The Fornebu Line is one of the largest public transport projects in the capital area in many decades. The new metro will run in a tunnel between Majorstuen and Fornebu, with a total length of 7.7 kilometers and six new stations. When the line is completed, the travel time between Fornebu and Majorstuen will be around 12 minutes.
Geonor has played a central role along this route. The company has supplied and operated a comprehensive system for monitoring groundwater and pore pressure. The measurements provide important information about the conditions below the ground, and help to monitor any changes that may occur as a result of the construction work.
When the contract was awarded, it was the largest in Geonor's history and marked an important breakthrough for the company in monitoring large infrastructure projects.
Geonor's delivery is about making ground conditions measurable over time. The sensors record developments in groundwater levels and pore pressure along the route, and the data is used to monitor how the construction works affect the ground around the tunnels and station areas.
This is particularly important in densely populated areas, where tunneling work may affect existing buildings, technical infrastructure, roads and other structures. If the groundwater level changes, this may have an impact on settlement and stability of the ground in some areas.
Fornebubanen itself describes monitoring of groundwater levels and pore pressure as important information for assessing the need for measures such as injection, waterproof construction or water infiltration.
Information about the conditions below the ground is crucial in a project of this size. It is not just about installing sensors, but about giving the project the best possible decision-making basis throughout the entire construction period.
The Fornebu Line is being built in demanding environments, with tunnel work through both densely populated areas and challenging ground conditions. In 2025, the four major tunnel contracts for the 7.7 kilometer long tunnel were completed . In the same year, the final tunnel penetration was also completed, 55 meters underground at Skøyen.
The project is now moving forward with the construction of stations, technical installations and later testing of the infrastructure.
What makes the assignment special is the combination of size, duration and complexity. The Fornebu Line is a major societal project, and the monitoring will function over many years. This places demands on both technology, professional expertise and operational reliability.
The contract was worth 17 million kroner and runs over nine years. After the actual installation, the work consists of operation, maintenance and follow-up of the monitoring system.
An important part of the delivery is remote monitoring. The sensors collect data automatically, so that developments can be followed without having to check all measurement points manually.
The use of remote monitoring makes it possible to follow developments more efficiently and systematically. It provides a better overview, faster access to data and a better basis for assessing measures if the measurements show changes.
The experience from the Fornebu Line shows how modern measurement technology can be used in large development projects where control of ground conditions is important. Similar systems can also be used in new tunnels, road projects, railway developments, large buildings and other critical infrastructure.
The technology also has relevance outside of urban and transportation projects. Monitoring water pressure, groundwater and ground movements can be important in connection with natural hazards such as floods, landslides and rockfalls.
The need for good data from the ground is increasing. Large construction projects are becoming more complex, and the requirements for documentation, control and risk management are becoming higher. For Geonor, the Fornebu Line is a good example of how instrumentation and remote monitoring can provide concrete value in a large social project.
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