Construction of the AT&T Long Lines "Cheshire" underground site

https://coldwar-ct.com/Home_Page_S1DO.html

by walrus01 • 2 years ago

216 87 2 years ago

metadat2• 2 years ago

Clothing was available for contaminated workers including dozens of boxes of brand new Converse sneakers, c. 1968!

Why would the workers be contaminated?

Struggling to understand the purpose of this station, at the top it says coax but why all the fancy cooling and contamination protection?

space_fountain• 2 years ago

These facilities were designed to be hardened so as to survive a nuclear war. The air intakes were presumably needed to provide cooling for the communication equipment inside and decontamination was for any workers who needed to visit after the outside has all been contaminated with nuclear fallout

BoorishBears• 2 years ago

First lines:

The Cheshire ATT facility is an underground complex originally built in 1966. It was an underground terminal and repeater station for the hardened analog L4 carrier cable (coax) that went from Miami to New England carrying general toll circuits and critical military communication circuits

Critical military communication circuits implies it was meant to survive a nuclear attack.

diggernet• 2 years ago

The site was built to survive a nearby nuclear attack.

nrr2• 2 years ago

This facility is what's called a tandem office in the old long distance telephone network here in the US. The idea was that it formed a link in a routing chain between two end offices when a long-distance call was placed.

Cheshire, CT, also happened to be an AUTOVON site, which carried with it military and national security significance. This is why it was hardened against nuclear attack, including the air handling augmentations, decontamination shower, gamma ray detection equipment, and so on.

bregma2• 2 years ago

You mean "couldn't they just reboot the server remotely using the terminal on their Mac after the crazed fools in the White House and the Kremlin annihilated civilization through nuclear holocaust in 1968?"

Well, all I can say is thank goodness we're not in that situation today so that people don't understand the "why"s.

Aren't we?

082349872349872• 2 years ago

That background though... ( https://img1.wsimg.com/isteam/ip/da3386ad-a465-4e41-834e-354... )

pixelesque• 2 years ago

MIRV re-entry test...

msisk62• 2 years ago

Those MIRVs come in kinda fast: https://www.youtube.com/watch?v=3ZM3y5qpMgY

dredmorbius2• 2 years ago

Mach 23, as noted toward the end of that video.

LargoLasskhyfv2• 2 years ago

In fully glory: https://en.wikipedia.org/wiki/Multiple_independently_targeta...

Animats• 2 years ago

That's an AUTOVON switching center.[1] There were at least 38 of those centers in the US. They were located in places some distance from major cities and military targets. They were hardened telephone central offices, but with many more redundant links between switches than the commercial system. So this system really was intended to survive a nuclear war.

The technology was Western Electric's 1ESS (#1 Electronic Switching System), and all 4-wire out to the handsets, so that conference calls would work clearly without feedback. 1ESS was a very bulky system. It was basically a pair of large mainframe computers running a big dumb switch fabric. The switch fabric is analog and electromechanical, using reed switches with a ferrite element so they stay in the last state to which they were set. That's why these were such big installations, even though they didn't have a huge number of lines.

[1] http://autovon.org

metadat2• 2 years ago

How deep did they bury the wires?

Were they run full depth from point to point?

walrus01• 2 years ago

Google "L4 transcontinental cable", but the majority of the long lines network was the famously known horn antennas on towers for FDD microwave point to point links in the 6GHz band.

jcrawfordor2• 2 years ago

It would vary by terrain and land use (e.g. agricultural), but generally just 2-3 feet deep by vibratory plow. Deeper emplacement and directional drilling were used as required to handle obstacles. For most L-carrier the entire en-route infrastructure was below ground, but it was more extensive than just the cable, with active repeaters in manholes required at 2-mile intervals for L-4. L-4 also required an "equalizing repeater" about every 50 miles, which was installed in a manhole but had a shed on top to facilitate technicians adjusting the equalization. Main stations, such as this one, were required every 150 miles.

fmajid4• 2 years ago

I’m surprised they didn’t use crossbar electromechanical switches for EMP resistance.

Aloha3• 2 years ago

They did - it wasn't all ESS

http://autovon.org/wp-content/uploads/2018/01/BELL-LAB-RECOR...

jcrawfordor2• 2 years ago

These AT&T facilities were hardened against EMP to the era's military design standards, and AT&T participated in validation experiments using both actual nuclear detonations and EMP simulators. I've never seen any indication that AT&T thought the electromechanical switches had an advantage in this context, but it's an interesting question if they performed any evaluation. In general, though, EMP protection was done at the "envelope" of the facility, and equipment inside of the facility did not need to itself be EMP hardened. Hardening of the facility was achieved mostly by a shielding system embedded in the outside walls, and of course AT&T had already performed considerable research into suppressing transients on the outside plant due to lightning.

Crossbar switches were indeed in use in the AUTOVON network for simple scheduling reasons, a number of AUTOVON switches were installed before the 1ESS was ready. Eventually all of the 5XBs were replaced by 1ESS. Some Automatic Electric switches were used at AUTOVON sites outside of Bell territory, these were at least semi-custom (AE just called them "the AUTOVON switch") electromechanical machines.

kev0094• 2 years ago

The entire underground structure is an engineered Faraday cage constructed from a tremendous amount of steel rebar, copper mesh, and a central grounding and bonding network.

Aloha3• 2 years ago

They also had Number 5 Crossbar switches as well, the switching fabric wasn't huge in size, like I've seen what the frames look like, ESS was still much smaller than the crossbar that preceded it, and not that much physically larger than a comparable 5ESS

kev0094• 2 years ago

The underground sites were primarily for Long Lines equipment, i.e. L-carrier Coaxial repower, regen, cross-connect and HVAC and power continuity for these. You can see in the illustration that switching at its least efficient was maybe 1/4 of the facility (lowest level), L (and TD MW) would be a bit more dense but similar floor space on first level. These multistory sites had a lot of extra room for training rooms, service bureau, and some nod toward continuity in terms of sheltering a number of people with some token supplies although if you look at enough pictures over time it doesn't appear like it was ever taken very seriously... ultimately I think these just turned out to be a way AT&T and the DoD came up with to get the US Government to more heavily subsidize Long Lines network construction.

Switching of copper end lines would often happen closer to the user, i.e. on base although some sites did have switching due to favorable proximity (i.e. Soccoro, N.M) or presumably function like a tandem (maybe this site?). You can see a little of a 1A ESS in this video (https://www.facebook.com/CheshireVolFireDept/videos/a-brief-...) and maybe some 5ESS in the background as well although it is too brief for me to tell.

Some undergrounds were dual purposed for Microwave pathing and cross connect (like this linked one), but most microwave was instead in above ground hardened facilities elsewhere for path diversity.

Some undergrounds had Echo Fox transceivers and switching http://www.coldwar-c4i.net/Echo-Fox/index.html.

Project Offices are an interesting related rabbit hole to pursue http://www.coldwar-c4i.net/ATT_Project/index.html.

Source: I own an L-3 regen bunker and have done a lot of research on them.

marcus0x62• 2 years ago

and maybe some 5ESS in the background as well although it is too brief for me to tell.

The frame at 2:22 looks to me like it has a 5E in view.

leoh• 2 years ago

Why was there a gamma ray detector?

nrr2• 2 years ago

Gamma rays are an early danger from the fallout from a nuclear blast.

kev0094• 2 years ago

Gamma rays also travel faster than the other destructive waveform. Much of the expansive destruction from a nuclear bomb is due to "over pressure", and these facilities have spring loaded blast valves that quickly snap shut when signaled via the gamma detector or a manual control to limit it from entering the protected zone.

Bunkers have different grading in terms of blast resistance and most of the AT&T bunkers were engineered for something like 5, 10, 15, or 20 mile air burst strikes of certain warhead yield.

The AT&T bunkers are mostly far removed from population centers such that a direct nuclear strike would be a waste of a perfectly good nuke. In reality, a directly targeted conventional warhead or sabotage would be plenty effective in causing major service disruption so I think a lot of the realities for survivability would be aftermath repair capabilities.

Lammy• 2 years ago

This other page goes into a little more detail on the detection system: https://coldwar-ct.com/Blast_Detectors.html

“Most sites included Gamma detectors that were designed to detect the radiation wave as well. They were redundant systems, any detection, overpressure or Gamma would button-up the site at which point signals were sent to all Continental U.S. sites that a blast was detected, where it was, the size of the blast and wind speed and direction. Sites within 250 miles of any detection would go to Auto-Lock down.”

jeffbee2• 2 years ago

I wonder how sensitive they were/are. Can you goof on them with a portable medical gamma ray source?

VoidWhisperer• 2 years ago

Likely having something to do with this being a bunker meant to effectively endure a nuclear attack

baliex• 2 years ago

As a Brit that map at the bottom is very confusing. A Bristol not to far from a Glastonbury, ok yeah, that makes sense but the map mustn't be north-oriented. Oh, and what's Manchester doing so close to Glastonbury, and that's not where Durham would be, or Norwich, or New Haven. Hmm.. and I didn't think we had a _New_ London.

https://img1.wsimg.com/isteam/ip/da3386ad-a465-4e41-834e-354...

Also, Cheshire is a county in the north of England so the whole article was very confusing from the get go as to where this station was located. Here it is on Google Maps: https://maps.app.goo.gl/aEWT2L6QYqntYDDz5

Bolton, Kensington, Oxford, Coventry, and—slightly left field—Berlin are also nearby.

Retric• 2 years ago

The 42 degrees north goes through the northern US and northern Spain, but is well south of England. https://en.wikipedia.org/wiki/42nd_parallel_north The New is also a hint aka New York, New Jersey, etc.

It’s a map of Connecticut, USA.

willwade• 2 years ago

I'm with you. I started reading and was like "wait.. this is not the Cheshire I know of - where has this been hiding".. Then on the map: Lebanon and Brooklyn.

Also Wallingford. I bet thats nothing like the Wallingford I know of (Oxfordshire Town)

qingcharles2• 2 years ago

So many places in the USA have matching British names I had to check to see if Brooklyn was one of them, but looks like it's named for a Dutch town, which makes sense.

worstspotgain3• 2 years ago

That's why it's called New England. Here out west, most of the anglo town names are the names of settlers (with exceptions like Richmond née upon Thames.)

PietdeVries• 2 years ago

I stared at Google Earth for a while, using the 41:30 and 73 as a guide, but wasn't able to pinpoint the location of the site. With these huge vents, it shouldn't be too hard to find where this site was located.

Anyone an idea?

worstspotgain3• 2 years ago

Well we wouldn't want the Russians to find out too would we.

jonotab• 2 years ago

https://maps.app.goo.gl/SpeEBjSmiDFAeqr17

wil421• 2 years ago

There’s a reason they call the area New England. New York was New Amsterdam before the Brits took it over.

sdwr• 2 years ago

Old New York was once New Amsterdam...

mindslight• 2 years ago

Zoom out a bit and you get a whole bunch of Manchesters, and none of them had a Factory Records.

fred_is_fred• 2 years ago

Would guess you don't have a Mohawk either.

rob2• 2 years ago

Wait until you learn we here in Connecticut also have hundreds of miles of stone walls, just like England!

mrguyorama• 2 years ago

https://www.reddit.com/r/mildlyinteresting/comments/8o6xc5/r...

This sign is just for the singular state of Maine. Notice the two distinct "Sweden"s, and that ignores "New Sweden" we have way up north.

The colonists were not creative with names.

singleshot_• 2 years ago

Wait until you find out how to correctly pronounce “Worcester.”

mike503• 2 years ago

Anyone else in awe at all the infrastructure, systems, etc that were setup especially due to the Cold War? Things like Operation Looking Glass, keeping a staffed plane in the air, 24/7/365 for nearly 30 years, all these kind of hardening projects, it's crazy to me how much work and how many decades it spanned.

And that's just the stuff we now can openly read about. I can't imagine all the systems and redundancies in place right now... but probably a lot more digital with analog backup only.

fmajid4• 2 years ago

Construction of the AT&T Long Lines "Cheshire" underground site

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