Faroe Islands: How Four Subsea Tunnels Transformed Mobility in the North Atlantic

The Faroe Islands have transformed day-to-day travel across an isolated archipelago through some of the boldest civil engineering in the North Atlantic. Four subsea tunnels cut through rock beneath the seabed, linking islands that once relied on ferries, restricted timetables and unpredictable weather.

Why did the Faroe Islands build roads under the ocean?

Set between Scotland and Iceland, the archipelago comprises 18 islands with steep, mountainous terrain and settlements separated by fjords and narrow sea channels. For many years, a large share of journeys depended on boats-services that could be delayed or cancelled when strong winds and rough seas set in.

By driving tunnels beneath the water, the Faroe Islands were able to create a continuous road network for residents, public services and freight. Today, the four crossings connect seven islands and bring most of the population closer to the main urban centres.

Which four tunnels were built beneath the Atlantic?

Delivered in phases, the programme began with a link between the airport and the island that hosts the capital. With each additional tunnel, reliance on ferries fell and the number of routes that can be completed by car increased:

• Vágatunnilin, opened in 2002, at about 4.9 kilometres;
• Norðoyatunnilin, inaugurated in 2006, at roughly 6.2 kilometres;
• Eysturoyartunnilin, opened in 2020, with 11.2 kilometres of roadway;
• Sandoyartunnilin, inaugurated in 2023, at about 10.8 kilometres.

How was it possible to excavate tunnels below the seabed?

Construction progressed through volcanic rock using drilling and carefully managed blasting. Before excavation started, teams carried out seismic surveys, geological boreholes and ground assessments to pinpoint fractures and anticipate potential water ingress.

As the passages were driven forward, the tunnels were fitted with drainage, ventilation, lighting, communications and monitoring systems. Key components required to keep the crossings operating include:

• pumps to remove infiltrating water;
• emergency exits and designated refuge areas;
• sensors to track traffic;
• ventilation and fire-suppression equipment;
• linings to stabilise sections of rock.

Why does one tunnel have an underwater roundabout?

The Eysturoyartunnilin has three entrances and links Streymoy-where Tórshavn is located-to two destinations on the island of Eysturoy. To manage traffic splitting in different directions, engineers built a roundabout within the underground system, regarded as the first of its kind inside a subsea road tunnel.

At its lowest point, the route reaches 187 metres below sea level. With the new connection in place, the trip between Tórshavn and Runavík fell from around 64 to 16 minutes, while the driving distance was cut from 55 to 17 kilometres.

The tunnels changed residents’ everyday routines

With the Sandoyartunnilin, people on Sandoy can travel at any time without planning their day around ferry departures. The connection has also made it easier to reach jobs, schools, hospitals and other services concentrated on the archipelago’s more populated islands.

Across the Faroe Islands, this underground infrastructure has shortened journeys without being at the mercy of North Atlantic conditions. Together, the four tunnels demonstrate how rock excavation, road planning and safety systems can knit small communities together even when mountains, fjords and open sea stand between them.