Økern is an area of Oslo that is developing rapidly. On its completion in 2020, the gigantic commercial complex Økern Portal is sure to become a central feature of this section of the city. However, Økern is also a centre for infrastructure under the ground.
- A cable connection on the site, critical to the smooth functioning of the local community, was identified during the project design phase of the Økern Portal commission. Relaying the 300 kV cable had to be completed rapidly to prevent delaying the other parts of the construction process. Infratek delivered the best solution proposal, with the fastest delivery,” relates Kristian Dahl.
The cable is owned and operated by Hafslund Nett, although Statnett holds overarching responsibility.
From subsea cables in the UK to underground cables at Infratek
Having completed his degree in marine technology and cybernetics at the Norwegian University of Science and Technology (NTNU), working with cables was not the most self-evident career choice for Kristian. However, when he landed a job in the UK working with offshore projects and offshore cables, his interest in the area was awakened.
- Before joining Infratek, I worked for DeepOcean where I was involved in major subsea cable projects and wind farms. For example, I worked on a major initiative designed to link the whole of Europe together in a giant electrical grid using subsea cables. One of the places I worked in here was the department tasked with tendering for subsea cable projects, and this was where I began to develop an interest in cables, explains Kristian.
Field engineer, engineering manager, project engineer. Kristian held a variety of positions with plenty of responsibility.
After a few years in the UK, however, he was ready to return home to Norway.
- When the Infratek job opened up, it was a great opportunity and a challenge. I’ve made great strides as a project manager since I joined Infratek, especially with regard to land cable commissions. My work involves a much higher level of cable technology skills than previously, and it’s been a steep learning curve. I was given plenty of responsibility as soon as I started at Infratek, says Kristian.
Collaboration with the world's largest cable manufacturer
Infratek won the Økern project in May. The project was a dream come true for a cable enthusiast, with regard to both project partners and unique cable solutions.
- This project took the form of a working relationship with the Dutch branch of the Italian company Prysmian, one of the biggest cable manufacturers in the world. Infratek was the general contractor, with Prysmian participating as a subcontractor. It’s fascinating to work with the best in the business, adds Kristian.
As early as a month after winning the Økern project, work was already under way to test cables at a facility in the Netherlands.
- A heavy-duty test set-up was established in the Netherlands to confirm that jointing from copper to aluminium worked well, and that there were no problems with jointing cables from two different manufacturers.
At the jointing tests in the Netherlands. Kristian (second from the left) together with Infratek fitters Ulf Vrangen and Arild Wold. To the right, Gerard Tuns a fitter from Prysmian.
- Because the cable we were to lay is so important to the power grid in Oslo, the disconnect window was extremely tight. This meant that the relaying work – involving cutting, relaying along a new line, and jointing the cables – had to be done quickly, and we were operating to tight deadlines. The tests and preliminary work we completed in the Netherlands proved crucial to successful execution,” emphasises Kristian.
From the test set-up in the Netherlands.
The new cable is one of the largest (by cross-section) ever laid in Norway: 3,000 mm2 aluminium with a voltage of 420 kilovolts. The cable was brought online on 19 October.
- The connection process ran smoothly – everything worked the way we wanted. It was an exciting project where we learned a lot and had the chance to work with great people who had all kinds of knowledge to share. Great teamwork every step of the way, says Kristian.
Økern: Infratek crew working hard on relaying and bedding the 300 kV cable.
The new cable line at Økern is now completed; it is 250 metres long, with 36 metres running alongside the pedestrian/cycle path on Lørenveien, 140 metres under Dag Hammarskjølds vei, and the remaining 74 metres routed through a green area.
The project manager can now look forward to taking on a variety of new projects.
- We’ve just completed the Økern project, and I’m currently involved in several tender processes. We’re also working on a temperature measurement commission for Hafslund before starting work on a number of other projects. There’s plenty to keep us busy, which is just the way I like it, he concludes.