Using silicone to plug waterlogged cable
Longtime Verizon Communications District Manager Rick Niblick knew a serious problem when he saw it: Water had permeated an aircore telephone cable that housed 600 copper pairs, serving businesses in a major shopping mall in New Philadelphia, Ohio.
Verizon business customers in the mall were wrestling with static on voice lines. Internet connections were being cut off and credit-authorization calls were being interrupted during sales transactions. Complaints festered.
Company engineers told Niblick it would cost at least $29,000 to repair or replace 3,000 feet of affected cable. But that wasnt the worst scenario. Niblicks crews would have to dig up the more than half-mile of line in a single night while the mall was closed or shut the retail businesses dependent on the phone lines.
"I just didnt think there was any way we could do it overnight," he says.
Then Niblick stumbled across a new technique that has recently been adapted to telecommunications infrastructure problems from an unlikely source silicone implants, like those used in cosmetic surgery.
"It was a new wrinkle in an old process," he says. "And it worked for us incredibly well."
Using silicone at the consistency of water, Utilx vacuums air from the cable on one end while pumping the material into the cable from the other. It pushes the water out as it works. The Seattle utility renovation company had been using a similar technology to fill waterlogged electric cable for nearly 15 years. An adaptation of a process perfected at Dow Corning allows Utilx to restore aircore telephone cable to its original specifications or better.
As the silicone oozes through the cable, it fills and patches holes and coats the copper wires, making them waterproof. A hardener turns the liquid into a gel that is the consistency of Jell-O.
"We filled the cable to the mall without ever interrupting service," Niblick says. "And it cost us $4,800 instead of $29,000. Now Im pushing for us to do this proactively, to fill aircore cable before it becomes affected by water."
Industry experts estimate that more than 400,000 miles of aging aircore cable is in the ground in the U.S., most of it installed more than a decade ago and much of it increasingly problematic for telephone companies.
The most serious outbreak of service interruptions for telephone customers occurred over the past year in the five-state Great Lakes region served by Ameritech, which merged with SBC Communications last year.
SBC/Ameritech blamed the problems on a number of things, including wet weather that affected underground cables. But others, including some state regulators, faulted Ameritech for failing to maintain its infrastructure or replace water-damaged cable during the years before its merger with SBC.
Jerry Solomon, Utilxs marketing development manager, says Utilx has had good response from the regional Bell companies and smaller local exchange carriers though SBC is not using the technology in its troubled Ameritech region.
Erasing a Bad Rap
Ron Kain, a sales manager at Utilx in Texas, says some carriers are resistant to the new technology because they had trouble with an earlier process that pumped a petroleum-based product called Revite into aircore cable. He says the petroleum eventually caused deterioration of the sheath surrounding the copper pairs, creating more problems than it solved.
Silicone, Kain says, not only pushes water out of the cable, but seals the cable to prevent recurring problems.
"This process admittedly isnt for every situation," Solomon says. "There are some cases where it may be cheaper to replace the cable. Especially in cities where you have the costs of closing streets, digging up entire city blocks, replacing concrete and asphalt, this is much cheaper, much quicker and easier."
Shannon Ostlie, a district supervisor at 3 Rivers Telephone Cooperative in Fairfield, Mont., has put the silicone implants to work in rural areas.
"We had one cable that ran through agricultural land, and wed had a lot of problems with water. It had been spliced, and we had tried to repair it several times without success. We were looking at $10,000 to replace it.
"They filled about 4,000 feet for us, for 75 cents a foot, and we havent had any problems with it since," Ostlie says. "We had a customer at the end of the line who kept calling because he would get knocked off the Internet. Afterward, he says his hookup never worked better."
Niblick says the buildup of static in wet cables not only causes Internet disconnects but can slow Web access to a crawl.
"When you see reports that say Internet customers are suddenly running at half their normal speed, one of the first things you suspect is wet cable," Niblick says.