FinEst Link News

New survey of the Helsinki–Tallinn railway tunnel route


Geological Survey of Finland (GTK) conducted acoustic-seismic surveys of the possible linings for an undersea railway tunnel between Helsinki and Tallinn. The report was commissioned by the Helsinki-Uusimaa Regional Council.

The survey provided a detailed overview of the geological structure of the sea floor basement and deposits between Finland and Estonia. The results are promising, even though there are some areas near the Estonian coust that require additional soundings.

– A new finding was that the crystalline basement sea floor continues all the way to Naissaar and to the shallows near the Estonian coast, Leading Scientific Specialist at GTK, Keijo Nenonen, explains.

This acoustic-seismic survey is first in kind between Helsinki and Tallinn conducted with modern accurate sounding equipment. The survey was made in August 2016 with additional soundings in October and November.

The results of the study have been published in English. The report does not directly comment on the constructability of the basement but provides new and useful information for further surveys.

The feasibility of a Helsinki–Tallinn tunnel is being studied

The soundings bring more information on the FinEst Link project between Finland and Estonia which examines the possibilities of building a railway tunnel.

The next phase is to examine the technical and economic feasibility of the project, in addition to its cost-effectiveness and impacts. Results are to be expected during the present year. The viability of planning the tunnel can be assessed only after receiving these results.

The undersea railway tunnel would be 90 kilometres long and the train journey from Helsinki to Tallinn would take about 30 minutes.

The thorough research work on the feasibility of the tunnel project was enabled by EU funding under the Interreg Central Baltic programme. The overall budget of the two-year FinEst Link project is 1.3 million euros.

The project is led by the Helsinki-Uusimaa Regional Council in cooperation with the City of Helsinki, the Finnish Transport Agency, the City of Tallinn, the Estonian Ministry of Economic Affairs and Communications and the Harju County Government.


> Acoustic-seismic survey along the proposed railway tunnel route options, between Helsinki and Tallinn

More information:

FinEst Link Project Manager  Kari Ruohonen, Helsinki-Uusimaa Regional Coucil, tel. +358 40 5045 170

Senior Advisor Ossi Ikävalko, Geological Survey of Finland,
tel. +358 29 503 2121

Geologist Kimmo Alvi, Geological Survey of Finland, tel. +358 29 503 2115

Photo of the sounding ship Geomari, picture by Geological Survey of Finland

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