The Citybanan tunnel in Stockholm was inaugurated 10 July 2017. The 6 km long commuter rail tunnel between Tomteboda and Stockholm South has been described as Sweden’s most complicated infrastructure project in modern times. Extensive blasting was necessary close to sensitive buildings and infrastructure.

The reason for the project was because the mainline through central Stockholm only had two tracks. Over the years, this bottleneck has led to delays and disruptions which then propagated throughout the entire country. In the late 80s, other solutions began to be investigated and the final decision was to build a tunnel with dedicated tracks for commuter trains, thus freeing up capacity for other traffic. The result was a doubling of track capacity and more frequent and punctual departures.

Architect Bengt Ahlqvist and his associates focused mainly on Citybanan’s two new stations – Stockholm City and Stockholm Odenplan – and their links to neighbouring metro stations. The idea was to create something underground reminiscent of classier air terminals – plush, spacious and safe – rather than ordinary stations.

  • I think the overall impression is good. It has that air of an airport terminal, just as we’d planned from the beginning. The stations are spacious, and it almost seems as if people take things a little easier. I’m proud of what we’ve created. At the same time, I’m a little bit curious about what people think; I sometimes feel like walking up to them and asking.

Public buildings demand high standards of both durability and design. It’s estimated that around a quarter of a million passengers pass through Stockholm City every day. It’s why terrazzo is used on the floors and some connecting stairs in both stations.

  •  The floors are used heavily and get extremely dirty, so a single colour material is not recommended. Terrazzo’s durability and design possibilities provide major advantages. The ability to vary colours and patterns in so many ways provides both character and recognition. It can be used both for identity and guidance. Used properly, terrazzo becomes very expressive. We were also careful to ensure that the floor went well with the furniture. I feel we’ve succeeded in creating a beautiful, functional setting that is also durable.

Giving stations different identities creates recognition. Stockholm City has warm earth tones and Stockholm Odenplan blue-green colours.

Herrljunga Terrazzo was involved from an early stage in the planning of the Stockholm City station floor design, and also carried out the work. Bengt remembers how employees from the company brought with them bags of aggregate (crushed stone material) and how they tried out colours and patterns together.

  •  We really had fun! Herrljunga Terrazzo was always willing to help and was fantastically cooperative and positive. Although they showed off terrazzo’s potential, they also seemed curious themselves. Whenever we presented ideas, they never said no; the answer was always: Let’s try it! They are also big in their field with excellent resources and extensive experience. This gives us peace of mind.