The City tunnel - Stockholm

City Line will remedy the shortage of tracks at Stockholm Central. For Struktons employees, it implies several years of underground work. Nexans contributes to the delivery of 52 mil wire.

Tunnelbana Stockholm2016 will the trains start test runs and before that, Strukton have had time to install:

  • More than 11,000 meters of traces with 20 gears and a saving cross.
  • Contact rails for the trains.
  • The entire signaling system.
  • 1700 lighting modules for normal, node, evacuate and signal lighting.

A huge project in itself, but according to Karl-Åke Ling it should not be a problem for Strukton Rail to finish the job on time.

– Not if we can get into the tunnels as planned and that the facility is at it should be, ie that all the design is correct, he says. The big challenge lies in planning and logistics. That Strukton so far only has been allowed into two tunnel sections which is located in the middle of the system and not contiguous, requires some mental effort.
– The tunnel's divided into six parts, and there are cables that go through the entire train tracks. But since we will start working in the middle and there are closed walls in the tunnels that are not yet open to us, entails for us to think one step further on what is behind the wall, says Karl-Åke Ling.

– Another difficult problem is to bring down all the rails. It is only possible for us to bring down 20-meter lengths in the center of the tunnel. This means that some days, a large number of trucks has to go down to the tunnel, where there is only one opening.

The 520 000 meter cable (see facts) that is a part of the project is for the most part from Nexans supplied by Ahlsell. Largely, these are for standard cables that will fulfill the project requirements on the fire class and halogen free sheaths. Around 70 per cent of the 30-60 people who work with putting rail and install the associated systems are employed by Strukton, the rest are contractors or contracted resources.

To work in a tunnel is special, says Karl-Åke Ling.

– It is a bit isolated and it almost becomes obfuscation when you are not exposed by to sunlight. One advantage is that you do not have to take the weather and wind in account, he says as he shows us around in the powerful tunnel system below the Norrmalm ending at the new station Stockholm City, which is now being built in the Central Station. Size of the project and that it is being implemented in a tunnel, requires a greater effort of cooperation between the project partners.

– A big lesson for me is how important it is that we work across technology boundaries, so that we do not stand in the way of each other. In smaller projects it is easier to work more by yourself, says Karl-Åke Ling.



Cable Facts City Line

520 000 meters of cable will to be pulled out along the city line:
Signal: 113 930 m
Cable lighting: 111907 m
Power cable: 49 773 m
Cable remote control: 34 398 m
Ground cable 28 270 m
High Voltage Cables: 24 931 m
Telecom cables, ventilation cable m m: 149 791 m
Amout of stainless steel cable labeling trays according to the Swedish Transport Administration and City Line Standard with the facts of each individual cable section: Approximately 45,000

Strukton Rail AB

Strukton Rail builds, maintains, and operates railway systems. The ompany has its roots in Stockholm local traffics former construction department, and in 2007 joined Dutch Strukton Rail as the hundred percent owner in the company. The Swedish headquarters located in Nacka and regional offices  throughout the country. Strukton Rail has about 850 employees in Sweden and an annual turnover of  two billion dollars per year. Constructor's largest  ongoing projects is the City Line in Stockholm, and Söderås Line and commuter trains NO / Krösatåg in Skåne. Group Strukton Rail Headquartered in the Netherlands, Railway operations in seven countries in Europe and ongoing infrastructure worldwide.