Tusker Tunnel

The Tusker Tunnel is a proposed Irish Sea tunnel project aimed at linking the ports of Rosslare and Fishguard located in Ireland and Wales respectively. [ [http://www.iei.ie/uploads/Files/Publications/%7B2E3BF47BB1104E8CB959CC1E3686F56F%7D_IAE%20TRANSPORT%202050%20FINALWEB211204.PDF IAE TRANSPORT 2050 ] ] The project was first proposed by the Institute of Engineers of Ireland in 2004. The tunnel, if completed, would by far be the longest in the world at 80km (50mi) and would cost an estimated €20 billion.

History

The first discussion of linking Ireland to Great Britain was in 1895 when a British application of £15,000 was put forward to carry out borings in the North Channel and surrounding areas to determine weather a tunnel between Great Britain and Ireland was possible. This was considered to be a unionist move to physically link Northern Ireland to Britain.

The building of such a tunnel was called for sixty years later by Harford Hyde, unionist MP for Belfast.

The economies of Ireland and Great Britain have always been closely linked and in 1973 both countries joined the European Union which brought their economies closer to those of the rest of Europe. The Channel Tunnel was opened in 1994 between Britain and France. The many challenges of constructing such a tunnel were overcome although the tunnel was delivered a year late and £2bn ($3.6bn) overbudget. [ [http://news.bbc.co.uk/1/hi/business/4088868.stm BBC NEWS | Business | How Eurotunnel went so wrong ] ]

An Irish Sea tunnel project has been discussed several times in Dáil Éireann, but never in Westminster.

Route

The Institute of Engineers of Ireland's "Vision of Transport in Ireland in 2050" highlights for a tunnel to be built between the ports of Rosslare and Fishguard. This has a primary objective of creating a new container port in the Shannon Estuary and a linked freight line to Britain and Mainland Europe.

Also included in the report are ideas for an LGV between Dublin, Cork and Belfast.

London - Dublin and London - Belfast routes would be possible although routes from Birmingham , North West England , Leeds Newcastle upon Tyne and Scotland to Dublin or Belfast would more than likely not be able to compete with air traffic.

In England, plans to duplicate the Great Western Main Line have been proposed. This however is likely to be less of a priority than one running between London, Birmingham and the North West duplicating the WCML. 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.

Technical issues

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

Track sharing difficulties

High speed trains and freight trains can share the same tracks but this is far from ideal. The maximum number of crossings in the tunnel would be achieved with all trains travelling at the same speed, but freight trains travel at lower speeds than high speed passenger services. This is a smaller problem if the line is lightly used but if not, passing loops (crossing loops) can be used.

Curves/Gradients

High speed trains require the railway to be straight, but since 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.

Electrification

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.

Break of gauge

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 gauge Standard gauge would more than likely 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.

Terminals

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.

Freight yards

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.

ee also

*Channel Tunnel
*World's Longest Tunnels

References