HBK and Cowi deploy fibre-optic structural monitoring at Gothenburg's Korsvägen station on the 8km West Link

Danish sensor specialist Hottinger Brüel & Kjær (HBK) and engineering consultancy Cowi have deployed an integrated structural monitoring system at Korsvägen station in Gothenburg, Sweden, as part of the Västlänken (West Link) rail project - an 8km underground railway connection that includes more than 6km of tunnels and three new underground stations^[1].

What the system does

HBK's solution combines fibre-optic sensing, multi-parameter instrumentation and automated data acquisition^[1]. Working with Cowi, the team built a fully automated engineering analysis layer that converts raw sensor readings into decision-ready engineering intelligence^[1].

The system tracks three variables continuously during excavation:

• Strain - to verify load transfer between stressed bedrock and new reinforced concrete support structures
• Temperature - to account for thermal effects on concrete behaviour
• Humidity - to monitor conditions affecting shrinkage and creep^[1]

Dorin Lungu, site manager for concrete works, said the sensors would monitor the concrete columns both during construction and across their 120-year design lifespan^[1].

The instrumentation has been embedded for long-term use, meaning the same hardware that guides excavation decisions will continue monitoring the station once it opens^[1].

Why Korsvägen is the hardest site on the project

Korsvägen is one of the West Link's most technically demanding construction sites, requiring careful management of load transfer between highly stressed bedrock and newly installed reinforced concrete support structures. The station will sit 20 metres below ground beneath a densely populated urban intersection that has served as a major tram hub since the 1880s.

HBK's fibre-optic monitoring made a leaner excavation method viable, turning strain data into Eurocode utilisation ratios engineers could act on. That shift matters commercially: rather than acting as an insurance premium against failure, the monitoring system became the enabling condition for a lower-impact construction method, with its cost set against savings in rock volume, haulage and programme time.

"Major infrastructure projects require confidence in every decision made underground," said Mats Rydén, HBK's business development manager. "At Korsvägen, we're helping project teams move beyond data collection to engineering intelligence."^[1]

Programme and contract context

Trafikverket awarded the E16 Korsvägen station execution contract to Implenia on 29 June 2026 for more than CHF 250 million on a cost-plus reimbursement basis - a model that places a premium on verified structural evidence at every stage. Implenia was also selected by Trafikverket in 2024 to construct a section of the West Link that includes a rail tunnel and the new Haga underground station.

The first operational milestone arrives in December 2026, when the underground section at Gothenburg Central Station opens with four new tracks, initially functioning as a terminus until the tunnel through Haga and Korsvägen is complete. Full completion of the West Link is now expected by December 2030.

The degree to which continuous structural data can compress programme risk - and support cost-plus contract accountability - will be closely watched as Implenia ramps up work at Korsvägen over the next four years.