SUBSEA tunnels linking some of Scotland’s islands could replace ferries and boost local economies by improving connectivity and bringing in more visitors, according to an islands MP.

Angus MacNeil, SNP member for Na h-Eileanan an Iar, has had talks with Norwegian consultants, who have undertaken similar subsea projects in Norway and the Faroe Islands.

He said tunnels were a serious option which would reduce the islands’ dependence on the ferries network and make long-term savings.

“Norconsult are currently working on three subsea projects including a 27km tunnel in Norway which, when completed, will become the world’s longest road tunnel,” he said.

“They say the rocks in Scotland and the islands are similar to rocks found in parts of western Norway so that similar construction methods could be used and they estimate that significant savings could be made. I’ve got some of the rock they’ve dug out and it’s as hard as the rock in the Hebrides.”

MacNeil said there were several options for subsea links, some of which were less practical than others.

“The problem with Mull is it’s quite deep, but if it was the Sound of Harris, from Berneray to Harris, it would be about 8.5km. Barra to Eriskay could be as short as 4.5km depending on if you used one of the islands in the Sound of Barra.

“Mull to Kerrera would be something between 6.8km to 10km, but that’s 200 metres deep and they need about 50 metres of coverage of rock over the tunnel.

“We could also consider Orkney to John o’ Groats at about 13km and reasonably shallow in the Pentland Firth, so there’s a whole lot of stuff that could be done.”

The Norconsult report examines several options, including a link between Skye and the Western Isles, which it said would cost between £250-500 million for a single tube.

Mull is deep, but could still be viable for a tunnel

“Requirements for a two-tube solution for safety reasons will double the costs to some £0.5-1billion,” it said.

“Another subsea tunnel link between Harris and North Uist will considerably reduce the need for ferries to the Western Isles.”

The distance here, from shore to shore, is around 10 km, but a combination of causeway, bridge and tunnel may be feasible, to reduce the tunnel length. MacNeil added: “In the Faroe Islands the users pay and there’s a government subsidy of around 20%. The tunnels are usually financed by American banks or pension funds. It’s almost a case of getting the Scottish Government to put up some of the money and get the Faroese government in to manage it because they have a vast amount of expertise in this.

“Paul Wheelhouse, the Islands Minister, is very interested in this and is planning to visit the Faroes.”

A Transport Scotland spokesperson said: “We have recently launched a consultation for the new National Transport Strategy to help establish the strategic direction for the network in Scotland over the next 20 years and the important issue of connectivity for our islands and remote communities is being considered as part of this.

“Once completed, the NTS will inform the second Strategic Transport Projects Review (STPR2) in identifying the transport interventions required to provide Scotland with a transport network fit for the 21st century.

“Any decisions on future funding of strategic transport infrastructure in Scotland will be informed by the outcomes of STPR2 and through the normal cycle of government spending reviews.”