Art Reel, street superintendent St. Louis, Mo., is responsible for more than a million square yards of pavement. His division used to pave over manholes, leaving the water and sewer departments to dig them up if they wanted them back in service.
Their crews, however, sometimes cut in around the lid, leaving a pothole. The labor-intensive alternative for the Asphalt Paving and Maintenance Division was to jackhammer, then raise the frame using three-section risers.
“We had to seat all three segments just right and adjust them individually or they wouldn’t seal,” says Reel. “It was a real pain.” In 2001, he saw a demonstration of a manhole protector ring and riser that saved his division time and the city money.
Quick and powerful
Made by American Highway Products in Bolivar, Ohio, the steel manhole ring and riser eliminate jackhammers, excavation, bricklaying, and new cement when bringing manhole covers to grade after paving. The cover fits snugly into the new riser, preventing inflow and infiltration.
The custom-made risers come in five sizes, but even that doesn’t guarantee a snug fit, as existing frames can wear unevenly or be out of round. Installers therefore use an expanding and contracting turnbuckle that pivots at both ends to ensure freedom of motion through-out the 1 3/8-inch adjustment. The pivoting motion provides a plus or minus 1/2-inch diameter variation.
Using a Phillips head screwdriver — the only tool needed — as a lever, installers rotate the turnbuckle until the riser engages the full circumference of the hole.
New game plan
After testing some risers, Reel instituted a policy to install them as paving is done to keep manholes in service. “The commissioner and I worked out a deal with the sewer and water divisions to do this work on their behalf, and they reimburse us,” says Reel.
Manhole diameters are fairly constant, enabling Reel to stock several hundred 1- to 4-inch risers (2 inches is the most common). One city employee does nothing but install them, usually one in about 10 minutes. “Installation is pretty self-explanatory,” says Reel. “The risers are real sturdy, too. We haven’t had a single problem since we began using them seven years ago, and we install 2,000 annually.”
The Street Division is using the risers to systematically return paved-over manholes to service and bring low manholes to grade. “Citizens call in about potholes, but not everything is a pothole,” Reel explains. “Our patch guy carries risers now, and sometimes that’s all it takes.”
