Railway tunnel between Finland and Estonia

Finest Bay Area – Railway Tunnel between Finland and Estonia


Project facts

Client: Finest Bay Area Development Oy

Project Period: 2018–

Project Type: High Speed Railway tunnel

Finest Bay Area Development Oy is planning to build an undersea high speed railway tunnel between Finland and Estonia. The tunnel shortens the traveling time between the two countries to approximately 20 minutes, connecting the Helsinki and Tallinn capital regions into one metropolitan area. The project improves the opportunities for collaboration between the cities, and enables the area to develop into a significant hub connecting Asia and Europe.

Pöyry is responsible for the Environmental Impact Assessment (EIA) process for the project. Together with AINS Group, Pöyry is also part of the consortium responsible for the conceptual design of the project. Both the EIA process planning and the conceptual design began in May 2018.

World’s Longest Railway Tunnel

The tunnel will be 100 kilometres long, which would make it the world’s longest railway tunnel. In the construction phase, the plan is to utilise TBM (Tunnel Boring Machine) technology, complemented by the traditional ‘Drill and Blast’ method. TBM technology is about boring the whole tunnel profile width at once. At the same time, the required concrete elements to support and seal the walls can be installed. TBM technology will be used in this scale for the first time in Finland.

“When we build tunnels we build them with the best partners. Pöyry has excellent skills and knowhow in underground facilities engineering,” says Peter Vesterbacka from Finest Bay Area Development Ltd.

The construction phase is estimated to last roughly 5-9 years. The duration depends on especially the daily boring speed and the possibilities to overlapping buildup and drilling works. The daily boring speed depends on the future development of tunnel boring machinery. The tunnel will be built simultaneously from multiple starting points.

Environmental impacts are assessed extensively and interactively

The environmental impact assessment (EIA) takes into account the project’s environmental risks, use of natural resources, social impacts, environmental health, noise, vibration, ground water impacts as  well as impacts on water quality, flows, water systems, conservation areas and fish and bird species. Also the impacts on traffic systems, land use, community structure, landscape and cultural environment are assessed. There is an expert group of approximately 40 people involved in the project from Pöyry.

The EIA process in Finland and Estonia will be guided by the local legislation of both countries.  The EIA process produces information to the audience and stakeholders and aims to minimise the environmental impacts. EIA is an interactive process, and public events and tenant workshops are an essential part of the process.

Tunnel alignment is defined during the process

Different route options are investigated in the EIA process, in order to find the best tunnel alignment considering the technical, social, environmental and financial aspects. All options include a station on an artificial Island outside Helsinki, and the Helsinki and Tallinn airports are the end stations. The number and locations of the other stations will be defined later.

The railway route options

Further information

Tunnel App
Through Tunnel App, you’ll receive the latest news and invitations to the public events. The app will also be used for questionnaires and feedback collection. You can download the Tunnel App on your smart phone here: