Control Is Key
Whether losing it or using it
Located in the Town of Tonawanda, NY, just north of downtown Buffalo, the I-190/I-290 interchange is one of the busiest in the area, handing better than 70,000 vehicles every day and serving as a vital link for traffic headed to and from Niagara Falls. Built in 1962, the pair of curved, twin elevated spans have been showing signs of wear for years and have been the cause of countless overturned vehicle accidents. Based largely on those facts, the New York State Department of Transportation (NYSDOT) opted in 2009 to budget for total bridge replacement rather than just repair. For Oakgrove Construction, the firm awarded the $16 million project, it was a perfect fit for their core strengths and an even better opportunity to showcase the company’s newly acquired Topcon GPS-based machine control capability. Today, better than two-thirds of the way through the project, the Buffalo area is close to an era of improved highway safety, and Oakgrove’s machine control has proven an invaluable addition to the business.
A Mess by Any Other Name
While not as complex as, say, Dallas’s famed “Mixmaster” or the Twin Cities’ “Spaghetti Junction,” the I-190/I-290 interchange has been problematic for Buffalo area drivers almost since it was built. In several spots, cars exiting one highway have to merge through traffic attempting to enter as it exits the other. Doing so generally forces drivers to speed up. And therein lies the big problem, according to Mike McLaughlin, Oakgrove’s vice president of operations.
“Things have changed quite a bit since these structures were built,” he says. “For example, today’s commercial vehicles are larger and faster than they were back then. At the same time, speed limits are higher now. Couple that with a bit of overconfident driving, and you have an overturned tractor trailer—which has been the case many times at this interchange. Increasing the cross slopes on the structures from their current 6% up to 8% should reduce that type of accident dramatically.”
|Topcon’s rover makes it possible for project managers to check out work in progress.
Oakgrove started the project in the fall of 2009. The total package includes reconstruction of the two 400-foot, two-lane overpasses as well as new on-ramps and off-ramps to both highways. Because the interchange is such a critical component of daily travel, it was decided that the pair of existing structures would remain fully operational until the two new overpasses were built. At that time, traffic will be switched to the new overpasses and the old ones will be demolished.
Taking Control of the Project
In business for more than half a century—all of that time as a highway/heavy contractor with a specialty in road and bridge rehab—Oakgrove Construction is, obviously, very good at what it does. A major part of the reason for its longevity and its success is an unwillingness to settle for the status quo. Instead, the company is always seeking new ways to improve the operation, a commitment that led it to explore GPS about three years ago.
“We make a concerted effort to keep aware of changes within our industry, whether it’s in equipment, procedures, techniques, whatever—you simply have to today,” says McLaughlin. “We saw the benefits that GPS could bring to Oakgrove, did a good deal of research into what was out there, and felt that Topcon was the way we wanted to go.”
It’s no secret that the construction business revolves around companies essentially monitoring what others like it are doing, and that, too, played a role in Oakgrove’s push to add GPS. “We saw that our competition was going that route and having success with it; knowing that helped steer us in that direction. So, working through Admar Supply, the regional Topcon dealer, we purchased our first system, a Topcon GR-3 receiver and rover.”
While the factors mentioned above also played a part in Oakgrove making a push to machine control, it was the nature of the Buffalo expressway project itself that really sealed the deal, so to speak.
“Because of the bridge reconstruction facet of the job, we knew we would be moving better than 150,000 cubic yards of soil, almost half of which would be going into embankment, so it seemed like the perfect time to give it a try,” says McLaughlin. “We bought one Topcon 3D-MC system to start with, and then, based on the success we were having with it, bought a second system later the same year.”
|The 3D-MC system from Topcon gives the operator the information he needs to complete the task stakelessly.
Realizing the Savings
McLaughlin says one of the main benefits machine control is providing on the 190/290 project is an ability to replace a grade foreman. “It’s a savings for us to be able to send an operator out with his machine without having to send a ground man out to control him.”
Oakgrove relied upon a pair of dozers—a Cat D5 and a Cat D6—and, when one machine had to be moved to another project, rented an additional unit, also with Topcon machine control, from Admar.
“We became believers in this technology very quickly,” says Larry Zak, Oakgrove’s project superintendent. “Since implementing the systems, we have been saving time with survey, with staking, with checking. It’s really benefiting us across the board.”
For Cort Baker, a partner in the company and one of Oakgrove’s senior engineers on the project, it is the overall complexity of the interchange that has presented the greatest challenge, a challenge that is being met by machine control. “This job is an interchange of two major highways, both on curves, both heavily super-elevated. It is three-dimensional in every respect: there are circular curves, there are spiral curves, it has very complex geometries. Staking out a job like this would have been a nightmare, so being able to have that in a model and create it using machines was a real plus.”
One area in which Oakgrove had not anticipated making inroads, was with onsite inspectors who, on a regular basis, need to verify that specs are being maintained. Not long after bringing in the first dozer with the Topcon 3D-MC system, however, the inspectors saw just how accurate Oakgrove was in its cuts and grades, and they became converts as well. “When the machine said it was good, they were satisfied,” says Zak. “Granted, it also made their lives easier, but the bottom line is they knew we were right on and, as a result, they had no concerns.”
Ramping Up Production
When Zak speaks about needing a bit of convincing, he does so from experience, having been a skeptic himself from the outset. “But within a day I was sold, just on the ease of use, and I knew that it was all Admar had promised it would be. Now, as long as I have a rover onsite, I have peace of mind that the job will be done right. If we are excavating a 1,500-cubic-meter hole for a bridge abutment, I can just put a decent operator out there and not have to worry again. It’s that solid.”
He adds that the equipment required very little in the way of a learning curve and has been extremely reliable in its performance. “We haven’t had any major problems to speak of,” he says, “and the few glitches we’ve had along the way have been quickly handled by Admar. They really back what they sell.”
Because of the reconstruction of the twin-elevated structures, the project calls for complete relocation of the ramp from westbound I-290 to both northbound and southbound I-190. Another ramp from the southbound 190 to the eastbound 290 is also being completely rebuilt. “Those were areas that, in the past, would have needed to be extensively staked, cut, graded, checked, restaked, and so on,” says Zak. “With the Topcon system, everything is in the dozer’s file and it’s a one-shot deal. That has really streamlined the ramp work for us.”
As a result of the role GPS is playing in the interchange project, Oakgrove has been able to do the entire job using only one surveyor. And, says Zak, that surveyor’s job has been made much easier by having the Topcon gear onsite. “We have the base set up and our surveyor does all his layout with one rover. However, I have a second one as well and that frees him up further since we don’t have to continually go to him with issues; we can do so much on our own.”
Oakgrove’s completion date for the 190/290 project is set for the end of 2011, but the company expects to be out by the fall of this year.
Author's Bio: Industry writer Larry Trojak is based in Coon Rapids, MI.