Irish Sea Tunnel

An Irish Sea Tunnel would link Ireland to Great Britain across the Irish Sea. It has been suggested in the past largely for political reasons. It would be a railway tunnel, similar to the Channel Tunnel across the English Channel. Although the technical problems are by no means insurmountable, it is unlikely to be economically viable in the near future.

Technical issues

Technically, the tunnel would be similar to the Channel Tunnel between Great Britain and France. The Channel Tunnel carries three types of train; Eurostar passenger services, road vehicle-carrying Eurotunnel Shuttle services, and freight trains which are mostly container trains. The Channel Tunnel is standard gauge, electrified with OHLE to a standard voltage (25kV 50Hz AC). It is built to a large loading gauge, and has double track with twin bores and a central service tunnel.

The infrastructure does not stop at the tunnel portals. Road vehicles use motorways for onward travel, trains use railways for a similar purpose. The Irish Sea Tunnel would require similar infrastructure to be built or adapted.

Although high speed trains and freight trains can share the same tracks, this arrangement is far from ideal. The maximum number of paths along a line is achieved if all trains travel at the same speed, but freight trains are slower than high speed passenger trains. This is less of a problem if the line is lightly used, but if it is not it can be overcome by using passing loops to give passenger trains priority, and/or by slowing the passenger trains. Except where expense precludes it therefore (such as in the tunnel itself), freight trains and passenger trains require segregated right of way.

Furthermore, high speed trains require the railway to be straight, but since the trains are light and regenerative braking can be used, gradients are not a problem. Conversely, heavier freight lines need shallow gradients but curves can be used to reduce the grade without significantly slowing the trains. Therefore a high speed line and a freight line may require different routes. Frequently this has been done by building a new high speed line and using the "classic line" usually built during the Victorian era with grade-loathing steam traction in mind for freight trains. However using the classic route, all or in part, may not be desirable on environmental grounds relating to pollution (noise, visual, etc). And if the classic route was used, parts may have to be rebuilt to a larger loading gauge to accommodate continental-sized trains.

To prevent the buildup of exhaust gases, the railway inside the tunnel must be electrified. This means that barring a change of traction, routes leading to the tunnel must also be electrified. However, most lines in Britain and Ireland are not electrified. Some lines might be electrified however due to the ever-increasing price of oil and environmental concerns. Alternatively, hybrid technology trains capable of running off both electric and diesel power may be developed.

One of the major issues for an Irish Sea Tunnel would be the break of gauge between the 4'8½" standard gauge and the 5'3" Irish broad gauge. Standard gauge would be used as it is the European standard. This is an issue especially for freight trains. For passenger trains the passengers would probably change trains in Dublin or Belfast anyway (whichever is closest to the tunnel) as at the French-Spanish border. For freight trains this would have to be overcome by building new standard gauge lines in Ireland, regauging existing lines to standard gauge or dual gauge, the use of variable gauge axles, or a combination of these. Variable gauge axles are expensive, and only be economical as an alternative to regauging/building long sections of track. A small problem, as has been found in Victoria, Australia, is that the difference between standard gauge and Irish broad gauge is too small to allow high speed operation on three-rail dual gauge, and therefore four-rail dual gauge is required.

Though the Channel Tunnel terminal at Cheriton is close to Folkestone and the M20 motorway and the terminal at Fréthun is close Calais and the A16 autoroute, Irish Sea Tunnel terminals need not necessarily be constructed close to the tunnel portals but may be built closer to the main motorway networks. This may be necessary for environmental reasons as railways have less of an environmental impact than motorways. In this case however, new railway line would have to be (re)built from the portals to the terminals.

There will also have to be a freight yards near to the tunnel portals, like the yards at Dollands Moor Freight Yard and at Frethun. These have two purposes. Firstly to allow the inspection of trains prior to traversing the tunnel to ensure they comply with the necessary safety standards and secondly to hold trains while they wait for onward paths.

Possible routes

Four possible routes have at different times been identified, the first two taken together as North Channel routes. These are:

* Kintyre Route(Campbeltown-North East County Antrim)
* Galloway Route (Stranraer-Belfast)
* Irish Mail Route (Holyhead-Dublin)
* Tuskar Route (Fishguard -Rosslare)

North Channel (Kintyre) Route

This is the shortest route at around 12 miles, from the Mull of Kintyre to County Antrim but is very unlikely to be adopted. It would mean constructing a railway or improved roads (or both) following a roundabout route through some mountainous terrain, mainly on the Scottish side but to some extent also on the Irish side. If it ever was adopted it would mainly attract freight traffic, passenger traffic would mostly still use the ferries and planes.

North Channel (Galloway) Route

This would mean going somewhere around Portpatrick, to a location either just north or south of Belfast Lough.

This would result in a shorter length of tunnel than the southern routes (about 21 miles), and one completely within the United Kingdom, though the Irish government and the European Union might reasonably be expected to contribute funds nevertheless. However because of Beaufort's Dyke this route would have to be deeper than the southern routes.

Travel to Belfast would benefit better from such a tunnel. The distance London-Belfast would be about 750 km, hard to go below 3½ hours with high-speed trains. Travel to Belfast from Glasgow, Liverpool, Manchester and most English cities is better suited.

The Dublin-Belfast-Glasgow-Edinburgh route would be possible. However the route between the two capitals London-Dublin is somewhat circuitous and would probably therefore only be viable for a sleeper train.

Currently, Stranraer is only served by the the Stranraer branch of the Glasgow South Western Line, which routes northeast towards Glasgow, and which is single track south of Ayr. With no changes to the network, English bound trains would be have to be routed via Kilmarnock. It may be possible to re-open the former Portpatrick and Wigtownshire Railway to Dumfries via Newton Stewart and New Galloway. However, it is unclear whether this could be done easily, or if this line would be suitable for high speed trains. At Dumfries a connection could be made to the Glasgow South Western Main Line which in turn connects at Carlisle to the West Coast Main Line (for Manchester, Birmingham, London), the Settle-Carlisle Line (for Leeds) and the Tyne Valley Line (for Newcastle). Carlisle could also be connected to a future British High Speed Rail Network, though this connection might be made further south nearer to Manchester. The A77 road heads towards Glasgow, but is part single, part dual, carriageway. The A75 road leads towards Carlisle and M6 Motorway, but is mostly single carriageway. It may be better therefore to site the terminals somewhere along the M6 or M74 motorways -- otherwise it may be necessary to upgrade these roads.

On the Irish side there are two possible sites for the portal, either side of Belfast Lough:

* In County Down near Bangor.
* In County Antrim between Larne and Carrickfergus.

The County Antrim option would connect to the Belfast-Larne railway line and the Dublin-Belfast railway line via Belfast Central station. The County Down option would connect to the Belfast-Bangor railway line, which Belfast Central station, though trains would have to either reverse in or bypass Belfast Central if they were to continue onto the Dublin-Belfast railway line. Both the Belfast-Larne railway line and the Belfast-Bangor railway line are primarily commuter lines however and may not be suitable for conversion. A Belfast-Dublin LGV would be useful in quickening journey times.

Irish Mail Route

Another option is to follow the traditional route of the Irish Mail steamers from North Wales (Holyhead) to Dublin (Dun Laoghaire). The tunnel length would be about 100 km (60 miles). The main London-Dublin route is more direct and high speed trains would be competitive with airlines. Liverpool, Manchester and Birmingham are also available to be served. The distance London-Dublin would be about 550 km, needing about 2½ hours on high-speed trains. This time is very competitive with air travel, although the trains would have to compete on prices with budget airlines.

The British portal of this route would connect to the North Wales Coast Line around Anglesey. The North Wales Coast Line connects North Wales to Crewe (and the West Coast Main Line) via Chester. For most of its length it runs along the North Wales Coast, following the A55 road. The transport corridor is constrained by mountains to the south and by several seaside resort towns.

Increased traffic would mean that capacity along the transport corridor would have to be increased. Essentially there are two options for the location of the terminals:

* A terminal in Wales near the tunnel portal, with the A55 being widened to motorway standard.
* A terminal in England near the M6 motorway, with rebuilt large loading gauge railway between tunnel portal and terminal.

There are no major population centres along this route (for this reason there have been no container trains from Holyhead Port for some years) and therefore most traffic will be between Ireland and England. An English terminal would have environmental benefits as rail is more environmentally friendly than road. However, a Welsh terminal would bring development opportunities for North Wales. Either option would probably require a dedicated high speed railway line anyway.

Most of the route between Crewe and Llandudno Junction is flat along the coast and this would be easy to rebuild. However, further west there are some issues. At Conwy the line skirts Conwy Castle before crossing the River Conway on the Conway Bridge and would probably have to be tunnelled under (this would also make grade separation at Llandudno Junction easier).

From Bangor, the line rises from just above sea level and runs through tunnels before turning sharply and crossing the Menai Strait via the single-tracked Britannia Bridge, 100 feet above the strait. Even if some trains were diverted by reopening the line to Caernarfon, a new crossing of the Menai Strait would probably be required. This could be in tunnel too.

Presently, Holyhead-Liverpool trains travel via a circuitous route from Chester to reach Liverpool. The Wirral Line offers a more direct route via The Wirral but is a commuter line and would be unsuited to very high speed trains. The Borderlands Line crosses the North Wales Coast Line at Shotton station, but this terminates on the Wirral and does not reach Liverpool; current plans see it being integrated into the Wirral Line. A new line running in tunnel under the Dee Estuary, across the Wirral (probably partially in tunnel) and in tunnel under the River Mersey to connect to Liverpool Lime Street would cut journey times. This could be a possible phase 2 project delivered after the main works.

Tuskar Route

The Institute of Engineers of Ireland's 2004 "Vision of Transport in Ireland in 2050" calls for a tunnel to be built between the ports of Fishguard and Rosslare [A Vision of Transport in Ireland in 2050, [http://www.iei.ie/Publications/GetPublicationDetails.pasp?PublicationID=69&Module=Papers&txt_freetext=&RecordsPerPage=1000&PageNumber=1&MenuID=24 IEI report (pdf)] , The Irish Academy of Engineers, 21/12/2004] . This has primarily a main grand vision of a new container port in the Shannon Estuary, linked freight line to Europe.

This report also includes ideas for a Belfast-Dublin-Cork LGV, and for a new freight line from Rosslare to Shannon.

Though London-Dublin and London-Belfast routes would be possible, routes from Birmingham, North West England, Leeds, to Belfast via Dublin between Newcastle and Scotland to Dublin would probably not be competitive.

On the British side, a high speed line duplicating the Great Western Main Line has been proposed [ [http://web.archive.org/web/20041026081304/www.firstgreatwestern.co.uk/news/release.php?item=29 First Great Western: trains, tickets, timetables for London, Bristol, Cardiff, West of England ] ] [ [http://news.bbc.co.uk/1/hi/england/2336467.stm BBC NEWS | England | Rail firm considers 200mph trains ] ] [ [http://news.bbc.co.uk/1/hi/wales/2336375.stm BBC NEWS | Wales | Cardiff to London in just over an hour ] ] . This however is likely to be less of a priority than one running between London, Birmingham and the North West duplicating the West Coast Main Line. Congestion through the Severn Tunnel is already so great that much freight from the Welsh ports has a circuitous route via Gloucester; the increased traffic generated by an Irish Sea Tunnel would demand a new crossing of the Severn Estuary.

The M4 motorway ends near Llanelli. Any motorway extension would pass through rural areas and close to the Pembrokeshire Coast National Park, which would generate opposition. Terminals however could be located further inland.

As the IEI's report notes " [This report's object] was to cast a vision, essentially an optimistic vision, of transport in Ireland in the middle of this twenty-first century". Somewhat bizarrely it also includes a second English Channel Tunnel.

History and politics

The first suggestion of linking Britain to Ireland is in 1895, ["TUNNEL UNDER THE SEA", The Washington Post, May 2, 1897 [http://pqasb.pqarchiver.com/washingtonpost_historical/access/282943272.html?dids=282943272:282943272&FMT=ABS&FMTS=ABS:FT&date=MAY+02%2C+1897&author=&pub=The+Washington+Post&desc=TUNNEL+UNDER+THE+SEA&pqatl=google (Archive link)] ] with a British application 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. This can be seen as unionist move to physically link Great Britain to Ireland.

Sixty years later Harford Hyde, Unionist MP for North Belfast, called for the building of such a tunnel. ["An Irishman's Diary" by Wesley Boyd, [http://www.ireland.com/newspaper/opinion/2004/0207/3742943993DIFEB7.html (Link)] , The Irish Times, Feb 2004 (subscription required)] .

Although their economies have always been closely linked, in 1973 the United Kingdom and the Republic of Ireland both joined the European Union, which brought their economies closer to the rest of Europe. In 1993 the Channel Tunnel opened between Great Britain and France. Technical challenges of constructing a tunnel were overcome. However, the Channel Tunnel was delivered overbudget and predicted traffic levels have never materialised.

A tunnel project has been discussed several times in the Irish Parliament. [Written Answers. - Sea Transport, [http://historical-debates.oireachtas.ie/D/0384/D.0384.198811160027.html (Link)] , Dáil Éireann - Volume 384 - 16 November, 1988] [Written Answers. - Irish Sea Railway Ferry, [http://historical-debates.oireachtas.ie/D/0434/D.0434.199310190089.html (Link)] , Dáil Éireann - Volume 434 - 19 October, 1993] [Written Answers. - Ireland-UK Tunnel, [http://www.oireachtas-debates.gov.ie/plweb-cgi/fastweb?state_id=1140781637&view=oho-view&docrank=44&numhitsfound=315&query=Irish%20sea%20tunnel&query_rule=%28%28$query1%29%3C%3DDATE%3C%3D%28$query2%29%29%20AND%20%28%28$query4%29%29%3ASPEAKER%20AND%20%28%28$query5%29%29%3Aheading%20AND%20%28%28$query6%29%29%3ACATEGORY%20AND%20%28%28$query3%29%29%3Ahouse%20AND%20%28%28$query7%29%29%3Avolume%20AND%20%28%28$query8%29%29%3Acolnumber%20AND%20%28%28$query%29%29&docid=383293&docdb=Debates&dbname=Debates&starthit=25&sorting=none&operator=and&TemplateName=predoc.tmpl&setCookie=1 (Link)] , Dáil Éireann - Volume 517 - 29 March, 2000] [Written Answers - Transport Projects, [http://www.oireachtas-debates.gov.ie/plweb-cgi/fastweb?state_id=1140781475&view=oho-view&docrank=4&numhitsfound=315&query=Irish%20sea%20tunnel&query_rule=%28%28$query1%29%3C%3DDATE%3C%3D%28$query2%29%29%20AND%20%28%28$query4%29%29%3ASPEAKER%20AND%20%28%28$query5%29%29%3Aheading%20AND%20%28%28$query6%29%29%3ACATEGORY%20AND%20%28%28$query3%29%29%3Ahouse%20AND%20%28%28$query7%29%29%3Avolume%20AND%20%28%28$query8%29%29%3Acolnumber%20AND%20%28%28$query%29%29&docid=477035&docdb=Debates&dbname=Debates&sorting=none&operator=and&TemplateName=predoc.tmpl&setCookie=1 (Link)] , Dáil Éireann - Volume 597 - 15 February, 2005] . It has not been mentioned in the British parliament.

Economics and politics

Half of the air traffic at Dublin Airport is to Britain, with 8,300,000 passengers per annum. The Dublin-London air route is the busiest international connection in the European Union and the second busiest in the world, with about 50 daily flights and 4.5 million passengers per annum. The success of the 15 km Oresund Bridge, inaugurated in 2000 and linking Malmö, Sweden and Copenhagen, Denmark, which has led to important economic integration between the two cities, suggests that the Dublin–Holyhead route may be the most promising. [Closing the gap with £1.5bn road-and-rail link, by Walt Kilroy, [http://www.ireland.com/newspaper/ireland/1997/1229/archive.97122900011.html (Link)] , The Irish Times, Mon, Dec 29, 97] . However Holyhead is not a large city and work commuting cannot be expected.

The Channel Tunnel has failed to generate adequate passenger numbers (partially due to low cost airlines). It nowadays however has more passengers than air passengers, if counting those who have end points near London and Paris or Brussels. It is hard to compete with airlines about those passengers who shall go to the airport to change to other planes on longer distances.

If 5 million passengers to/from Dublin have their other end point in England, and half would use train, one could expect 2,5 million passengers, while in 2007, Eurostar carried 8.26 million passengers.

The construction of the Channel Tunnel also illustrated a funding problem, that since it is an all-or-nothing project, the tunnel cannot be built and funded in stages. Therefore cost over-runs (experienced on the Channel Tunnel) cannot be absorbed. Construction would also take a long time to complete. The project therefore would therefore be an expensive long-term high risk investment.

It might be reasonably expected that opposition to the tunnel would come from powerful big business, particularly ferry companies, shipping lines and airlines. NIMBY local interest groups may oppose individual infrastructure changes.

Various Irish government studies have therefore concluded that an Irish Sea tunnel is, as yet, economically unfeasible.

See also

* List of bridge-tunnels
* Saudi-Egypt Causeway
* Bridge of the Horns

References