Currently, the travel across the islands can only be facilitated by ferry – but this could be changing with the local authority saying that the tunnel project is now ‘well advanced’.
Could it become a reality? And what does Shetland need tunnels for anyway?
What’s the plan?
Shetland is an archipelago containing about 100 islands – 16 of which are inhabited. They include Yell, the second most northerly occupied island in the UK.
It is connected to the Shetland mainland by a three-mile ferry journey which usually takes about 20 minutes, but the ferries can be halted by severe weather or breakdowns.
The island has previously been earmarked for a tunnel, but projects have never moved beyond the proposal stages because of the cost.
Now Councillors are proposing four tunnels be built: from the Mainland to Yell; Yell to Unst; Mainland to Whalsay; and Mainland to Bressay.
Shetland is served by a ferry fleet, with the boats are creaking. The average age of the vessels is 30 years, six years older than the average time in service of Calmac ferries.
Tunnels, while expensive, have a much longer shelf life and could prove cheaper in the long run.
The council’s political leader, councilor Emma Macdonald, said that a solution to inter-island travel problems simply has to be found, and soon.
She said: “The importance of the inter-island transport network to life in Shetland cannot be overestimated.
“It is the very definition of a lifeline service, and is the social and economic backbone of the islands.
READ MORE: The crisis facing Scotland’s most northernly routes
“However, there are a handful of vessels which are already operating past their intended lifespan.
“If they are not replaced now, either by tunnels or new ferries, there is a material risk to lifeline services to Shetland’s islands.”
So could the plan go ahead?
Shetland council is prepared to put its money where its mouth is – and has set aside £700,000 for the project.
The local authority is hoping the Scottish Government will up its commitment to supporting the islands.
The Shetland Island Council has also secured a meeting with Alister Jack, the Scottish Secretary.
Tunnels link the Fareo Islands
How feasible is it?
Cost will be a big factor – An estimate for just one tunnel was put at £17 million. But The cost of replacing the ferry fleet could be as much as £400 million.
READ MORE: Could new tunnels and funding provide answer for Shetland?
The money needed for the tunnels also pales into insignificance when put alongside the two CalMac ferries being built by Ferguson marine Ltd, which currently stands at £300m.
And while on first glance it seems a far-fetched proposal, undersea tunnels are a relatively routine engineering challenge. The Far-flung Faroe Islands, which lie to the north west of Shetland, are joined by 21 tunnels, three of which are subsea.