The largest infrastructure project in Norway is becoming reality with the construction of the longest railway tunnel of Scandinavia and will be ready in the end of 2021, after employing two tunnel boring machines for the first time in the region.

“Follo line” project will lead to the realization of the longest railway tunnel not only for Norway but also for the entire Scandinavia.

Norwegian railways developed this project on commission by Minister of transport and communication. The project was assigned to the joint venture made by the Spanish Acciona and the Italian Ghella.


The new segment will be 22.5 km long: 20 of these will be two parallel galleries, and it will connect Ski to Oslo central station by high speed trains able to reach the speed 250km/h; in this way they will reduce of 50% the time to connect Oslo to Ski.  8.7 billion Norwegian crowns is the overall value of the project, for which two tunnel boring machines will be used, being the first time these machines will be used in Norway.

Works will also foreseen the modernization of Oslo central station and a new station will be built in Ski: this was done with the purpose to not interfere with the everyday mobility of the two cities.


Simem will take part in this project thanks to the supply of beton plants that will be necessary to produce 140.000 concrete segments for the two galleries. The supply will be made of 3 tower plants- Beton Towers- entirely insulated and equipped with heating system for the materials: this in order to guarantee the production in extremely cold temperature, for an overall production of concrete of 500.000 m3.

The construction will be executing during 30 months starting from the beginning of works during spring 2016.


The construction of the two underground galleries must take into consideration several restrictions due to the preservation of the Medieval Park of Oslo with its historical and landscape importance


It has been choosen the coverage of the galleries along with concrete segment thanks to their lower maintenance if compared with the traditional projections of concrete, and for the longer duration they have. The concrete batching plants to produce them has been installed in Asland, a rural area near Oslo.


Simem choose this solution because of its modularity and its flexibility that fit in a perfect way the size of the construction site. Furthermore, this solution embraces perfectly power supply system of the aggregates upstream and the production of the concrete segment, highly automated, downstream.


During the construction of the galleries, the executor of the work are obliged to reuse more than 10-11 ton of fragmented rock in the production of concrete segments, this in order to reduce the environmental impact and to minimize the cost due to the transport of construction material.

To pursue these results any system installed in Simem towers for material movement, for material storage, for dosage and for mixing is provided with the necessary device to work with fragmented material with high hardness.