Given that tunnels are such a reliable alternative to ferries and other forms of transportation across bodies of water, it is perhaps not surprising that engineers, designers and urban planners are exploring the potential to use tunnels to connect island archipelagos to each other.

Most notably, the Faroe Islands have a remarkable range of undersea tunnels to connect the 18 separate land masses together, with the level of work, expertise, materials and conveyor belts justified by the convenience and success of the scheme.

Because of this, it is not surprising that it has inspired similar undersea tunnel projects, with one of the most recent examples being a set of tunnels to connect the Shetland Islands together that has reached what has been described as a breakthrough stage.

What is the proposal, what investigative and planning work needs to be executed and why should tunnels be used to connect the Shetlands to each other?

Why Connect The Shetland Islands?

The Shetland Islands, an archipelago of 20 inhabited islands, are the most northerly part of the United Kingdom, 50 miles northeast of the Orkneys and 110 miles northeast of mainland Scotland.

As with other similar clusters of islands such as the Faroe Islands near Denmark, the population of 23,000 people primarily commute by ferry between the islands or to Mainland Scotland.

Because of the wind and tide exposure, the ferry service can sometimes be cancelled for safety reasons, and some of the ferry crossings can take a very long time. 

The services from Lerwick to the Scottish city of Aberdeen can take over 12 hours and are typically undertaken as an overnight crossing.

Society relies on consistent access, and businesses are wary of operating in the Shetlands due to the unreliability of commuter crossing networks. It can also potentially hinder emergency medical efforts and force the use of air ambulances which would not be necessary otherwise.

The ferry fleet is well over three decades old, with many of the boats running past their operating life, something that affects the Islands on environmental, social and cultural grounds given the popularity of the Shetlands for tourism as well as communing.

What Is Being Proposed?

An alternative would be a series of undersea tunnels, and there have been plans and proposals for this for decades.

As part of the Shetland Forward project, the Shetland Islands Council has proposed that the current system of short crossings should be replaced by a mixture of road tunnels between major islands and upgraded ferries for the rest.

The level of change this would provide to the Shetland Islands is significant and has been seen in cases such as the Faroe Islands, the cost to build these islands pays for itself far more quickly than many people expect.

The improvement of lifeline services through the use of tunnels helps communities to thrive, and the proposal therefore is to connect Shetland with Yell, as well as Yell with Unst through tunnels, with plans for more projects contingent on the progression of these projects.

What Planning Needs To Be Executed First?

The major breakthrough for the Shetland Tunnels project is the first phase of seismic and sonar investigations around the islands.

These will determine not only if a series of tunnels can be constructed affordably, feasibly and safely but also suggest where they should be constructed to maximise their function, safety and contribution to the Shetland communities.

The Unst and Yell Tunnel Action Groups commissioned Norconsult, the tunnel consultancy firm that helped spearhead very successful tunnel projects in Scandinavia and the Faroe Islands.

Given the track record of Norconsult, this would be the best possible indicator to see if the Shetland tunnels could work in the way that people on the island expect them to.

Their work is set to begin at the end of March, with a report expected by the middle of August which would include ground investigations, tunnel alignment recommendations and overviews of how the tunnels would be expected to look and function.

The comprehensive survey will be completed in 2026, assuming there are no delays or changes to the expected plans.

Whilst this is a major milestone in itself, it also has helped to change the perception of the project from one that has been frequently seen as a pipe dream to one that has significant community support and potential.

Given that other countries and regions have used tunnel projects similar to those proposed in the Shetland Islands to boost their economic, cultural and social capital, the concept of the Shetland tunnels is closer than it ever has been before.