When O&G Industries won the bid for the I-91 Charter Oak Bridge Project which included upgrading a six-mile section of Interstate 91 just outside of Hartford, Connecticut, they used the opportunity to grow their already impressive list of construction capabilities. Not satisfied relying upon traditional paving methods for the $213 million project, the company employed a state-of-the-art road resurfacing solution called SmoothRide from Topcon (Livermore, Calif.) which uses high-density laser scanning of the road surface as a basis for the design, milling and paving facets of the job. By project’s end, the solution had both improved the company’s overall workflow and produced superior paving results which, predictably, had them saying a whole lot more than just “Oh!” and “Gee!”
Double Teaming It
The Charter Oak project, which O&G performed for Connecticut Department of Transportation (CTDOT) as part of a joint venture with Barletta Heavy Division, is a complex undertaking. Actually a combination of two projects, Charter Oak involved the relocation of an exit; the widening of several main routes; and I-91-based resurfacing, bridge and safety improvements. It is on this latter portion of the job that O&G chose to expand its paving efforts, according to Josh Williams, P.E., the company’s paving superintendent on the project.
“One of the primary considerations in the resurfacing facet of the job was road re-profiling,” he said. “CTDOT’s new design called for an elevation change in the highway’s crown, a fairly major undertaking. We are fortunate that our company’s upper management is always looking for ways to improve the various processes that make up the job. Construction often has a tendency to lag a bit in innovation; thankfully, we seem to be ahead of the curve in a lot of regards — turning to the SmoothRide solution is a great example of it.”
Williams added that, prior to reaching out to the Hartford branch of the Topcon Solutions Store, O&G looked into multiple avenues — and manufacturers — to get the Charter Oak job done and chose the Topcon SmoothRide system. “We liked the fact that we could scan the road, confirm where the existing surface was and then, in the paver, overlay CTDOT’s plan, and literally pave the difference. It was a big departure for us but we had a level of confidence that it was the right choice.”
“One of the primary considerations in the resurfacing facet of the job was road re-profiling.”
– Josh Williams, P.E., the company’s paving superintendent on the project
Hitting the Road
By way of background, the SmoothRide Resurfacing System begins with a precision assessment of the existing road surface using a vehicle-based RD-M1 scanner — in O&G’s case, mounted on one of their fleet pickups. Then, using Topcon’s MAGNET Collage software, a point cloud is created from the scanned data and used to create a design surface which is further refined to meet CTDOT’s specifications using the resurfacing module of MAGNET Office Site. The design comes to life with the RD-MC system which controls the paving and milling processes using both a sonic tracker for tight vertical control and GNSS to deliver positional guidance.
“Most of this job was already low but we used the RD-MC on our milling machine for touch-up work on some areas of 91 southbound and it worked great,” said Williams. “However, every other facet of the job has benefited — from eliminating the time-intensive, risky process of gathering cross-section measurements, to the 35,000 tons of variable-depth paving. I personally handled that first point, the scanning, and can attest to how fast and safe it made that process.”
Williams said they scanned the entire seven miles of road — 3.5 miles in each direction — in a fraction of what it would have taken doing traditional cross-sections. More importantly, he added, it took people out of harm’s way and saved on survey costs.
“It was a real departure for us,” he said. “Instead of shooting the whole road — every lane break — with GPS, we were able to simply drive down the road in the middle of the day, in live traffic. That made a huge difference in terms of productivity. Mind you, the system is not inexpensive. But, when you factor in the savings in both time and survey costs, then couple that with the added safety, we will get a nice, quick return on our investment.”
In addition to an overall aggressive 30-month schedule for the Charter Oak project, O&G’s teams faced some logistical challenges on a daily basis as well. “We have to have the pylons out by 9:00 each night and then, after paving through the night, we have to be off the highway by 5:00 a.m.,” said Williams. “So that eight-hour shift is really closer to seven.”
“Most of this job was already low but we used the RD-MC on our milling machine for touch-up work on some areas of 91 southbound and it worked great.”
– Josh Williams, P.E., the company’s paving superintendent on the project
Smooth Transition, Too
While moving to the new technology could have been a disruptive experience, O&G’s team said that a combination of the system’s ease of use and the support they received helped alleviate most all of those concerns.
“Getting into the new technology was actually pretty easy,” said Paul Kuna, the company’s quality control engineer. “Even though I had a little bit of surveying experience from work with a previous company, the system itself was very intuitive and easy to understand. So, even without that prior experience, I would have been just fine.”
Williams added that, simple though the addition of SmoothRide has been, they were helped tremendously by the support they received from their area Topcon Solutions Store (TSS) in Hartford. “Topcon has been outstanding,” he said. “They flew a team out here from California to be onsite with us for several shifts the first year we had the system and then came back out again this year to provide something of a refresher for us. We also spoke regularly with people from All Roads Construction in Canada, a company that has been a SmoothRide user for a couple years now, to tap their expertise. Locally, Dennis Kessler and Rich Gaudio from TSS have been excellent, helping us with whatever we might need and being ready to answer any questions we might have — day or night. There’s no substitute for that kind of service.”
No Jumps Needed
As mentioned, O&G did look at alternative systems to upgrade their paving efforts. While some were intriguing and seemingly worthy of consideration, upon getting into the finer workings of those solutions, said Williams, their shortcomings became evident.
“The other millimeter system we really zeroed in on, while looking like it could provide the results we need, had a major drawback,” said Williams. “The technology relied upon total stations, which meant we would have needed to have a station set up and ‘surveyed in’ every 500 ft., then continue jumping those units all night. That was not what we were looking for at all.”
He added that, by comparison, the Topcon solution needs only one base receiver setup, and one file to control the job — a much simpler approach.
“This works off GPS positioning, so we simply set up the base and it talks to the paver,” he said. “Both the base and the paver — which is equipped with sonic tracker sensors for full 3D automation — are working off the same model and as the paver moves, the model it tells it what the thickness is. And, once we dial in the paver, all we are doing is spot checking. We are not constantly turning the screw trying to chase a number in front of us — the paver does all that for us. We’ve altered some things for rideability, mostly adjusting the gain of the machine to allow it to react more quickly to the model. But it’s been great for us and puts in cross-slopes particularly well, easily as good as what the best paving crew could do — and does so more efficiently.”
Smoothing Forward
Williams is quick to note that they have literally only scratched the surface of what the SmoothRide solution can do for them. Quantity verification, for one, is an area that holds interest to O&G.
“I know that we can use the solution to determine how many tons of material are in a stretch, simply by comparing the two surfaces,” he said. “Though that could be a real benefit, we didn’t elect to do it at Charter Oaks , largely because of time constraints — once we complete the scan we need to get it processed quickly and pave with it later that day. On a job that is not as fast-paced, however, we will be able to so much more with it. And while the system can also be utilized to streamline the milling part of the job, as mentioned, we didn’t do so at Charter Oak because the surface was already so low.”
While O&G generally doesn’t self-design its road projects — the Charter Oak job was designed by the Rochester, N.Y. branch of GDB Geospatial — Williams knows that SmoothRide’s strengths are such that doing so is feasible.
“I understand that it would be possible to scan a road, and, based on design parameters, have the software tell us the ideal profile of cross-slope of the road, as well as quantities for milling, shimming and paving,” he said. “If we were looking to redesign a road, we could easily do so using the RD-M1 and the accompanying software. While we have no plans for road design at this point, that’s still a very powerful tool to have handy.”
