New Philadelphia makes adjustable risers standard for road projects
By Angus Stocking
For many, New Philadelphia, Ohio, is a slice of midwestern Americana you don’t often find anymore. Its Victorian houses, quaint-yet-bustling downtown area and tree-lined streets are a Rockwellian throwback to simpler times.
Unless, of course, it’s your job to keep those streets up to grade.
That’s where Brian Myers comes in. As the town’s Wastewater Superintendent, the roads Myers helps manage aren’t just picturesque — they’re historic: the town began as a Moravian Church mission to the Delaware Indians in 1772; was laid out in 1804 in the grid style pioneered by its eventual namesake, Philadelphia; and incorporated in 1833.
As one can imagine, there’s nothing simple about keeping 250-year-old road grids operable. Thanks to American Highway Products’ pivoted turnbuckle adjustable risers, however, Myers said he’s been able to at least make the process easier.
Old problem, new fix
Like most sewer network managers, it’s Myers’ responsibility to keep the city’s manholes at grade after roads are repaved, or when manholes fail and need to be repaired. Traditionally that meant fully excavating the manhole chimney, installing a new casting and adding concrete casting rings as needed to bring the manholes to grade.
“Then we’d usually have to do the hot patching the next day,” Myers said. “It was a lot.”
Occasionally, though, Myers and his teams would use an AHP pivoted turnbuckle riser, and he said the difference in manpower between the two solutions was easy to see – the AHP solution was simply more efficient.
“Putting in a brand-new casting and new concrete riser rings is certainly a durable and high-quality fix,” said Myers, “but excavating, and then setting and adjusting the new casting and rings could easily take all day.
Myers’ views on the high labor costs associated with traditional manhole raising are backed up by data from municipalities across the nation. A study in Shoreline, Wash., analyzed three years of maintenance records and determined that raising manholes carried an average cost of $500 per manhole for labor and materials. In this case, the district was covering the manhole at time of paving, then jackhammering new pavement at a later date before digging out the manhole frame and raising with precast grade rings. In a similar scenario, the southern California city of Ontario found that labor costs were $360 per manhole when using precast grade rings. Considering that many municipalities must budget for dozens, or even hundreds, of manholes, the costs can quickly become substantial.
Even worse, this traditional process may cause more harm than good. Hot patching, or the use of hot mix asphalt, to fill in excavated pavement has a proven negative affect on quality and roadway durability. This is mainly due to the inevitably uneven joint between smooth, newly installed pavement and the rough, lower-quality hot mix patch.
In his 2004 report, “A Look at the Effects of Manholes on Street Condition,” Steve Rinne surveyed 480 manholes in Kansas City. Of those, 30 percent were found to be substantially above or below grade. The pavement around the observed manholes was also assessed. Around the uneven manholes, 35 percent of the pavement was rated as “bad,” as opposed to just 11 percent of the pavement surrounding at-grade manholes. These numbers certainly suggest that uneven manholes contribute to pavement wear.
To put it another way, “smooth pavement lasts longer,” according to the National Asphalt Paving Association’s report, “Thin Asphalt Overlay for Pavement Preservation.”
Better for New Philadelphia
In contrast to the standard manhole raising technique, AHP adjustable risers can take as little as ten minutes to install. Even better, there’s no excavation or hot patching required. The secret is the pivoted turnbuckle; American Highway Products manhole risers are open, flexible rings made of high-quality, galvanized steel that can be expanded or contracted easily with a screwdriver. They’re available in precisely sized diameter and thickness increments, which allows crews to bring manholes to exact new paving surface grades.
“We order them as needed, in the sizes we need, and they always get to us in a timely manner,” says Myers. “It’s a great product, and they’re a great company to work with—we’ve never had any complaints.”
The whole installation process is simple: just place the new riser where you need it and crank the turnbuckle until it’s seated securely and tightly. Instead of one or two days to raise a single manhole to grade, the AHP adjustable risers make it feasible to raise dozens of manholes in a day, all while avoiding extensive traffic closures. In 2019, New Philadelphia installed 35 of the pivoted turnbuckle risers, including 25 on a single resurfacing project.
In addition to quality benefits and labor savings, installing adjustable manhole risers offer an additional advantage over the more-traditional manhole raising method: safety. When manholes are raised to new grade quickly during paving operations, exposure to traffic and construction equipment is minimal. That’s not to mention the sizable weight of the manhole raising equipment that’s often used; heavy, precast grade rings can cause lifting, crushing, or pinching injuries, and they can happen during delivery, storage, loading and construction. These risks simply do not exist when using AHP’s galvanized steel rings, which are considerably lighter yet still sturdy enough for the job.
Altogether, AHP’s manhole risers have provided an easy solution for a common problem and, in turn, have helped make Myers job just a bit easier.
“I like them and think they’re a better solution,” said Myers, “so now its adjustable risers that are our standard practice.”
Angus Stocking is a former licensed land surveyor who has been writing about infrastructure since 2002. American Highway Products can be reached at 1-888-272-2397 or by email at email@example.com