Tinker retires phone system dating back over 40 years

  • Published
  • By Clayton Cummins

A decommissioning ceremony was held to officially retire the legacy phone system at Tinker Air Force Base.

The ceremony was held Oct. 4, 2024, where Col. Abby Ruscetta, Tinker Installation and 72nd Air Base Wing commander, pulled the fuses on the Class 5 Electronic Switching System, better known as 5ESS, officially sunsetting the old system.

The 5ESS is a digital phone system that was developed by AT&T and Lucent Technologies. It was designed to replace older analog systems. 5ESS offered improved call routing and handling, as well as support for various telecommunications services, including both circuit-switched and packet-switched communications.

During the 1984 fire in building 3001, the telephone switch proved to be critical to base operations. Switch technicians frantically sandbagged the dial central office to stop the thousands of gallons of water used for extinguishing the fire.

“It needed to get it replaced,” said Lawerence Hagler, chief of the Cable and Antenna Systems Branch for the 72nd Air Base Wing. “We were keeping it alive by going on eBay to buy parts because they stopped producing them almost 10 years ago, we couldn’t find them anywhere. It was the gem of the group when they bought it, it has plenty of capacity, the problem was sustainment.”

Equipment for a voice over internet protocol, known as VoIP, system was purchased in 2022 to replace the 5ESS system. It is the largest voice project at Tinker conducted in more than 40 years.

“The VOIP only takes up two racks of equipment where the 5ESS equipment takes up an entire room,” said Hagler. “Our new system has way more capability than the old switch.”

James Powell and Kevin Norman, IT specialists at Tinker, both have over a decade of experience working on base. In that time, the co-workers say they have developed fond memories of the 5ESS phone system including a time in the early 2010s when a water line burst in building 416 during an OU-Texas football game.

“We turned off the power quickly,” said Powell. “One of the managers we worked for bought a bunch of blow dryers so we could dry the thing out over the weekend. We got enough spare packs back into it to get it back into service.”

“We figured It would have to be a total replacement, but it lived on for at least another 10 years or so,” said Norman. “We were very surprised.”

The last users of the 5ESS system at Tinker transitioned to the VOIP system in September 2023.

After the system was decommissioned, it will be taken apart and scrapped for parts.