete below the tower, a little mangled from the fall. Keep your distance from that tower, all those pieces are heavy.

I’m not old enough to have installed these but I’ve decommissioned a few in my tower climbing career. I was always fascinated with the older technology on site. I always loved a good mountain site because they usually had plenty of old tech.

From someone who works on the towers, these have always intrigued me. Having taken several down you can appreciate the engineering they put into them. Some of the widest towers I've been on and the coolest rigging.

Downtown San Bernardino, CA had these on top of an old AT&T building with no windows. Probably one of the tallest and widest buildings in that part of the city. I never knew what those antennas were for until this video and I've lived there my whole life. They were actually taken down about 3-4 years ago.

so glad you and Mike got to meet, he's so much more knowledgeable on the tech side of the system. I was better at trespassing, glad y'all avoided that hah.

So i showed this to my dad. He worked for Collins Radio eventually Rockwell then went to work for Andrews that had the red lightning bolt looking icon on their towers, horns whatever. I was hoping to get a little more information from him but hes up there in age. He smiled and laughed, "yeah i installed stuff like that".

Back in the day, these towers also distributed network television programming to the local TV stations. They would often mount a dish lower down and offload the signal to a TV tower in the area. Not only fiber and the need for greater bandwidth killed them off, but equal access as well. The towers were atop large multi-story AT&T/Local Bell (and sometime Independents) buildings and smaller buildings in quieter towns. Those switching offices were classified as either Class 4 Toll, Class 3 Primary, Class 2 Sectional, or Class 1 Regional. These switching offices were interconnected by intertoll trunks carried over these microwave paths. Long distance trunking carried the bulk of the traffic. As well, there was "data" in those days such as special service circuits, private lines, teletype, radio networks....all those NFL and college football games we enjoyed - rode over the long lines network. These towers were also found in very remote above and below the ground AUTOVON sites which served the Military through their own stand-alone voice network. With the advent of fiber, deregulation and equal access, the functions of the CLASS 1, 2, and 3 switching centers went with the wind in the '80s and early '90s. The buildings were vacated and sat dormant for years. Many in those cities have been sold off to house data centers. Most of the towers that were situated between switching offices (repeater sites) were sold off to American Tower, who dismantled the waveguides, in some cases removed the horns and presently lease space on the structures to mount cell antennas. The last functioning Long Lines route I'm aware of was recently decommissioned between Montgomery and Dothan, Alabama. In recent years AT&T has been removing the towers from the buildings they own.

I worked for AT&T as a programmer back in the late 80's. Our manager got us a tour of the underground site at Dranesville, Virginia. It was pretty amazing what they had under there. No pictures though!

Back in the 80s, my dad worked in the Netcong bunker in NJ. It handled.... well, a lot. A couple of times, we got to go into the bunker with him to look around. I've got faint memories from the visits. At that time, the site was accessed by something that was more of a double track trail through the woods than a road. The trail sat tucked in a quiet little suburban neighborhood with a lot of trees. You drove up and over a hill into a clearing in the forest where the lot and surface buildings were. One building had a stairwell that took you to a hallway with doors at each end. The hallway had decontamination facilities as you walked down it. I remember then doing two 90 degree turns to go down another long hallway where a guard sat behind glass. I'm pretty sure that glass was bullet-proof and he had a hole that he could shoot down the hallway from. Once through, there was a massive blast door that held all of the equipment. That's as much as I remember. I think it housed the hardware for the NOC in Basking Ridge too. They remodeled the NOC and our family got invited to a family night after the work finished. It had around 3 rows of 25 screens if I remember right. To show off, they put Top Gun on each screen. So I was able to go to school the next day and say I upped my number of viewings of Top Gun by 75 in one night. Fun times. On a side note, my grandfather worked for Bell Labs/AT&T. Put in the system out at SAC when my mom was a young girl. She and her sisters tell the story about the red phone that they had in the closet that they would charge the neighborhood children to see because that was a pretty big deal then. When we all lived in NJ, he worked in a research facility that had a quiet room. That was cool to experience.

I used to patrol 365 miles of Fiber Optic lines in the 80's. I actually went inside one of the microwave towers in Windermere, FL. They are useless in heavy rain as it bends the signal to the ground. That is why they had to have so many so close together, and curvature of the earth. There are huge blast doors inside about 20 feet underground. We still have one in downtown Columbia, SC but is decommissioned. The waveguide horns are around 4500 lbs each. Fiber Optics replaced all of those and multiplied the capacity of the system by thousands. If a fiber optic line is cut it costs AT$T thousands of dollars a minute when they are down. In the 80's most of the cables were 13 pair and cost over $25,000 to repair. We patrolled to intervene in case someone got too close digging. Most patrolling is done by airplanes these days.

As an alum of Andrew, I have to say that microwave with the red flash is just as beautiful as the old horn. But also an alum of Bell Labs I can’t believe I had never heard of Autovon. For that and the whole tour - thank you gents.

There's a bit more on the defense side. Back in the late 50s, through the 70s, there was the SAGE network, used to track incoming bombers. This included several radar stations around Canada & U.S., connected to IBM computers. In my work for a Canadian telecom, back in the 70s, the area I covered included several radar stations in Ontario, which were part of the Pine Tree line. Later on, the mid Canada line and DEW line were built further north. The company I worked for carried the SAGE network into some locations, though Bell Canada had most of the circuits. BTW, you mentioned massive structures. The company I worked for had some microwave systems up on the CN Tower in Toronto and my work occasionally took me up there. For many years, it was the tallest free standing structure in the world.

My dad worked in Long Lines for much of his career in AT&T / The Bell System. Nice video!

I'd like to clarify something. Before 1984 all toll facilities in California and Nevada were owned and operated by Pacific Telephone and Nevada Bell. After the break up of the Bell System, AT&T Long Lines aquired all of toll facilities nationwide. My dad was working for PT&T and then on 1/1/84, he was suddenly working for AT&T! Another clarification, the Long Lines division of the Bell System was started clear back in 1911, when the need for long distance service was realized. The only facilities back then was open wire lines, coax cable and microwave radio wouldn't come along until the 40's and 50's.

Amazing that this video stumbled across my feed. There’s one of these horns out by a hiking trail I love and my mother asked me what it was one day. I assumed it was a microwave horn antenna just by looking at it from miles away. Told her as much, told her it is probably for some old point to point military comms or something. Then this video pops and and I go check on a long lines map, lo and behold, it’s on the map. Had no idea I was so close, haha. Didn’t even know this network existed until now!

I think the former AT&T location in White Plains, NY, back from 1960 had these horn antennas and was supposed to be bombproof. A friend of mine worked there and in 1987, he had a letting with permission to show me around with another friend, we were all amateur radio operators. I saw the big relay banks there. I used Autovon in the US Air Force and later in Civil Service.

In many mountainous parts of Colorado, people use microwave for all telephony and internet. I sat next to a guy on the plane who maintains them. He was like 70 years old and still consulting. Apparently the expertise is in short supply

In the UK we had something similar but predominantly on tall round concrete towers. The towers still exist to carry other communications but they lost their microwave dishes after the system was decommissioned in the 90s.

I grew up about a mile from one of these stations. It was also EchoFox, Combat Ciders and the western terminus of the L5 network. In elementary school, the father of a good friend worked there. He took our class on a field trip. My 10 year old self did not realize how much information passed through that building. Great video.

Found a few of these in New Mexico while out exploring some of the public national forest land/random county roads. There was one in particular on top a large hill, only accessible by 4x4 with high ground clearance. It was tucked in and hidden but with antennas visible from the road. The building itself was very bunkered and had cameras ALL over it

hi great vid!!! I started building towers in mid 90s. These were also microwave backbone sites that all telephone companies used up to a point....I do know taking them down was interesting....some of the antennae we did alone weighed almost 7 thousand pounds ....the structural steel side of it was insanely engineered and crazy heavy....a lot of them were stripped to allow for newer technologies or just to shed weight for wind loading...anyways cheers!!

Super funny that this is recommended to me after ATT going down yesterday

When I was a young officer cadet in the Canadian navy in 1981 we would use autovon to call home as it was free v. long distance. You could call any base and then ask the operator for an outside line.

When I got out of the Marine Corps in 1968 I went to one of those underground AT&T facilities to apply for a job. They gave me a tour of the place and said that it was built on super-size springs to absorb the shock of a nuclear bomb. They had enough water and food for everyone in the facility to survive for 2 years.

I love Spencer Harding's photos of these towers

The majority of the communications links were carried by buried cables called L4. Microwave links were used to route links off the main buried cables and to route around sections of the cable that were knocked out. Every 150 miles or so there was a Main Station that monitored its section of cable and took care of maintenance activites. Many of these were underground bunkers designed to survice a near hit of a 20 MT ground burst at 2 miles. Specific Main Stations contained large AUTOVON switching systems for the military and also contained facilities for phone to radio patching of presidential aircraft communications and airborne military command aircraft such as LOOKING GLASS and its airborne back ups.

@BartlettTFD • 2 minutes ago These sites were owned and operated by AT&T Long Lines. They provided the country's microwave backbone prior to the advent of fiber. The layout was as follows: 12 voice channels = 1 "Group". 5 of these Groups comprised a "Supergroup" which was 60 voice channels. 10 Supergroups = 1 "Mastergroup" which was of course 600 voice channels. These "Mastergroups" were wired to a "FMT" ( frequency modulated transmitter) which modulated 1 channel of the microwave transmitter. At the receive end, it was exactly the same except it had an FMR, FM Receiver. As I recall, their were 10 microwave channels, A, B, C ,D,E, F,G,H, + X, and Y. X & Y were the protect channels and would not be used unless one of the channels failed. When I was involved, I worked in tv network transmission. 4 of the lettered channels were assigned to NBC, CBS, ABC, PBS. (FOX didn't exist back then.) I would use "X" & "Y" for NFL games which was risky since it left no "protection" channels available in case of equipment failure. Weekends were really crazy back then, with multiple switches occurring to make sure the right tv station got the right NFL game! An exciting job!

If you can find a group of retired telephone company central office technicians they might know someone who worked on that technology. That was from the days when a 56K data circuit was state of the art.

This exactly what i wanted, thank you for the information!!

Years ago I used to service the repeaters for BellSouth (one of the baby bells, was AT&T before and after) and NORAD apparently monitored those towers. Whenever I entered the building it would immediately trip an alarm, I had to make a mad dash and try to find the secure dialess phone or intercom panel within 30 seconds or so, where ever it was (they never seemed to put it anywhere close to the entry door) and pick it up and announce to them who I was and give them the code that was unique to that location, before they had time to summon the police or sheriff out there. To make it extra challenging, sometimes I was unable to get the lights to turn on in the building and there are no windows to let in light, and I forgot to bring a flashlight, and you absolutely didn't leave the door open more than a few seconds. One of the sites locked me in and I couldn't get out right away as I was bringing in test equipment to work and one of the bell guys had to come let me out. I never knew what to expect going into those sites. Also, aside from the tower sites, there were many underground bunker sites for underground cable systems, and occasionally you can find them along the path in city tunnel systems, like subways, coal and utility tunnels but most of them have either have been abandoned or repurposed.

My wife and I both were recruited Pacific Bell out of the Military to work in the LA area. She worked in the Madison Complex, the downtown building you showed a picture of. After eight years I transferred to Nevada as a Microwave technician and wound up going into several of the long line buildings along with many other microwave buildings in Nevada which were built to transport phone calls across Nevada to the Rural towns, some sites were on the top of mountains over 10,000 feet tall. Each month we had to do FCC required frequency and power checks and document our findings in our log books.

My old bands practice room was in one of the old switch rooms for the long lines in down town Tucson. Never knew it until recently after seeing another video on the subject. I just thought it was the old local phone company. Was always curious why the building was solid concrete. But it was perfect no cell phone service since it was essentially a faraday cage and play as late and as loud as you wanted without bothering anyone.

I can appreciate a hobby that isnt very common. I like to look for NGS Benchmarks. Saw this video and was like....that mt is the perfect place for a benchmark...sure enough it has one. Maybe some day I'll go out there to take a pic (assuming its not off limits). thanks for sharing this.

These microwave stations also used TWT (Traveling Wave Tube ) vacuum tube amplifiers between receiving and re-transmitting antennas. They just happened to be quite EMP resistant.

Full nerd time: FYI the low bitrate communications used the LPC codec (I believe the prime example example is the STU I/II/III) which were designed to be intelligible on a low bitrate line with a high bit error rate (up to 5%). The phone you showed was a digital non-secure voice terminal (ta-954) which was a relatively inefficient codec caller CVSD that was easy to implement at low cost, though used 16-32 kbps as opposed to the 2.4 kbps of LPC. My dad worked on LPC so I figured I should give a shout out :) The DNVTs are pretty cool but were used primarily for tactical communication.

Thanks for sharing this! Such a cool engineering project.

So….cool! And so happy to learn I’m far from the only one who geeks out on obscure stuff like this! Thx for posting!!!

Fascinating. Never knew these existed. Thanks!

I got to work on one of these sites surrounding Washington DC meant for the continuity of government. It was significantly more hardened than this facility but that's all I can say about it. There were a lot of other sites on steel towers including some that were used for SIGINT that everyone knew about but were supposed to be secret. Hidden in plain sight...

I have been intrigued by Long Liines sites for quite a few years and I always look for them in my travels, especially here in the Southwest. Sadly, a lot of them are being dismantled. There was a tower 10 miles south of my house that was totally dismantled shortly after I moved in about 10 years ago. It was on US Forest Service land and I suppose that the Government wanted it gone for some reason, and I never got to explore it.

Thank you! I live in Rome Georgia and never knew what that "weird" building downtown next to the Hardee's, that is so pristine and immaculately clean, actually was. Good information. Not exactly sure why, lol, but this was a very satisfying video. Great job.

Saw one of these driving in NJ earlier this week. I thought it was a siren not an antenna...very cool to come across this video so soon after seeing one in person

Would love to see inside one of these facilities!

That was very cool! I’ve seen some towers like that, and never knew what they were

So cool! I always remember passing by one as a kid and thought it was a radio station. So cool to see what they actually are.

As a kid back in the day, I imagined the horn antenna as seats for the gods. Started working with microwave radio in 79, and really appreciated them

There’s one of these on saddle peak above Malibu, concrete tower with steel platforms, big concrete bunker. Never really thought about it being a hardened structure from the cold war.

Incredible! I went to college in Ellensburg, WA, and one of the only forms of entertainment was four-wheeling up to what we would call "the cell towers" on North Umtanum Ridge. Looks like I'll have to also call it "the Weymer Long Lines Site."

Thats so cool! We have a tower here In Champaign IL and as a kid I always wondered why it looked so different from any of the other towers in there area!

I was an air traffic controller at a regional facility known as an ARTCC. Early in my career we had the remnants of old cold war tech. Our phone system was old hard wired copper, and we had several lines labeled LL. I'd heard the term Longline, but never knew what it was until now! If you like this cold war tech stuff, you should investigate the ARTCCs. There are 20 of them around the country, all still in their original 1963 buildings (with a lot of mods). They were all located in semi remote areas to avoid nuclear damage. We had a hardened basement with cots and C-RATS in case things got hot. Also had an HF radio on site! Lotsa cool history and stories for another vid ;-)

I grew up next to one near Moro, Oregon. It was eventually taken down. Had thick concrete walls, massive batteries, and a huge diesel generator. Always was a creepy looking place when I was young.

Underrated channel!

This was very interesting. Thank you.

About ten years ago, I got to take a tour of one of these that was being partially retrofitted to be a data center. Located in Boone County Iowa, this facility was mostly underground, with only a small surface entrance. The building below was massive, easily big enough for a basketball court. The guy who was turning it into a data center made the decision to keep a few of the areas as they were, including a recreation/lounge area, and the most late 60s/early 70s public restroom you've ever seen. What made this especially cool for me is that my Dad was one of the plumbers who worked on the facility when it was being built.

I own an auto repair shop right next to an old At&T switching building. I’ve been here for like 15 years and the building houses one of these huge long line antennas, I always sort of ignored it like the backdrop of telephone lines. Just recently, I was given a tour inside the building and also got to see the underground bunker. What blew me away was the size of the switching building. It was designed to handle over 100 people at a time; huge cafeteria, huge bathrooms. Now, there is one guy operating the building. He showed me all the different floors, first floor dedicated to generators and a huge bank of back up batteries, two entire floors dedicated to switching phone lines and then the top floor, which was extremely empty, one corner of it being dedicated to the entire areas fiber optic communications. The tour of the bunker was really cool too, it was a bunker essentially built into the side of the mountain we are on. It felt very coldwar’ish. Glad I saw this video now explaining its purpose!

I’m pretty sure there is one sitting on MD Rt. 140 in Finksburg, MD. Still intact, painted red and white. It’s been there as far back as the ‘70’s that I remember. Probably much longer.

That high pitched whining noise when you are near the antennas is very noticeable

The facility where I worked, (Early '70's), had a decontamination station at an entrance. We also had tower material stored so we could erect a replacement tower in the event the above-ground equipment was lost in a nuclear blast. I transitioned to the fiber optic world when we phased out the Terrestrial Microwave system.

As someone whos obsessed with towers, it could be any tower, radio, tv, cell, communication. Im glad there are others and makes me happy

The British version was called Backbone, and mobile military communications systems that emerged from bunkers after nuclear strikes was called Conrad .

I grew up with one of these towers just a few miles up the hill from me in Kalama, Washington. So cool to learn the history.

I remember noticing them and being fascinated by them when I was a kid. Between 68 and 78 I lived out around Trenton New Jersey and used to spot these towers, painted red and white. My dad kind of explained what they were but it all went over my head back then. Last time I went out that way I still saw some of them around and I think I might go back with my drone to get some shots. I might even make a video of various kinds of towers... Now I live near AT&t in Holmdel/ Middletown New Jersey. They have something called The big bang horn antenna on display out behind one of the buildings. Maybe I should include that...

Only 30 subscribers? We had similar microwave telecommunication antennas in Czechoslovakia. I rent my electronics lab in the telephone exchange building from where the antennas were fed. The large grey parabola antennas were mounted on the nearby high-rise building.

I remember seeing these as a kid driving from Mass up through NH on I95/I93. I haven't seen any in decades since moving to Oklahoma and now Texas.

I work at one of the former stations. Walk past the blast doors regularly. This was cool man. Thanks.

This is incredibly fascinating!

I've been inside some of those sites and wow what a time capsule! I have some pictures of old badges and the blast doors.

Saw a few of these in Rome earlier this year, cool to see what they are all about. Great video!

I have a 250+ ft tower just up the road from me. It’s been there since after WWII. There was also a lead encased phone trunk that ran along Lake Erie on the ridge until the late 1970’s and there is also several telephone coax cables that run 4 ft down across the county south of me. Lots of Cold War left overs if you know where to look.😊😊😊 DE N2JYG

I have a vacuum tube that was used for this microwave technology. It had to be specially designed and constructed to work at these microwave frequencies. It is heavily gold plated and screws into a waveguide. High tech back in the late 1950s.....

I grew up near the Long Lines tower in Redwood City, CA. Super cool piece of history.

You have no idead how long ive been waiting for somwone to make a good video on this