We dug and refilled a 4000-mile trench to protect 9300 communications circuits against disaster (Apr, 1965)

We dug and refilled a 4000-mile trench to protect 9300 communications circuits against disaster

We split the continent with a trench four feet deep to give the United States its first blast-resistant coast-to-coast underground communications cable system.

More than four years ago when the first of 2500 giant reels of coaxial cable, started unrolling in New York State, we began an important project that will give added protection to the nation’s vital communications.

Today, 9300 circuits—available for voice, data, teletypewriter, telephoto—are included on this route. It stretches across 19 states and has 950 buried reinforced concrete repeater (or amplifying) stations.

Spotted strategically along the route about 50 feet below ground level are 11 manned test centers. Also of reinforced concrete, they have automatic air filtration and ventilation and living quarters stocked with emergency food and water.

This vital transcontinental link will serve the needs of government agencies, businesses and individuals.

This is a job that needed the Bell System’s unified research, manufacturing and operating capabilities. It is another implementation of a basic Bell System policy: “In communications, the defense of the nation comes first.”

Bell System American Telephone and Telegraph Co. and Associated Companies

  1. fred says: August 31, 200911:42 am

    We might all be dead but,by God,you’ll still be able to call your mom on her birthday…

  2. SteG says: August 31, 20091:33 pm

    Are we still using that Cable .. Is that why the internetz is sooo slow. 😛

  3. jayessell says: August 31, 20091:49 pm

    Those test centers are probably abandoned now.
    I’d like to see one.

  4. Charlene says: August 31, 20092:20 pm

    What exactly is the purpose of this ad? “This is why your phone bill is so high”?

  5. Firebrand38 says: August 31, 20092:56 pm

    Charlene: Look at the year. It was to reassure folks that communications could maybe survive a nuclear attack.

  6. Casandro says: September 1, 20092:04 am

    That’s coaxial cable. That’s kinda aincient. The only companies still using something like that outside are cable companies. So if you have cable internet, the connections of your neighbourhood are actually going over such cables.

  7. Firebrand38 says: September 3, 20099:54 am
  8. Keith says: September 6, 20099:00 am

    Likely a reference to that Autovon system built in ’63.
    Very interesting reading.

  9. Bubba says: January 30, 20166:19 pm

    That L-3 coaxial cable ran through Lamar, CO, which is in southeastern Colorado. There was also an L-1 underground coaxial cable between Lamar underground “manned test center” and NORAD in Cheyenne Mountain, much of the cable to Cheyenne Mountain was covered by concrete. There was repeater (amplification) equipment spaced every 8 miles that were in underground concrete manholes with bank vault type manhole covers with combination locks. The DC power for the repeater equipment was sent on the coaxial cable along with the telephone service, each of the manholes had power separation equipment to draw high voltage DC (thousands of volts) from the cable to operate the regenerators.

    Everything that was inside those underground “manned test centers” was shock mounted to improve the chances of the equipment surviving a nearby nuclear blast. The “manned test centers” were HUGE underground buildings that had quite a bit of equipment in them, including an Autovon 4 wire ESS and air-ground equipment to provide telephone service to certain Air Force aircraft such as Air Force One and SAC Airborne Command Post. The buildings had two floors with 16 foot ceilings, with a mezzanine for an administrative office on the ground floor and a breakroom/emergency kitchen on the mezzanine level. To give you an idea of the size of the building, the upper floor had a small vacant area in it for future expansion that was large enough to install a full court basketball court in it.

    There were diesel generators with fuel to last several weeks, there was an elaborate water well with pumping and treatment systems, and a septic tank system that was located inside the building, only the leach lines were buried outside of the building. There was a large cache of dehydrated and freeze dried food, I didn’t do the calculations for how long it would last, but my guess is far longer than the several weeks that the diesel fuel would last. There was an elaborate air filtration system, both for normal operation and under NBC conditions, there were several large blast valves in the ir filtration that would slam shut and isolate the building from outside air and force incoming air to go through NBC filters if the seismic detectors detected a detonation.

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