We are responsible for delivering the largest and most complex part of the project, providing a range of multidisciplinary services including tender documents, detailed design, project management and technical support during construction. Its three contracts cover about 2km of the line – the Norrmalm Tunnel, Norrström Tunnel and City Station.
Linking the City Station with the existing blue metro line involved blasting a connection tunnel through an area of bedrock that measured just 3m across, within a fixed four-month window.
We also demonstrated our market-leading expertise in the latest Building Information Modelling (BIM) tools. The number of tunnels, all going in different directions, could not be drawn in 2D, so 3D CAD was used to get the correct design. Then, all the geotechnical surveys, rock surveys and other information were added to the model, and it was used for collaboration between different disciplines.
The project’s geotechnical models are the most complex ever run in Sweden.