Install more than 75,000 ft. of high-density polyethylene main line conduit to connect multiple homes and businesses to broadband services
Grand River Mutual Telephone Corporation
MasTec North America
Jackson Creek Enterprises
The existing Bell System infrastructure serving several small rural communities along the Iowa/Missouri border was an aging system of spliced lines and slow connections. So, Grand River Mutual Telephone Corporation, located in Princeton, Mo., initiated an upgrade. The local service provider applied for and was awarded a Last-Mile Award, made possible by the U.S. Department of Agriculture Rural Utilities Service, to install new lines. More than $14 million of the $20-plus-million project was provided through the American Recovery and Reinvestment Act of 2009.
Grand River Mutual, along with general contractor MasTec North America, based in Shevlin, Minn., selected installation contractor Jackson Creek Enterprises, headquartered in nearby Allerton, Iowa, to install the new network. Spanning more than 150 miles, the Grand River Mutual Fiber-to-the-Home Broadband Deployment Project - Service Area 5 will provide broadband service to the towns of Corydon, Millerton, Allerton and Lineville, Iowa, and Powersville, Mo., including 1,997 homes and 339 local businesses.
David Wampler, found and president of Jackson Creek Enterprises, selected the Vermeer D7x11 Navigator Series II horizontal directional drill for the Grand River Mutual job, which includes installing more than 75,000 feet of 1.25- to 2-inch high-density polyethylene main line conduit, along with connections to each home and business.
“All of the main line consists of conduit that we’re installing using HDD,” Wampler says. “I bought a Vermeer LM42 plow to bury the individual drops to connect the homes and businesses. The majority of the conduit is 1.25 inch, but there are places where there is 2-inch pipe within the network where we’ve bundled multiples. At those locations we pulled back two or three, sometimes even four conduits. We also set all of the pedestals. All lines terminate into a pedestal at some point.”
The fertile, rich topsoil with intermittent pockets of sticky clay, prevalent in this region is also an HDD operator’s delight; hence, ground conditions were of minimal concern. The biggest challenge for Wampler’s crew of trenchless installation specialists was locating the several utility lines beneath the surface within the city limits of the many communities connected by the new fiber network. To minimize disturbance and potential damage to existing underground lines required extensive potholing and locating efforts.
“We have great city crews here that have done a fabulous job of marking water and sewer lines,” Wampler said. “We won’t cross anything unless we have first potholed the location to confirm visually where all these different utilities are located. Most of the time, our potholing crew could keep a day ahead of the drill; but with minimal ground condition challenges, we’ve been able to document impressive production rates.”
Wampler’s crews were able to complete individual bores ranging in length from 700 to 800 feet on average while individual drops connecting businesses and homes fell within the 20- to 40-foot range.
The main line conduit was installed at a depth of 36 inches or greater, while connections to individual homes and businesses were installed with the Vermeer LM42 vibratory plow at an average depth of 18 inches. Scant amounts of a polymer/bentonite drilling fluid mixture were introduced into the bore path periodically - primarily to help keep electronics cool - since maintaining bore integrity wasn’t as much of a concern drilling in the heavy clay soil composition as it would have been if boring through other conditions that are less stable. A standard 6-inch fluted back reamer was used to bore those areas where multiple conduits were pulled back simultaneously.