Proposed British Isles fixed sea link connections


There have been a number of proposed fixed connections—road or rail, bridge or tunnel—connecting the islands of Ireland and Great Britain, as well as other smaller islands in the British Isles.

Development history of Great Britain/Ireland proposed connections

Pre-20th century proposals

The failure of the Union Bill 1799 prompted a satirical description of a proposal by "architect" William Pitt "to build a bridge from Holyhead to the Hill of Howth."
Between 1886 and 1900, proposals for a link to Scotland were "seriously explored by engineers, industrialists, and Unionist politicians".
In 1885, Irish Builder and Engineer said a tunnel under the Irish Sea had been discussed "for some time back". In 1890, engineer Luke Livingston Macassey outlined a Stranraer–Belfast link by tunnel, submerged "tubular bridge", or solid causeway. In 1897 a British firm applied for £15,000 towards the cost of carrying out borings and soundings in the North Channel to see if a tunnel between Ireland and Scotland was viable. The link would have been of immense commercial benefit, was significant strategically and would have meant faster transatlantic travel from the United Kingdom, via Galway and other ports in Ireland. When Hugh Arnold-Foster asked in the Commons in 1897 about a North Channel tunnel, Arthur Balfour said "the financial aspects... are not of a very promising character".

20th century

In 1915, a tunnel was proposed by Gershom Stewart as a defence against a German U-boat blockade of Ireland but dismissed by H. H. Asquith as "hardly practicable in the present circumstances". In 1918, Stewart proposed that German prisoners of war might dig the tunnel; Bonar Law said the Select Committee on Transport could consider the matter.
The Senate of Northern Ireland debated a North Channel Tunnel on 25 May 1954. In 1956 Harford Hyde, Unionist Westminster MP for North Belfast, raised a motion in the UK House of Commons for a tunnel across the North Channel. In 1980, John Biggs-Davison suggested European Economic Community involvement in a North Channel tunnel; Philip Goodhart said no tunnel was planned.
In 1988, John Wilson, the Irish Minister for Tourism and Transport, said his department estimated an Irish Sea tunnel would cost twice as much as the English Channel Tunnel and generate one fifth of the revenue, thus being economically unviable. In 1997–98, the Department of Public Enterprise refused to fund a feasibility study requested by the engineering firm Symonds to build an immersed tube tunnel.

21st century

Symonds revived the plan in 2000, with an £8 million feasibility study and a £14 billion construction cost estimate. In 2005, the Irish Minister for Transport said he had not studied A Vision of Transport in Ireland in 2050, published in September 2004 by the Irish Academy of Engineering, a report which included a Wexford–Pembroke tunnel.
The proposal of building a bridge between Northern Ireland and Scotland is supported by members of a number of UK political parties. DUP MP Sammy Wilson compared the idea to the approved Channel Tunnel and HS2 projects. The party made a feasibility study into a tunnel or enclosed bridge a precondition to coalition support in the event of a hung parliament in the 2015 election, and again reiterated the potential for a sea bridge in January 2018. In January 2018, leading figures in the Democratic Unionist Party revived calls for a bridge or tunnel between Larne in County Antrim and Dumfries and Galloway; the estimated £20 billion cost of the project would make it among the biggest infrastructure projects in UK history. The link was proposed by Wilson and Simon Hamilton, a former minister for the party in the Stormont administration.
The idea has been further endorsed as a potential solution to boost the economies of Scotland and Northern Ireland after Brexit.

Late 2010s "Celtic Crossing"

The idea for a Scotland to Northern Ireland Bridge, sometimes branded in the press as the Celtic Crossing or Irish Sea Bridge, was revived in 2018, by Professor Alan Dunlop at the University of Liverpool. He proposed a combined road and rail crossing between Portpatrick, in Dumfries and Galloway, and Larne in Northern Ireland, stating that "the coastline between each country is more sheltered and the waterway better protected" than the English Channel, where, as Foreign Secretary, Boris Johnson had proposed a bridge. He suggested that this would create a 'Celtic powerhouse' due to the potential for an increase in trade between the two countries, and the increase in investment from the construction of the project which he put at between £15 billion and £20 billion.
By 2020 the British government had begun to officially undertake scoping into the possibility of an Irish Sea Bridge.

Proposed fixed sea links between Great Britain and Ireland

North Channel (Galloway) route

This route has been proposed variously as either a tunnel or a bridge. A 2010 report by the Centre for Cross Border Studies estimated building a bridge between Galloway and Ulster would cost just under £20.5 billion. The proposal would see passengers board trains in Glasgow then cross on the bridge via Stranraer and alight in Belfast or Dublin. A longer bridge already exists between Shanghai and Ningbo in East China. Some political parties in Northern Ireland have included the bridge in their manifesto for some time. However, because of the Beaufort's Dyke sea trench which is approximately deep, this route would be deeper than the southern routes between Wales and Ireland. The sea trench was also used for dumping munitions after World War II, and so would require an expensive cleanup operation. Ronnie Hunter, former chairman of the Institute of Civil Engineers Scotland, suggested that the project was a "stretch but doable". He cited the lack of "soft rock, the chalk and sandstone" as a challenge compared to the construction of the Channel Tunnel. He also suggested that the change in rail gauge between Ireland and Great Britain might pose further concerns. Such a project was considered by railway engineer Luke Livingston Macassey in the 1890s as "a rail link using either a tunnel, a submerged "tubular bridge" or a solid causeway". The north channel crossing was the subject of a 2020 study by the United Kingdom government.

Isle of Man (tunnel) route

There is a possible route for a rail tunnel via Liverpool surfacing on the Isle of Man.

North Channel (Kintyre) route

This is the shortest sea route at around, between Kintyre and County Antrim, but would include either the three hour drive around Loch Fyne and over the landslip-prone Rest and Be Thankful mountain pass, or two further new sea crossings via either the Isle of Arran or Cowal.

Irish Mail route

This route would be about long. Avoiding the Saint George's Channel immediately to the south of the route would keep the sea depth less than 300 feet.

Tuskar route

The Institution of Engineers of Ireland's 2004 Vision of Transport in Ireland in 2050 imagines a tunnel to be built between the ports of Fishguard and Rosslare. This route would be approximately twice the distance of the English Channel Tunnel at. A new container port on the Shannon Estuary linking a freight line to Europe is included. This report also includes ideas for a Belfast–Dublin–Cork high-speed train, and for a new freight line from Rosslare to Shannon.

Proposed and existing fixed sea links between Great Britain and France

Channel Tunnel

Isle of Man