Submerged Floating Tunnel

The submerged floating tunnel (SFT) project is a global collaborative research project commissioned by the Chinese engineering and construction company China Communications Construction Co., Ltd. (CCCC). The Dutch tunnel and hydraulic experts from TEC and TU Delft have been invited to join force with the Chinese to tackle this global technical challenge. The consortium consists of 7 parties. Besides TEC and TU Delft, 5 parties from China including TIWTE from Tianjing are involved as core partners.

In March and July 2018, two technical visits from China have taken place (see photo on the top). The project contract has been signed in July 2018 by all parties. During summer 2018, Master and Bachelor students performed several experiments with possible prototypes in the Water Lab of the faculty. Four PhD candidates are planned for this project, looking into the overall structure, hydrodynamic effects and risk assessment.

In September 2018, the Dutch delegation attended the SFT project meetings in Tianjing and Zhongshan, China, organised by TIWTE and CCCC. Besides TEC and TU Delft, experts from Marin Research Institute and Trelleborg were also invited to the meeting in Zhongshan for the knowledge exchange. During this visit, TEC and TU Delft visited the SFT 2D small-scale experiment and the large-scale wave and current flume test site in TIWTE, Tianjing. TEC, TU Delft and TIWTE compared each other’s small-scale physical model test results and discussed the medium and large-scale model test plan. 

In 2019, The following PhDs have started:

  • Marcel ‘t Hart, PhD Candidate Risk Assessment, Senior Engineer TEC (started Jan 2019)
  • Gina Torres, PhD Candidate Risk Assessment (started Feb 2019)
  • Pengxu Zou, PhD Candidate Hydrodynamics (started Mar 2019)

The idea of SFT is to place the tunnel underwater, deep enough to avoid water traffic and weather, but not that deep that high water pressure shall become an important issue. As a general rule of thumb, there is potential for floating tunnels instead of other fixed structures on the sea floor for water depths of 50 metres or more.

But this is just theory. Though many countries have shown interest, namely Norway with its very deep fjords, a submerged floating tunnel has never been built.

Airport at sea
In 2018, Professor Bas Jonkman proposed a submerged floating tunnel to link the Netherlands with a yet to be built airport at sea, especially if the airport island is to be constructed in the deeper parts of the North Sea.

The Dutch Parliament has requested a study into the feasibility of a new airport on an artificial island in the North Sea.

Scientific coordinator: Dr. Dirk Jan Peters
Project coordinator: Dr. Ni Yan 

CCCC has four options to choose from..
The Qiongzhou Strait is 30 km wide and 120 m deep and is prone to earthquakes and typhoons
Screenshot from a video depicting the Underwater Floating Tunnel that Norway wants to build. (Image: Vocativ)