U4 Subway Line Extension

The U4 subway line will be extended to the new Grasbrook district in Hamburg. The nearly 1,000-meter-long infrastructure project consists of a total of three sections: a railway bridge over the Elbe, a viaduct on the land side, and a two-story bridge with a suspended subway station at Moldauhafen that floats above the water. The design forms a distinct compositional unit with smooth transitions between the three sections and a significant line connecting the entire route.

The extension of the U4 line across the Elbe links the new Grasbrook district on the southern bank of the Norderelbe, which is currently under development, to Hamburg's HafenCity. This means that the long-planned "leap across the Elbe" is now a reality. The new Moldauhafen stop will initially be designed as the terminus of the U4 line, with an extension to Wilhelmsburg already in sight. In order not to visually disrupt the historic Freeport Elbe bridges (Freihafenelbbrücken) in the first section, a lightweight and transparent network arch with dynamically flat steel arches and intersecting carbon hangers was chosen for the new Elbe bridge – a unique and innovative solution in the field of arch bridge construction. After crossing the Elbe, the arches merge into the V-shaped steel supports of the elevated viaduct, which stand in the direction of travel. The distinctive V-shaped supports continue in a loose rhythm to the Moldauhafen subway station. There, the rhythm of the supports condenses into a bridge structure as a truss from the two traffic levels.