Clarkstown NY is a town of 84,000, across the Hudson River from Brooklyn and about 30 miles north. It’s fair to call the area affluent, but until recently you wouldn’t know it from the town’s 300 miles of roadway. “Up until 2018 we didn’t do much in the way of annual maintenance other than mill-and-pave, and raising manholes to grade with cast iron rings,” says Street Construction Inspector Jeffrey Lawrence. “This took a toll on roads, and we realized that we needed a more sophisticated approach if we wanted more mileage for our investment.” A central feature of the new approach was the use of ultra-thin, ultra-durable wear layers of advanced paving material, typically applied in one-inch thicknesses. “It’s a better quality surface and a better looking surface, in every important way,” says Lawrence.
But ultra-thin layers do present a challenge when it comes to raising manholes. The cast iron risers that Clarkstown was using are simply not available in thin sizes, which means that Lawrence was faced with the possibility that his durable and immaculate new roadway surfaces would be marred by shallow potholes at every manhole. And in a region with lots of annual freeze/thaw cycles, and plenty of snow plowing and road salting, that just wouldn’t do. So, “I started looking around,” he says. And discovered the American Highway Products Pivoted Turnbuckle Manhole Riser.
The AHP adjustable risers are sturdy, lightweight rings of flexible U.S. steel, joined with turnbuckles that make it easy (with no training required) to expand or contract the riser using a screwdriver as a lever to apply 5,600 lb. of pressure evenly around the entire circumference of the riser. This enormous force easily and permanently fits the riser snugly to the existing frame, at the exact height needed to match new road grades.
Importantly for Lawrence, they are available in very thin heights, and customizable in 1/4-inch increments. “In four years, we’ve purchased over 700 American Highway Products risers, mostly in 3/4-inch and 1-inch riser heights,” he says. “They’re high-quality, reliable, affordable, and I like that they’re made in the USA.”
And quick and easy to install permanently. “I do most of the installs myself, just a one-man crew. An install literally takes just a minute and a half—I clean off the original rim, pop in the riser, and tighten it in,” Lawrence says. “Honestly, it’s kind of thrilling.” Especially compared to a manual adjustment of the casting, which can take a two-man crew hours to complete.
“And I’ve never had one come out! The American Highway Products riser is a great product, with great results, and makes for a great road!”
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.