January 20, 2022
"Burkland, Nygruvan, Dalby, and now we’re going down to Cecilia...."
Mattias Dömstedt rattles around the different parts of the mine while he’s used to driving the car through the long tunnels. He is the Technical Production Coordinator for Zinkgruvan Mining’s project to start drilling via teleremote via a dedicated 4G network and we are on our way down to the level where the Epiroc Simba E7 rig is operating, some 350 meters underground.
Dömstedt stops the car and we get out. At the very end of the mine path, the Simba drills at full capacity, but the cab is empty.
"Right now we’re in the area that constitutes the first stage of the project. Stage two of the network is practically complete, and we have already started work on the third stage," says Project Manager Håkan Mann.
He is notably enthusiastic.
“So far, it’s gone almost too well to be true.”
It was early spring 2021 that Zinkgruvan Mining, working in conjunction with its vendors Epiroc and IT, and telecom operator Telia, first connected its Simba E7 rig to an LTE (Long Term Evolution) network. Since then, remote production has taken off like a shot in the areas where the LTE network has been commissioned, although the drilling that takes place over the network is still considered to be a test and is not measured against any specific targets.
"So far, we’ve drilled seven pallets remotely. It runs very smoothly, and as soon as we find something that doesn't work, I can call the Epiroc service engineer who has been there from the start," says operator Jocke Lindblad.
He monitors the rig from a quiet above-ground office, next to a window where daylight flows in and with colleagues who occasionally stick their heads round the door to exchange a few words.
"I like being down in the mine too, but it’s certainly safer and better for the body to sit here. It’s nice to be able to take a coffee break or get a breath of fresh air when I feel like it," he says.
The fact that the operators do not need to drive down into the mine, except when something is difficult or some servicing is required, means that they can drill an average of four hours more per day.
In purely technical terms, Lindblad can operate the rig from an office in exactly the same way as he would down in the mine. The screens and levers are the same here as on the rig.
"The only difference is that I can't hear the drill. But you do have to keep an close watch on the measurement values on the display," says Lindblad.
"This will give us better control over our production and reduce our costs. It feels really good. But the greatest gain will be in respect of safety, with our employees having to spend less time in the mine."
Building a dedicated LTE network has been a challenge. It is much harder to bring together a design in a mine than above ground. However, the choice was easy.
"We looked at running automation via Wi-Fi, but since we want the network to work for at least another ten years, why not invest in a system that can handle the demands of the future?" says Craig Griffiths, Mining Manager at Zinkgruvan Mining.
He is convinced that the investment put the mine in a good position for years to come.
"This will give us better control over our production and reduce our costs. It feels really good. But the greatest gain will be in respect of safety, with our employees having to spend less time in the mine."
While the Simba occasionally – under Lindblad’s supervision above ground – changes position for a new drill hole, Mattias Dömstedt and Håkan Mann have time to explain how the technology works, and how the work of installing it has progressed.
"Once complete, the project will have seen about 70 remote radio units, i.e. transmitters and receivers of radio signals in the LTE network, installed in the mine, providing coverage of around 70 kilometers. The LTE network will then be extended as the mine expands The portion of the LTE network currently in operation covers around 15 km," says Mann.
By then, hopefully some time in 2022, it will be possible to run another Simba rig by teleremote, provided that RCS4 can be used via LTE. But Dömstedt, Mann, and their colleagues on the project have already come a long way since the very first tests, which would show whether teleremote over the LTE network actually worked at all.
"We were in Epiroc’s workshop 800 meters down in the mine. We had a remote station in the room next to the rig, and we looked out to see if it was moving around on the rig, and it was," says Dömstedt.
Mann smiles as he recalls what happened. It was an important test. An example of what the LTE network can achieve and inspire the continued development of more things that the network can be used for.
"As we are the first to build something like this, we haven't been able to ask anyone for help, we've had to solve all the problems ourselves along the way."
According to Mann, the key to success lies in clear, short decision-making paths and a responsive way of working where everyone, including partners and suppliers, takes responsibility and is fully committed.
"This is exactly our approach to this project. Everyone involved has had direct contact with each other. Even the operators have been able to talk directly to those building the network.
The close cooperation with Epiroc has been absolutely crucial to the project.
"Our development has gone hand in hand with that of Epiroc. They’ve known that we were going to build an LTE network and then developed their teleremote system accordingly,” says Mann.
Despite the fact that Zinkgruvan is still a long way from bringing home the project, both Mann and Dömstedt are proud of what they have achieved. After completing 6,500 remotely drilled meters, they can confirm that the drilling is more efficient than ever, while the operators are satisfied and happy.
"It’s been fantastic to work on this project. I’ve been working with automation in different ways for four years here in the mine and now have started drilling and see how it has developed – it’s been really fun! Of course, the fact that we're getting such good feedback from the operators makes it even more exciting," says Dömstedt.
Facts Zinkgruvan - Teleremote Drilling over LTE Network
∙ The mine has a total of four Epiroc Simba rigs. At present, one of these is connected via Simba Teleremote.
∙ The first test, which involved controlling the rig remotely over the LTE network, was carried out in December 2020, in Epiroc’s workshop located down in the mine. The remote station was set up in the room next door.
∙ At present, the operator sits in an office above ground and monitors the drilling. In the future, they may move to an office 800 meters down in the mine in order to get closer to the rig.
∙ 6,500 drill meters have now been drilled. The goal is 10,000, after which a thorough evaluation will be carried out.
∙ Thanks to teleremote, Zinkgruvan Mining earns, on average, four extra hours of drilling per day.
∙ In order for the LTE network to work with Simba Teleremote, no extreme speeds are required, although the network must be stable and not exhibit any latency.