Open Pit Insights — How Survey UAVs Are Essential to Mine & Quarry Workflows

In senseFly’s Integrating Drone Tech into Mine and Quarry Workflows webinar (watch it here), three industry experts discuss how their companies and consulting clients successfully put survey UAV technology to work at open pit mine and quarry sites across the world. They also share how they’ve successfully integrated drones into their respective site workflows, what kind of ROI is possible from using survey drone technology, what benefits surveyors can expect from drones and much more.

For those of you who may have missed the webinar, there’s no need to worry. Below you’ll find the key learnings from the session, as discussed by Adrian Charters, Director of Geology, Survey & Air Operations at Land & Minerals Consulting Ltd (LMCL), Sean Jeffreys, Owner and Chief Surveyor at Sean Jeffreys Ltd (ex Barrick Gold) and Glen Heather, Mining Technical Engineer at Imerys.

Learning 1: UAVs improve site safety

Perhaps the most important learning we gathered from the webinar is the way in which survey UAVs are helping to improve site safety by making it easier and safer for surveyors to monitor their work sites more frequently and more accurately.

With the images collected from a drone flight—and the subsequent point clouds derived from those images—surveyors can better monitor the shifting nature of a mine or quarry and spot potential safety hazards before they intensify.

“This used to be a very tedious exercise you would do with a total station, explained Adrian Charters of Land & Minerals Consulting. “But with the use of a UAVs, it’s excellent. And we now regularly fly both new and old quarries once a month to look for geotechnical issues.

By using UAVs, surveyors, geologists and mining engineers no longer need to traverse dangerous areas on foot. Instead, they can send a drone to capture the data they need from a safe distance.

One of the best examples given during the webinar came from Adrian, who shared how his team—with help from their drones—observed a potentially hazardous rock formation, featuring several dilated joints, at the Bardon Hill quarry in the UK.

“Data collection is almost easy. Drones make it too easy.”

Because the rock formation in question was high up in the multiple face and bench system, Adrian used the imagery captured by their drone to identify the formation and then take the necessary steps to alleviate the problem before it posed a real danger to worker safety.

By using his drone’s 3D point cloud output (generated by processing the UAV’s images in Agisoft PhotoScan software), his team was able to calculate the rough tonnage of the formation (about 245 tons). The block was then categorized as a potential hazard and the catch fall bench was pushed back 20 meters.

Adrian also explained how he uses his survey UAV’s point clouds to generate pseudo-sections down through the point cloud.

“The point clouds are fantastic for this, particularly if you model them in arbitrary mode,” he said. “We tend to use Agisoft. That allows you to model overhangs, etc… We generate hundreds of sections, and from this, we can generate iterative rock fall scenarios.”

Learning 2:  The importance of providing relevant data

It’s no secret that UAVs make it easier to collect vast amounts of geospatial data. But that data is virtually useless if it’s not client-relevant and, ultimately, easy to work with and act upon.

Glen Heather of Imerys summarised this best during his presentation when he explained that, while drones have made the data collection process easier, they’ve also made it even more important to organise this data and to provide it to the end user—i.e. clients—in a format that they can work with.

“One thing that I wanted to really hammer home is that you can collect a lot of data,” he said. “Data collection is almost easy. Drones make it too easy,” Glen explained. “What you really need to make sure of though is that this data is digestible, easily accessible for everyone and all in one place.”

This view was also shared by Adrian. “If you can give your client a point cloud, that’s great, so long as they can process it and use it in some way,” he said.

So, while survey UAVs are making it easier than ever to capture valuable site data, that data could potentially be almost useless if the end client is unable to use it.

Learning 3: UAVs save time

The presenters were also keen to share how survey UAVs have helped save time by giving them access to mine areas that may have otherwise been difficult or altogether impossible to access using terrestrial survey instruments.

Adrian also brought up an important point regarding the benefits of using a fixed-wing drone in certain situations rather than a quadcopter.

“We did our initial survey in 2015 using a geocopter. It took 28 separate flights, three-and-a-half days on-site and a major issue was hot battery recharge,” Adrian recalled. “So then in 2016, the client said we had to reduce our turnaround time down to three days—from survey to producing our final plans with volumetrics. So that’s when we purchased our first eBee RTK.”

Working for Imerys in the China clay pits of Cornwall, England, Glen Heather explained how conditions aren’t always favorable, and that accessing specific parts of the pits can be difficult on foot, which is why remote-sensing technology (in the form of mining drones) has helped save time and proven so helpful.

“As the drone programme gets into swing, you start seeing the reduction of the cost and the savings coming through.”

Sean Jeffreys agreed, adding that accessing certain areas in a China clay pit, such as the kind found at Imerys’ site in Cornwall, would have been near impossible with anything other than a drone, particularly if the site was subject to frequent rainfall. Of course, being unable to access a specific area of a mine or quarry—therefore having to wait for conditions to improve—would slow down a survey team’s work and ultimately increase operational costs.

And as Adrian mentioned, “If you compare with drones to traditional techniques, we now have our data on demand. reduced lead times, because we’ve brought the service in-house, and because you can get a drone in the air much quicker than with other methods.”

Learning 4: UAVs help cut costs

Of course, saving time equates to fewer man-hours on-site, meaning economies can be made. This, said our speakers, results in survey UAVs providing a positive return on investment.

During his presentation, Sean shared a slide (below) of a drone program he helped implement at Barrick Gold’s Pueblo Viejo mine in the Dominican Republic. The slide shows the company’s initial drone outlay and the subsequent savings over a four-year period.

The cost savings enjoyed by Barrick Gold’s Pueblo Viejo Mine over a four year period after implementing its drone program.

“The results in this slide are quite typical for a company implementing a drone program into its operation. The first year always attracts the highest costs when you’re buying the software, the hardware and the training,” he said. “And then, as the drone program gets into full swing, you start seeing the reduction of the cost and the savings coming through.”

Adrian shared the same experience, explaining that the income and savings from his drones more than made up for the initial financial outlay.

“If you look at your cost per flight or per data set, due to the regularity of the flights you can carry out with drones, you inevitably will have higher costs if you utilise just aerial LiDAR, on a flight-by-flight basis.”

“Our income went up substantially,” he said. “If you average it out over the three years so far, we’re getting an ROI of 195 percent. So, it’s significant, and it’s great hardware—highly reliable.”

Meanwhile, Glen explained that while drone technology has its limitations—citing weather as an operational limitation—the cost-benefit easily outweighs such limitations, especially when you factor in alternative methods, such as expensive aerial LiDAR.

“If you look at your cost per flight or per data set, due to the regularity of the flights you can carry out with drones, you inevitably will have higher costs if you utilize just aerial LiDAR, on a flight-by-flight basis.”

Learning 5: UAV implementation can be challenging—but worth it

While some in the industry might view survey or mining UAVs as unproven technology, Sean’s extensive experience has led him to believe that drones already are or should be part of any successful mining operation.

Sean began his presentation with a quote from Iain Allen, now Program Director of Innovation at Barrick Gold, who said, “UAVs in mining are no longer considered innovative. They’re now standard operating procedure.”

Sean also provided insight into how mining operations can implement successful enterprise-drone programs of their own. He talked about needing the support of vendors, such as senseFly, so that as a manufacturer evolves their product—in this case —so too will that partner relationship grow.

Sean also spoke of the ideal scenario being both the involvement of corporate leadership and workers on the ground and how important it is to transfer the knowledge or “benefits” of the technology across the company.

“We’re in an age where innovation is key. Every day, you can come up with new ways of doing things,” he said. “The challenge, really, is to take those new ideas and integrate them into the mining or quarrying workflows, and sometimes therein lies the challenge. Inevitably, we’re there to improve the day to day, to make people’s lives easier.”

In Sean’s view, mine management should identify the correct resources and thereafter remain open to innovation. But he also cautioned that while innovation brings about positive change, it is a multi-step process that is not without failures. The important thing is for organizations and individuals to learn from such failures. “…That’s how you improve—learning from your own mistakes and from others,” he concludes.

Learning 6: Survey UAVs can lead to unexpected benefits and opportunities

While there are some more obvious benefits and applications to using survey UAVs, it turns out there are some rather unexpected ones as well!

For example, Sean detailed the numerous ways his mining clients employ drones at worksites across the globe.

“These may seem obvious, but some of them may be new,” he explained. “The first obvious application was for month-end reconciliations, where we did pits and quarry volumes and stockpile volumes. We looked at construction, dam wall constructions and other areas where contractors were involved, and for communication of mine plans.”

“If you’d asked a geologist if he would be involved in HBO’s Game of Thrones a few years ago, he would say, no. But you never know what might happen with a drone!”

“A by-product of the UAV coverage though was slope monitoring,” Sean added. “It became quite evident that this data is of sufficient accuracy and reliability to start using drones.”

Finally, while not as commonplace, Adrian also shared a fun story about how using survey UAVs led to an unexpected opportunity: becoming involved with the production of HBO’s Game of Thrones series.

Picture of the Game of Thrones film set with added CGI effects. Note the actors’ proximity to rockfaces, which required rockfall mesh (not visible). (Photo courtesy of Blood & Fire Productions Ltd.)

Adrian’s company was contracted to carry out geotechnical assessments of the cliff faces within the film set of Castle Black, as well as helping to design the film set itself by making rock fall recommendations.

“If you’d asked a geologist if he would be involved in HBO’s Game of Thrones a few years ago, he would say, no. But you never know what might happen with a drone!”

Watch senseFly’s webinar: Integrating Drone Tech into Mine and Quarry Workflows