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Is it time to replace a 9-mile Scottish ferry crossing with a subsea tunnel?

Formed from rocks almost as old as this planet, the Western Isles of Scotland still feel like they are of a different era to other areas in the UK.

It is not just the fact that there are more sheep than people, or that the pace of life is slower than elsewhere, or that crofting is a vital skill. The difficulty in getting around means that the (mostly) fast and (mostly) reliable transport we experience in our day-to-day lives cannot be taken for granted in these parts.

People are reliant on ferries, with The Corran Ferry – which covers the nine miles between Corran and the Ardnamurchan peninsula – carrying more than half a million passengers each year.

Ferries are dependant on good weather, and are not the most efficient mode of transport. So Scottish politicians have been discussing whether it’s time to become less reliant on sea travel and take a leaf out of The Faroe Islands’ book.

The 18 spits of land that make up The Faroe Islands need boats and ferries as transport too. But surprisingly, 87 per cent of their population are now connected with or without the need for people to take to the waves.

Journeys that used to take a day have been reduced to an hour. This is down to the 17 land tunnels and two subsea tunnels that have made traversing the islands faster and easier.

A third subsea tunnel is under construction and due to be completed in December 2020, and work on a fourth will begin soon. The 11km tunnel, which is already under construction, will have three branches, requiring the world’s first subsea roundabout. For safety, the steepest incline in these tunnels will be five per cent.

It will shorten the journey time from the capital, Tórshavn, to Runavík/Strendur from 55km to 17km, saving drivers around 50 minutes. The journey time from Tórshavn to Klaksvík will be reduced by 30 minutes. The cost of the subsea tunnels will be clawed back via tolls for using them.

In Scotland, work on a Scottish Transport Analysis Guide or Stag appraisal is already happening. The Highlands and Islands Transport Partnership, the Highland Council and the Highlands and Islands Enterprise see the Stag appraisal as a key part of assessing the Corran route.

The assessment looks at all options, including a tunnel, a bridge, or replacement of the existing ferry service.

The Corran crossing is just one route that has been highlighted in Scotland. A Shetland councillor recently warned that the island of Whalsay would die a “slow and painful death” if the ferry service worsened. This is a possibility due to proposed cuts to the service, and the councillor suggested that a tunnel or bridge should be considered.

A report claimed the Whalsay tunnel would cost around £143 million (£52 million more than keeping ferries running over the next 30 years). However a Norwegian tunnel expert quoted £76 million.

When you consider that in the past Britain has led the way – with the first underwater tunnel in the world crossing the Thames in London back in the 1800s – it will be interesting to observe what happens over the next few years. Will Scotland stick with ferry crossings, or will new tunnels or bridges go ahead?

If you have an upcoming project and need assistance with the structural side of things, please do get in touch.

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