Nord Stream 2 Trenchless Shore Crossing

Twin microtunnels beneath the Greifswald Bay

Beneath the shores of northeastern Germany, two parallel micro tunnels have been constructed to create a crucial landfall connection for the Nord Stream 2 gas pipeline. Located in the environmentally sensitive coastal area of the Greifswalder Bodden, the project shows technical precision in challenging site conditions.

At the heart of the works were two trenchless shore crossings, each extending 700 metres and constructed by pipe jacking method. The reinforced concrete sleeve pipes were designed to accommodate the later insertion of the 1.200-millimetre diameter gas pipeline. Running side by side at an axial distance of 10 to 16 metres, both tunnel drives advanced simultaneously using two tunnel boring machines. Due to layers of sand and clay with glacial boulders of rocks, careful planning and controlled execution throughout the construction process were necessary. The marine environment and groundwater pressure of up to 1 bar added further complexity to the execution. Despite these challenges, STRABAG finished the twin tunnel drives with accuracy. 

Scope of Work

• Construction of two trenchless shore crossings 
• Pipe jacking of twin micro tunnels 
• 700 m long drives 
• Installation of reinforced concrete sleeve pipes 
• Operation of two TBMs in challenging marine geology