When it comes to surveying road construction sites, using traditional methods can be slow and dangerous. That’s why an increasing number of companies are turning to UAVs, such as fixed-wing drones, to cover larger areas with greater efficiency and safety. GRAHAM Construction, an organisation that delivers building and civil engineering projects for both public and private sector clients, knows just how beneficial the technology can be.
In 2016, GRAHAM Construction was jointly awarded the contract to build Northern Ireland’s new £130 million ($175 million) A6 dual carriageway. The three-year project would task the company with helping to construct 14 kilometers (nine miles) of new roads.
While GRAHAM Construction had experience with similar big construction projects before, the company’s previous methods for regular cut and fill volume calculations relied primarily on terrestrial surveying instruments, which proved expensive and posed several safety concerns.
“Previously, our weekly or monthly measurements would be carried out by two or three staff using total station and GPS instruments,” explained Nick Kelly, senior land surveyor at GRAHAM Construction. “Then you would have all the data processing and volume calculation work after that, it was all very time-consuming.”
Time wasn’t the only obstacle the firm wanted to overcome. Kelly and his team needed a way to improve the safety of its quarry surveys, too. “Our surveyors also work our on-site quarries, where you have sheer rock cliffs and massive boulders, making these areas potentially very dangerous to survey.”
To complete the new project successfully, Kelly and his team needed a way to optimise the efficiency of the project and improve the safety of its quarry surveys, so he turned to the KOREC Group, the company’s primary supplier of geospatial equipment.
Taking to the skies
After exploring his options, Kelly booked a demonstration of the eBee Plus. “We’ve been working with KOREC for 15 years. They know our needs and we’ve always enjoyed good after-sales support,” Kelly said. “So, we spoke with their team, ran a few demos and quickly realized that the data collected by the eBee Plus would pay us back in a matter of months, rather than years.”
The demos led to GRAHAM Construction purchasing an eBee Plus of its own, which Kelly describes as “a big help and the right decision.”
[We] quickly realized that the data collected by the eBee Plus would pay us back in a matter of months, rather than years..
On the ground—and in the air—the eBee Plus helped the project in many ways: it provided a full topographic survey, with GPS, and gave Kelly’s team their starting point. With help from their newly purchased UAV, Kelly’s team could work out the topsoil volume, plus the volume of all their topsoil stock piles. Once they had the topsoil strip model, they would do a weekly measure with the drone, analyse the cost of their earthworks and calculate their weekly cut and fill.
“The eBee has revolutionised the laborious task of measuring our cut and fill each week,” explains Kelly. “Before, our robotic total stations and GPS took us two to three days. Now, we fly the site in half a day.”
Kelly notes that each individual quarry survey is now a 10-minute collection job, versus a half-day on the ground. What’s more, his team are no longer put at risk traversing dangerous sites, where drill and blast occur twice a week.
The benefits continue
It’s no secret that using UAVs has proven a successful decision for GRAHAM Construction. But while implementing drones has proven a smart business move on the ground, the use of UAVs has produced additional financial benefits outside the core job site. For example, with the crossover mapping that Kelly’s team completed, what used to take his team four weeks to do can now be done in less than a day.
[The eBee Plus] is the best money our survey department has ever spent.
“[The crossover mapping] was completed with a ten-minute flight, plus one hour of image processing and an hour to produce the CAD model,” says Kelly. “Compare that to a four-week application for traffic management, a day of manage on the ground, with overnight cone placing, plus the survey itself, and we’re talking about a savings of €5,000 euros ($6,000) on one mission.”
Perhaps that’s why Kelly doesn’t mince words when he says that “[the eBee Plus] is the best money our survey department has ever spent.”
Kelly was also enthusiastic about the additional RGB outputs that his drone provided. “In the past, we might have spent up to £60,000 pounds ($80,000) over the duration of such a project by using helicopters to capture our aerial photography,” he said. “Now, we get that from the drone for free!”
For more information, be sure to read the full case study, How Drones Helped Graham Construction Slash Survey Costs.