U4 extension Horner Geest, Hamburg

On schedule, technically sophisticated, forward-looking: The U4 grows with Drees & Sommer in northeast Hamburg 

It's an important step for public transportation in the Hanseatic city: the U4 subway line will extend northeast of Hamburg in the second construction phase. The central measure involves expanding Horner Rennbahn Station with an additional track and building a junction for the U2 and U4 lines. Additionally, two new tunnel sections, two modern stations, and a turning and storage facility will be built to ensure the line's future operation.  

Construction will be carried out entirely using the open method. The 20 docks will be built using the diaphragm wall method and, in some cases, supplemented by waterproofing DSV bases. The special geometry of the construction site's layout requires precise soil management, well-planned site facilities, and consideration of complex ground conditions. Construction is also taking place in public spaces with ongoing traffic, so it is being carried out in close coordination with utility companies, authorities, and residents. Drees & Sommer is responsible for supervising the special civil engineering work on the project. The focus is on ensuring that the work is carried out in accordance with the contract, schedule, budget, and above all, quality requirements. The experts also provided support with excavation pit management.  

Once the project is complete, around 13,000 people will benefit from direct access to the subway network in Hamburg. This will strengthen the infrastructure and improve mobility in the northeastern part of the city. 

Added value

• Complex excavation pit in public space successfully mastered
• Adherence to schedule despite tight frames and fixed route closures on existing subway lines
• Intensive stakeholder communication 

Services

• Excavation pit management
• Local construction supervision Special civil engineering