A Chinese TBM manufactured by CREG is to be used to excavate the subaqueous road link in Świnoujście, Poland, a city located on several dozen islands. Austrian contractor Porr, as the lead of a joint venture with Gülermak of Turkey and Energopol Szczecin of Poland, will excavate the road link under the Swine River to connect two of the largest islands of the city. According to Lucyna Roszyk, a spokesperson for Porr, the plan is to launch the TBM in March 2021.

China-made TBM for Świnoujście road link

The central 1.5km length of the 3.2km long, two-lane bi-directional tunnel will be with excavated by the 12m diameter CREG slurry TBM at up to 38m below sea level at its deepest point. It will pass through fine sand and fine-medium sand with gravel at the landfalls, while below the Swine River the main deposits are fine-medium sand with gravel and over-conolidated sandy clay with gravel and chalk. To better cope with the geology, the machine design includes a cutterhead structure with a large opening ratio, a device for continuous wear detection of the cutterhead and cutters, a pipe extension system with zero slurry spilling, and a special articulation structure and cutterhead retraction for ease of steering.

Preparation of the TBM launch site

“Despite the coronavirus pandemic, the machine was produced according to the plan,” said Roszyk. “Most recently, the TBM underwent factory acceptance tests at the production facility, with all the tests relayed via video streaming from China, which allows us to proceed with its disassembly and transportation from China to Świnoujście. The TBM will be shipped as 129 components, with a total weight of 3,176 tonnes, taking about 60 days to complete the journey, of which 45 days will be at sea. Components are expected to arrive in late September with assembly in the 23m deep x 120m long x 19m wide launch shaft taking about three months. We plan to begin excavation in March 2021, according to our schedule, and should take about six to seven months to breakthrough.” Under the plan, construction is to be completed in September 2022, four years after work began.

Production of the lining segments will be in an on-site casting yard about 400m from the TBM launch shaft. “When excavation begins, we must have 200 complete rings, or about 1,600 lining segments, in storage,” said Roszyk. “There are two types of segments. Shorter 1.5m wide rings, will be used through a curve of 300m radius with rings of 2m wide segments used on the straight sections and through an exit curve of 500m radius.” Segments will be cast using rebar cage reinforcement and C50/60 concrete. “The main consideration is that the concrete segments will be exposure to salt sea water. For this reason the concrete is specified as XS2 and XA2,” she said.

TBM will excavate a single tube two lane bidirectional undersea road link

The Świnoujście TBM is is the largest slurry TBM exported from China to Europe and is the first slurry shield project by Porr in Poland. The Austrian company has worked on a number of tunnel projects in the Polish market, including a contract in the south-western part of the country to design and construct the S3 express road section 3 on which two tunnels with lengths of about 2.3km and 320m are to be built.

Świnoujście is located on 44 islands, with three of them inhabited: Uznam, Wolin, and Karsibór. About 80% or 41,000 residents of the city live on Uznam Island where most of tourism industry is also concentrated. Transportation between the islands of Uznam and Wolin is currently by ferry services which employ outdated vessels. Due to this, Świnoujście is periodically cut off from the rest of the country during unfavorable weather conditions. Świnoujście has obtained funding from the European Union which will finance 85% of the €411 million project.

A new TBM road tunnel for the island city of Świnoujście in Poland is to be completed under a deal worth €185.3 million by a consortium led by Porr of Austria. The tunnel, under the Swine River, is set to connect two of the city’s largest islands. Together with Porr, the consortium comprises Turkey-based Gülermak, and Polish company Energopol Szczecin.

Świnoujście city is built on several islands

The total length of the project is about 3.2km with a 1.44km slurry TBM drive under the river. A TBM of 13.5m diameter is needed to excavate a single tube tunnel to house two 3.5m wide traffic lanes for bi-directional traffic. Evacuation niches fitted with staircases will provide the possibility for drivers and passengers to get from the road level down to the fresh air channel located under the road deck to permit evacuation of the tunnel during emergencies.

Initially, the project was to be completed by a consortium of Astaldi and Ghella of Italy but the two companies decided to pull out of the contract. The decision was reportedly caused by the fact that, since the proposal by the two companies was selected, the costs of labor and materials had increased significantly and caused an increase in the costs of the necessary construction work.

Porr Chief Executive Karl-Heinz Strauss told TunnelTalk that excavation using a slurry shield is the only way to construct the tunnel under the river. “The emergency niches will be situated on one side of the tunnel and will be broken out of the segmentally lined tunnel and excavated under ground freezing support.

Construction of the project is expected to take 48 months, allowing the investment to be completed in Autumn 2022. City municipal authorities said that the tunnel design is to be ready by July 2019.

Project will create a fixed link between the city’s main islands

Asked about the company’s experience in carrying out similar investments in the region, Strauss said that Porr has executed a number of tunnel projects in countries including Austria, Germany, Qatar, Switzerland, the UK, and Norway, among others. The company is well positioned in the tunnelling sector in Poland where it recently signed another contract for the design and construction of section 3 of the S3 express road project in the southwest of the country on which two tunnels, of 2.3km and 320m long, are to be built.

"We have a strong track record with slurry shield operations,” said Strauss. “In the course of the H3-4 railway project on the Lower Inn Valley access route in the Tyrolean Alpine region to the Brenner base tunnel, Porr completed the tunnel using a 13.1m diameter slurry shield. The tunnel alignment was completely below the groundwater level and predominantly in sandy or gravelly loose soils with high and rapidly changing permeabilities."

Karl-Heinz Strauss, Porr CEO

In the UK, the company is in joint venture with Skanska and Dutch pipeline company A.Hak to complete the 5km long x 4m diameter gas main pipeline tunnel under the Humber Estuary using a Herrenknecht 4.4m slurry Mixshield and a segmental lining.

The project in Świnoujście is the second TBM highway tunnel under a river in Poland. The first is the 12.5m diameter x 1.3km long highway link under the Vistula River in Gdansk on the Polish Baltic Sea shore, which opened to traffic in 2016. Commissioned by local municipal utility Gdanskie Inwestycje Komunalne, the project was completed by a consortium led by OHL Obrascon Huarte Lain of Spain using a Herrenknecht TBM. At its lowest point the tunnel is 35m below the water surface. At the time, the project was the largest diameter tunnel in Poland. These include the TBM railway tunnel project in the city of Lodz.

A significant portion of the Swine Tunnel investment is secured with funding from the European Union. The Cohesion Fund of the European Commission is financing a wide range of infrastructure projects in Poland under its 2014-2020 perspective and as much as €82.5 billion is available for the country in the six-year period. A significant share of these funds is to be spent on new roads and railway projects.

What distinuguishes the Swine Tunnel project, according to Professor Anna Siemińska-Lewandowska, Vice Dean for Scientific Research at the Civil Engineering Faculty of the Warsaw University of Technology, is the relatively large 13.5m diameter of the TBM. "There are TBMs of 15m and 17m diameter,” said Siemińska-Lewandowska, “but for European standards, this is a large slurry type machine. The challenge here will be to ensure sufficient stability for the tunnel face during excavation."

TBM used by Porr for UK Humber drive project

"There have been similar projects carried out in our region,” she added. “The slurry TBM tunnel under the Elbe River in Germany in the early 2000s has much in common with the Świnoujście project, as they are both located in lowlands. The project will mark a milestone for Poland-based tunneling,” said Siemińska-Lewandowska. “It could also bring great economic benefits to the Polish economy. Owing to it, the prices of land and real estate will grow in this part of the country, similar to what has happened in Gdańsk after opening the road tunnel under the Vistula River."

Świnoujście is located on 44 islands, only three of which are inhabited: Uznam, Wolin, and Karsibór. As much as 80% of the city’s 41,000 population lives on the Uznam Island where most of the tourism industry is also concentrated. Currently, transportation between the islands of Uznam and Wolin is ensured by two ferry lines, which employ outdated vessels, according to the municipality.

“Long lines of passengers who want to board the ferries, particularly during the summer, act as a deterrent and have a negative impact on the city’s image,” explains a statement by municipal authorities. “In addition to this, there are times during unfavorable weather when Świnoujście is cut off from the rest of the country, which can be dangerous to the city. Building a permanent connection will bring a solution to these problems."