Raised access flooring for all electrical substations on the E4 Stockholm Bypass, on behalf of Bravida

When Bravida was commissioned to equip the E4 Stockholm Bypass with electrical systems, ventilation and lighting, among other installations, it marked the beginning of a multi-year collaboration with Bergvik. Since 2023, Bergvik has supplied a total of 5,252 m² of raised access flooring to all service stations – including electrical, ventilation and pumping stations – in the tunnels between Kungens kurva and Häggvik.

The project places high demands on both materials and technical solutions. The electrical equipment rooms, known as ELDUs, contain high-voltage distribution boards, switchgear and control electronics, among other equipment. All ELDUs are designed according to the same principles to simplify operation and maintenance, while the flooring also needs to be adapted to the complex tunnel environment. In some areas, the floors have also required additional reinforcement to support very heavy transformers weighing up to nine tonnes.

– In a project this complex, with so many people involved and sometimes extremely tight schedules, it is a major advantage to work with people who genuinely want to find solutions and do everything they can to deliver. Bergvik is accommodating, incredibly flexible and everyone is focused on solving the problems that arise, says Henrik Sundström, Production Manager for the Stockholm Bypass project at Bravida.

The conditions and requirements of the project have changed several times. The ability to rethink solutions and adapt has therefore been an important factor throughout the project. On one occasion, a beam of the required dimensions was unavailable, and Henrik Sundström contacted Bergvik for help.

– I called Umut Dursun directly and asked for help. By the following day, Bergvik had arranged a beam in the dimensions we needed. I have no idea how they managed it, but we were able to install the beam later that same day, says Henrik Sundström.

As the supplier of the raised access flooring for the electrical equipment rooms, Bergvik has been involved throughout the entire process, from drawings and manufacturing to delivery and installation. The Iso Floor system has been adapted to meet the project's various requirements, including additional reinforcement and other project-specific solutions.

According to Bravida, Bergvik's short decision-making processes, fast response times and solution-oriented approach have contributed to the success of the project. In addition to Henrik Sundström, Daniel Ekström and, in particular, Bravida electrical design engineer Lars-Olof Olausson have maintained close contact with Umut Dursun and Rasmus Kihlström at Bergvik throughout the project. When the requirements changed and all of the floors had to be redesigned, Bravida's engineers were able to communicate directly with Bergvik's design team, allowing the work to continue without losing momentum.

After just over three years, the project is now virtually complete. The remaining work consists of testing, any necessary adjustments and final inspections.

– It has gone better than expected. The fact that we have been able to stay within the expected timeframes is largely thanks to the close and constructive dialogue we have had with Bergvik throughout the project, says Daniel Ekström, Production Manager for the Stockholm Bypass project at Bravida.

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Facts

Project: E4 Förbifart Stockholm, one of the world's longest road tunnels, running between Kungens kurva and Häggvik.
Customer: Bravida, commissioned by the Swedish Transport Administration to carry out all installations for electrical power supply, lighting and HVAC, as well as water and wastewater systems and fixed fire suppression systems.
Bergvik's delivery: Complete Iso Floor system with project-specific solutions, including engineering, design and installation.
Scope: 5,252 m² of raised access flooring.
Project start: 2023.