Over the past year, NCC has laid out miles - and tons - of new cables for Energinet. The first stretch is completed and number two is expected to be completed this fall, while a third will be launched in late August.
The energy grid is in the process of renewing and strengthening the cable network in order to secure the electricity supply to the Copenhagen area in the future. NCC has laid the route from the Avedøreværket to Amager switching station.
The project consisted of approximately 11 km of excavation - 38 km of draft pipes and 34 km of 132 kV cable with a total weight of 340 tons and approximately 4 km bores. These include two large complicated bores during the Kalvebod race and the Royal Golf Club of over two km.
Focus on security
Along the way, longer stretches had to be dug to a depth of over four meters to maintain respect distance to existing lines. Despite major challenges, safety has been the focus, which led to the project receiving Energinet's security award as a nice recognition of the project's joint security responsibility.
The team has since December worked on the route from Glentegården to Svanemøllen switching station. Here the work is challenged by the fact that excavation work takes place in very busy areas, including on Jagtvej, Lyngbyvejen and at Vibenhus Runddel. Here, too, some digging is done at depths of more than four meters.
The distance is 12 km trace, where 36 km of draft pipes have been laid and flushed 36 km of 132 kV cable - converted in weight is 365 tons of cable. Work is expected during the fall.
70 km of 700 tons cable
In total, the two sections contain installation of a total of about 70 km of cable with a total weight of approximately 700 tons, which is done with the so-called Watucab method where the cables are flushed with water. It is a method that NCC has gained considerable experience with.
Work on both routes has been challenged by the fact that many kilometers have been carried out as evening and night work for the sake of traffic.
Third Energinet cable project underway
At the end of August, the team will embark on the third cable project for Energinet. The new section runs from Glentegården switching station to Bellahøj switching station. At the approximately eight km about 24 km of draft pipes and 24 km of 132 kV must be laid with a total weight of about 240 tons. Here, too, NCC will use the Watucab method to wind the cables through the pipes.
"It takes a professional project team to perform as complicated excavations as these projects contain, and it requires skilled collaborators and the best diggers, and we are fortunate to have them" says NCC Area Director Kim Høgh Thomsen. “We face many unforeseen challenges on such some excavation projects, so we also really appreciate having a builder who contributes to the many solutions and changes along the way. We think of it as "our project" and it is vital for a shared success".
About the Watucab method
Watucab is a method where cables are flushed through pipes with water as a transport fluid.
The method, developed in Switzerland, has now been used with great success on two projects. NCC's team has gained extensive experience with the method after laying approximately 70 km of cables in this way.
"The advantages of the method are considerable" says area director Kim Høgh Thomsen of NCC Civil Engineering. "It provides faster momentum and the traffic challenges are resolved quickly, just as the method minimizes the construction period and thus reduces the inconvenience for the citizens of the neighborhood".
The cable network in the Copenhagen area was built back in the 1950s, 60s and 70s, so it needs to be replaced to provide security of supply. Electricity consumption is increasing in the area, and it is therefore also necessary to establish new electricity connections while replacing the wired cables.