From silt to stability – The story of Pylon 91 in Oxelösund

26.02.26

In the power line project between Hedenlunda and Oxelösund, every pylon has its own story – and pylon 91 is no exception, a good example of how NYAB tackles technical challenges with experience and precision.

The project involves the construction of two parallel 130 kV lines spanning 80 kilometers. A total of 244 pylons will be installed to supply SSAB’s steel plant in Oxelösund with green electricity for a new electric arc furnace.

“Each pylon has its own conditions. When working with earthworks, surprises can appear along the way,” says Project Manager Mats Olsson at NYAB.

At pylon 91, the team encountered wet clay, a silt material that placed high demands on the foundation. To address the challenge, work began with a test pit, where geologists and NYAB’s team analysed the soil properties. By using geotextile and building up several layers of gravel, the stiffness of the base was improved.

The next step was a pyramid structure with rock fill around the foundation. This design provides stability and prevents settlement. To further reinforce the foundation, steel lamellas were used, ensuring excellent torsional rigidity which is crucial for the pylon to remain stable even under strong winds and heavy loads.

“It’s in situations like these that our competence and experience make the difference,” says Mats Olsson. “We think through the entire chain, from geotechnics to logistics.”

Pylon 91 demonstrates how every part of the project requires its own solution, from analysis to execution. It’s a clear example of how NYAB’s methodology and project management deliver stability, even when conditions are complex.

Read more about how we work on the power line project in Oxelösund as a whole.