As the second-largest (and fastest growing) city in Michigan with a population of more than 200,000, Grand Rapids is a progressive jewel of the Midwest, with an emphasis on creative innovation that extends all the way through city management to seemingly mundane details of roadway maintenance, including the raising of manholes to grade after milling and paving operations.
“We repave a lot of roadway annually, and raise more than 500 manholes most years,” explained Managing Director (Public Services Group) James Hurt. “It’s an important detail to get right, because if lids end up below grade they collect water and ice and become potholes, and if they’re just a little too high they catch vehicle tires and snowplow blades and cause serious problems.”
Since 2014, the Grand Rapids Street Maintenance Department has used the American Highway Products (AHP) Pivoted Turnbuckle Manhole Riser to securely raise manhole lids to new grade after paving operations. They are sturdy, lightweight, precisely-sized rims of galvanized U.S. steel—made in Bolivar, Ohio—that are made adjustable by a nifty (and patented) “pivoted turnbuckle” that will expand or contract the riser as needed to match original rim diameters. In practice, installation is as simple and fast as placing the adjustable riser in the original rim and tightening it, using a screwdriver or similar tool as a lever, thus effectively applying thousands of pounds of force along the entire riser-to-rim circumference, seating the riser tightly and permanently.
“We use a two-man crew and a truck, and put in the risers just before new lifts,” said Public Works Supervisor Jason Carter. “The pavement seals up tightly against the AHP riser, giving us a seamless new roadway and a very durable manhole—in fact, when correctly installed, we have never had a riser fail.”
Before adopting the AHP adjustable riser in 2014, the public works department used to raise manholes the conventional way, excavating around the chimney as needed and installing new concrete rings. According to Hurt, the process was slow, a little unsafe, came with sustainability costs, and was expensive. “We estimated $500 or more per raised manhole,” he said.
Grand Rapids now installs more than 500 American Highway Products risers annually, saving at least tens of thousands of dollars, improving sustainability, and exposing crews to less risk—all with a better quality solution. “We are 110% behind American Highway Products and their products,” said Hurt. “We expect to keep working with them for a long time.”
Editor's Note: Scranton Gillette Communications and the SGC Infrastructure Group are not liable for the accuracy, efficacy and validity of the claims made in this piece. The views expressed in this content do not reflect the position of the Roads & Bridges' Editorial Team.