The technology we use to communicate has a dramatic influence on how we connect, share information, and interact. Before the ubiquity of cell phones, AT&T’s Long Lines network was critical in enabling long-distance communication! It’s been more than forty years since the program was discontinued, but across Indiana, old Long Line relics tower over their surroundings.

My family took a lot of trips from Muncie to Fort Wayne when I was growing up. Seventy minutes was a long time for a kid in the car, but a pair of steel towers with strange fixtures near Warren and Markle punctuated the drive. The monoliths looked different than the radio and TV towers I was used to seeing, and they piqued my interest.

I moved to Elkhart in high school. Dad and I frequently passed concrete towers with similar components as we went through Angola, LaGrange, and Goshen. Later, I found another in Wauseon, Ohio. Today, I work within spitting range of another in Anderson. They were all once part of the Long Lines network. The towers are everywhere!

We take our iPhones or Androids for granted today, but the earliest telephone networks were local. Each subscriber had a dedicated line that connected to a central office called the local exchange. There, operators manually connected calls by plugging and unplugging wires.

Soon, it became necessary to interconnect local exchanges to enable long-distance calls. Companies began to extend their networks by stringing open-wire lines, and later coaxial cables, from city to city. Unfortunately, the practice was insecure and expensive. In the 1940s, AT&T’s Bell Labs sought to change things by using microwaves.

As far as I understand them, microwaves are a type of electromagnetic radiation that exist within a specific range of wavelengths. Microwaves are like radio waves, but they’re free from static and don’t follow the curvature of the earth¹. To harness them for telecommunications instead of costly cables, Bell had to find a way to gather them into beams and shoot them toward their destination.

Bell figured it out in 1947. That year, the lab inaugurated an experimental technology called TDX that successfully transmitted telephone and television signals between Boston and New York City. The arrangement worked by passing a baton of microwave signals though a series of line-of-sight towers thirty or forty miles apart².

An improvement to the TDX system called TD-2 was rolled out in 1950. The first installation linked Chicago and New York. The line went right through northern Indiana and Ohio³! The new technology allowed the system to carry more calls but required the use of horn antennas called KS-15676’s. Those are the unique fixtures I remember from my youth.

The earliest TD-2 towers were concrete to shield the horns and provide security, but later structures were steel. For more than thirty years, the system relayed microwave beams from central terminals like Muncie’s to repeater towers in a zig-zag fashion to avoid any overlaps.

All in all, AT&T’s Long Lines network was revolutionary in expanding long-distance communications, improving call quality, and building a backbone for national defense. The influence of the Long Lines network can’t be overstated!

Unfortunately, the network’s utility ended once geostationary satellites and improvements in fiberoptic technology came to market. AT&T shut the system down after competitors introduced digital networks. The company’s Bell Telephone System was broken up in 1982, and Indiana’s portion of the monopoly eventually became part of Ameritech.

Ameritech removed Muncie’s idled microwave antennas from the city’s central terminal in 1994⁷. Most of the original Long Line towers were sold in 1999, but many remain standing despite the removal of their horns. I’m sad to say that neither of the towers I remember from trips up I-69 retain theirs.

Despite that, tracking down and researching the towers of AT&T’s Long Line network in Indiana will probably become my next big statewide project. Many outside the midwest have been documented in one way or another, but I haven’t found much information about Indiana’s installations. I hope to rectify that!

Today is my 33rd birthday. The coming weekend will mark the sixth year my mom’s marked it with a long history drive as my present, and I plan to use the occasion to document the old Long Line towers from Anderson to Angola and back. I’ve only been to a handful of sites so far, but I can’t wait to help shed some light on Indiana’s complex network of wires and microwave towers that once revolutionized communication.

Sources Cited
1 Seven towers on seven hilltops (1947). Bell Telephone System. Long Lines Department [New York]. Advertisement.
2 The Latest Word in Communications (1947). Bell Telephone System. Long Lines Department [New York]. Pamphlet.
3 Disckieson, A.C. (1967, October). The TD2 Story: From Research to Field Trial. The Bell Laboratories Record [New York]. p. 283.
4 Randolph County Office of Information & GIS Services. (2022). Parcel ID: 68-13-30-400-018.000-016. Randolph County, Indiana Assessor. map, Winchester, IN.
5 FCC Registered Cell Phone and Antenna Towers in Lynn, Indiana (n.d.). City-Data.com. Web. Retrieved November 5, 2023.
6 Kohlstedt, K. (2017, October 20). Vintage Skynet: AT&T’s Abandoned “Long Lines” Microwave Tower Network. 99% Invisible. Web. Retrieved November 5, 2023.
7 Penticuff, D. (1997, June 15). Tower talk. The Muncie Star Press. p. 45.