Helsinki-Tallinn railway tunnel is a new undersea tunnel proposed to be built across the Gulf of Finland, between the country’s capital Helsinki and Estonia’s capital Tallinn.

The 92km-long tunnel is estimated to be completed at a cost of approximately $14bn (€13bn). Once the tunnel becomes operational between 2030 and 2035, it will provide reliable and rapid transportation between the two capital cities, offering a vital connection between Scandinavia and Central Europe.

Need for the new tunnel between Helsinki and Tallinn

The Gulf of Finland divides Helsinki and Tallinn, and the 80km-long sea route between the cities is currently served by ferries and fast passenger craft with journey times ranging from 1.65h to 2h. More than 7.5 million trips are made by the ferries a year, including scheduled services and leisure travel.

More than eight million people a year traverse the Gulf of Finland and passenger traffic on the route is projected to increase at a rapid pace, reaching 30 million by 2030. The new tunnel is therefore being built to serve the growing number of passengers and leisure travellers between the two cities.

The new tunnel is intended to reduce the journey time from 2h to 30 minutes. The project has been considered viable as an increase of 30% in the current passenger and freight traffic would cover more than half of the project investment.

Helsinki-Tallinn tunnel project details

The Helsinki-Tallinn tunnel development has been initiated under the Finnish Estonian Transport Link (FinEst Link) project, which is partly-financed by the Central Baltic Program. The project is being led by Helsinki-Uusimaa Regional Council in collaboration with the cities of Helsinki and Tallinn, Harju County, Finnish Transport Agency (FTA) and the Estonian Ministry of Economic Affairs and Communications.

The city of Helsinki will assess the impact of the project, while the FTA will analyse the technical and economic requirements of the tunnel’s construction.

Harju County and cities of Helsinki and Tallinn initiated a preliminary feasibility study on Helsinki-Tallinn railway tunnel in April 2014. Completed in February 2015, the study focused on the technical, economical and business viability of the undersea tunnel.

The transport ministries of Finland and Estonia signed a memorandum of understanding (MoU) to co-operate on the FinEst Link project in January 2016.

With a length of 92km, the Helsinki-Tallinn tunnel will become the world’s longest undersea railway tunnel upon its completion. While the proposed tunnel will include 1,435mm tracks, its design has not yet been finalised.

“The city of Helsinki will assess the impact of the project, while the FTA will analyse the technical and economic requirements of the tunnel’s construction.”


The project is expected to receive funding from the European Union (EU), private investors, and the governments of Finland and Estonia.

In June 2016, the EU granted €3.1m ($3.3m) for the feasibility studies of the Helsinki-Tallinn tunnel project and FinEst Smart Mobility project.

Key players involved with Helsinki-Tallinn tunnel project

A consortium of Ramboll Finland, Sito, Strafica, Urban Research and Pöyry Finland was selected to determine the financial viability and impact of the tunnel project, in February 2017. The feasibility report is scheduled to be completed in the second half of 2017.

Sweco Projekt and partners conducted the pre-feasibility study for the project in 2015. A joint venture between Sweco, Amberg Engineering and WSP was awarded a contract to conduct technical and economic feasibility studies for the project in February 2017.

Geological Survey of Finland (GTK) completed acoustic-seismic surveys of the potential linings for the proposed tunnel in 2016.