Stockholm City line - Submersed tunnel to be opened
Stockholm City Line
The underwater tunnel "Soderstromstunneln" as a connection between Riddarholmen and Sodermalarstrand is about to be opened for further work in the project, as the tunnel elements are safely placed onto its foundation at a depth of 25 meters in Riddarfjarden.
The tunnel consists of three tunnel elements, and each 20 000 ton heavy tunnel element was equipped with three ballast tanks and 13 Grindex pumps. For positioning the tunnel element sideways and in relation to each other, a number of steel wires attached to fixed points was used, and for positioning depth, angle and roll of the tunnel element Grindex pumps were used in each tunnel element to move water between the ballast tanks.
Late september 2013 the last Grindex pumps and ballast tank walls are being removed and the tunnel in its whole length of 300 meter will be connecting the north end at Riddarholmen to the south end at Sodermalarstrand. Grindex pumps are still used as common dewatering pumps in different areas of the construction site, as well one Grindex Magnum functioning as a rescue pump.