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AT&T Long Lines

Barnett, MO Long Lines site

Shortly World War II, American Telephone and Telegraph Corporation — AT&T — began work on a nationwide microwave relay system spanning from New York to San Francisco. By the 1960s, AT&T's Long Lines, colloquially known as the "Telephone Skyway" or "Skyway," would be responsible for transmitting long-distance telephone calls and television broadcasts throughout the United States and Canada.

To accomplish its mission of a coast-to-coast telephone and television relay network, the Bell System constructed hundreds of towers dotting the American landscape. Some sites were located in large central offices (which served as the telephone switching hub for the city it was located in) several stories tall, others were unmanned sites in the middle of a cornfield in Missouri, and some were buried underground to protect itself from attack.

As a sign of the times when the Long Lines system was constructed, many sites were semi-hardened, hardened or even underground to keep the system online in the case of a nuclear attack. Because many defense systems — such as the Distant Early Warning line of radars installed in the Arctic Circle — relied on telephone lines to relay signals back to military installations, such as the U.S. Air Force's SAGE installations, it was critical the network stayed online. Some relay sites also acted as ground entry points (GEPs) for military radio systems, such as the Echo-Fox network that communicated with Air Force One, or AUTOVON. Large hardened and underground sites often have large natural gas-powered turbine generators that can keep it running for lengthy periods, and featured accommodations for people who may be staying at the site. In case of a nuclear blast, these sites were constructed to withstand the blast and its fallout. The sites also had decontamination showers, fallout shelters and kitchens stocked with supplies just in case the worst-case scenario occurred.

All sites, regardless of how well it was built to withstand a blast, were made for resilience. After all, a single site could be handling thousands of telephone calls or several television broadcasts. The Bell System had many issues to contend with, such as the reliability and longevity of the vacuum tubes used in its equipment, other equipment failures, and external factors such as power failures or vandalism. With the massive research arm of Bell Telephone Laboratories, and Western Electric — Bell System's manufacturing arm — many issues were easily solved. Each facility had a backup generator, and all remote (unmanned) sites had alarm systems that alerted technicians at a local office of any issues. If a site did completely fail, the system was designed so that channels carrying calls could be diverted. Long Lines also had portable relay stations that could be set up if a site was down for lengthy periods, such as when the "American Republican Army" destroyed a Utah repeater site in 1961.

Terrestrial microwave relay, however, had become surpassed by fiber optics and satellites as the Cold War grew to a close. Following the Bell System's divestiture in 1984, parts of the Long Lines system slowly started going dark as the radios were "turned down" as fiber optics became more prevalent. In the 1990s, the boom of digital communications, such as the internet, started farther widespread adoption of fiber lines that had far greater capacity. Today, nearly all of the original Long Lines microwave relay routes have long been out of service since the 1990s or 2000s.

While the Long Lines system has been retired, AT&T kept some of the larger sites for use as switching centers or fiber hubs. However, a majority of the sites were sold off. In 1999, AT&T sold most of its towers to American Tower Corporation, who in turn leases out space to users such as cell carriers and land mobile repeater operators. (AT&T even leases some of the former Long Lines sites for its mobile cell service.) Other sites went to smaller tower companies, such as Subcarrier Communications, McCullough Comsites or "Sedalia Smiles". Over time, the towers have further changed hands — such as many of McCullough's former Long Lines sites now being used as repeater sites for the Missouri Statewide Interoperability Network used by public safety agencies in Missouri.

With the new use, however, comes erasing a part of the past. The Western Electric TD-2 microwave radios the sites originally used have mostly been long recycled, and the iconic KS-15676 horn-reflector antennas also removed and recycled to make space for new antennas. Some sites have been converted for other uses, and a few have been completely removed. The internet, however, allows for these sites — and memories of the Bell System altogether — to be remembered in the future.

Since 2018 I have documented several former Long Lines sites in the central Missouri region, with plans to visit and photograph more in Missouri along with neighboring states. In some cases, I have republished others' photos or information of area sites, with credit. Click here to read more about my personal connection to the AT&T Long Lines network.

Missouri sites

To implement a coast-to-coast telephone network, AT&T constructed microwave routes to carry telephone and/or television traffic across the United States and Canada. Relay sites, typically unmanned, were constructed every 25-40 miles to "amplify" the signal for the next station(s), or "hop(s.)" A site may only have hop, such as if it was a terminal site on a spur route (e.g. Jefferson City, a spur TV site with only one "hop" from Holts Summit), or two hops if it was only on one route (e.g. Hermann, with a east hop from Holts Summit and a west hop to Gray Summit). However, many sites were used on more than one route, with some sites having more than eight or 10 sites it could be talking to on four or five different routes.

Another key part of the AT&T Long Lines system, as with the rest of AT&T's telephony business, was the central office. A central office, or CO, was essentially the hub of that area's telephone system. (Most cities had one CO, while larger cities and metropolitan areas had several central offices spread throughout different regions or neighborhoods.) Central offices were not only used to house operators and the switching equipment, but were also used as microwave relay sites in the Long Lines system.

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More information

Please check back later, but I hope to have more information available for the following topics.

Links

External links to other websites about the Long Lines microwave network, the Bell System and other related telephony history links. All external links open in a new browser tab.

Contact me

If you have any questions, concerns — or notice incorrect information, broken links, etc. — please email me.

My photos posted here, along with the information, are published under the Creative Commons CC BY-NC-SA 4.0 license. You may share these photos for non-commercial purposes, and edit or build upon them for non-commercial purposes. However, any use outside of this website shall provide proper credit (Garrett Fuller, personal.garrettfuller.org) and share using the same CC BY-NC-SA 4.0 or equivalent license.

For photos taken by others and published or republished here, please refer to the text (usually before the photos) or contact me before sharing.

Last updated: Nov. 5, 2024.

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