Recently, tunnelling started on the US$231m Swinoujscie Tunnel beneath the Swina Strait between the islands of Wola and Uznam in the northwest border of Poland.
Works on the project has been started since September 2018. Gulermak and Porr Consortium are constructing the 1.78km-long tunnel of which 1.48km is being mined by TBM as part of a 3.2km investment that contains two large launch and receiving shafts and two ramps constructed by cut-and-cover and open-trench.
The giant 13.46m-diameter CREG (China Railway Engineering Equipment Company) slurry TBM and an 18-strong crew started excavating from a 120m long by 20m-wide launch shaft.
The manufacture of the precast concrete segmental lining rings has been ongoing over the past few months at a plant located 400m from the launch shaft. This guaranteed about 1,600 segments (200 rings) were available before the construction start.
Once finished, the bi-directional, single tube, 12m internal diameter tunnel will include two road lanes, each 3.5m wide in addition to 2m-wide emergency lanes. At its deepest point, the tunnel will be 38m undersea level and is going to make a direct connection between Uznam and the Polish mainland.
If working 24/7, the TBM is anticipated to finish its excavation in September 2021 by which time it is going to have bored approx. 210,000m3 of soil. The Italy-based SWS is supplying executive design, on-site supervision and final design of the tunnel. The project, of which US$196m has been financed by the European Union, is expected for completion in the last quarter of 2022.