In with the new

Ten kilometres south of the Arctic Circle, surrounded by the majestic scenery of northern Norway, PNC Norge AS is creating a new road that will travel through two mountains and over one lake. Home of the midnight sun, the Bratland community is tightly flanked by towering mountains and clear blue fjords. Hundreds of visitors flock here in the summer to walk the varied mountain pathways, swim, sail and fish in the surrounding water. The access roads around the area are narrow enough to make any driver nervous as large trucks clatter past. It is one such road that PNC is revising – Route 17. The existing coastline road is slipping slightly and runs at its narrowest past the Liafjellet, a tall mountain with a steep face. In winter it’s not uncommon to have avalanches close the access road completely, cutting off communities and businesses north of the area. At these times, the only form of transport is by aircraft and boat, both of which are often delayed or cancelled due to poor weather. At the site, project manager Norbert Hoerlein runs operations with energetic confidence. Hoerlein has been working in the tunnelling industry for 20 years, mostly in Austria and Germany. It’s his and PNC’s first tunnel project in Norway.

Since the Norwegian project required a powerful and reliable drill rig, the company decided Sandvik would be the perfect partner to take on the challenge. Site engineer Ines Hagspiel has become all too familiar with the unique tasks PNC faces at the base of the mountains. “The main challenge during the tunnelling process is to get as little overprofile and underprofile as possible,” she says. “That’s why we need a drill rig that is very accurate, so that we only get a minimal theoretical profile.” On site they’re making the most of the latest jumbo, Sandvik DT1131i, and iSURE tunnel management technology alongside Sandvik rock tools, drill bits, rods and training, resulting in an economical, precise and fast drill and blast process. “The new DT1131i was the first jumbo sold to PNC in Norway,” says Åge Nesserstrand, Sandvik Mining and Rock Technology technical support representative for underground tunnelling. “In the beginning, along with the jumbo and 3D scanner, we delivered a package with the rock tools and a container with spare parts, so that they could be sure that production would continue uninterrupted. We also had a training package here for the operators on site.” The common rock here is gneiss and mica schist – old, solid rock, perfect for building tunnels. The Sandvik equipment can drill five-metre blasts at a time – quite a difference from the one- to two-metre blasts Hoerlein is used to in Central Europe.

“The benefit of a 3D scanner is the possibility for immediate reaction, correction and speed of process – that’s the main thing,” he says. “It helps the operator see the contour, if there’s an underprofile or an overprofile, and he or she can react in place in real time. And the scan is like a fingerprint, so during the next round when the scanner makes a scan, it searches for identical points between the point cloud and the previous scan. Then you’re ready for the next round. The whole process of the navigation by scanner is under four minutes. That’s fast.” The technology Sandvik brings is a perfect fit for a new generation of engineers. “These ‘digital natives’ grew up with PlayStations and iPhones, and they have a great interest in the data and researching the new tools,” Hoerlein says. Education and automation are the future of the industry, he says, and with the data and the engineer working in tandem, they’re ready for an advanced level of safety, documentation and accuracy that clients expect. iSURE 3D reporting tools also make it easier to keep clients informed, increasing the trust between client and contractor. PNC believes in a transparent way of working, and this technology helps to make that process simple. “You deliver accurate information about the project in a straightforward way and then you can arrive at solutions together,” Hoerlein says. Hagspiel agrees: “We really like iSURE because we deliver a 3D model of our tunnel to the client,” she says. “With it we can show them where we have underprofile and overprofile and where we may have to drill new holes for reblasting.”

“It’s important to adopt the culture of the country,” Hoerlein says. PNC hopes to bring slab track rail as well as bridge and tunnel construction to Norway to assist with the country’s need for greater infrastructure, and to do it with Sandvik at its side. “Together with Sandvik, we test new products, like the 3D scanner, so that at later stages these products help to bring the tunnel business a step forward,” he says. “We don’t intend to finish this project and disappear. It’s an investment in the future of the country and the company together.”