Lötschberg and Gotthard Base Tunnels, Switzerland

The Lötschberg and Gotthard base tunnel project is a transport solution to the increasing traffic levels, environmental impact and safety issues surrounding the existing Lötschberg-Simplon and Gotthard routes.

The routes were constructed as part of efforts to overcome the Alps natural barrier to north-south surface traffic through central Europe, an obstacle tackled by early railway builders with long, often sinuous approaches to tunnels, cut high up at the heads of valleys.

The long, ferocious gradients and long in-tunnel transits encouraged the early adoption of electric traction on most routes. With the Lötschberg-Simplon and the Gotthard rail routes, the latter also a major road route, Switzerland was a focal point for increasing capacity demands.

The 16.4km (10.5m) Gotthard road tunnel opened in 1980 which, with connecting motorways, caused road traffic levels to soar. Up to three-quarters of heavy goods vehicles in Switzerland were transiting the country. The resulting environmental impact was something that the Swiss did not want to repeat, but they were at odds with their surrounding EU-member neighbours over aggressive taxation and controls for road freight.

Later road tunnel accidents were to further encourage the building of two long low-level (base) rail tunnels as a means of raising capacity and lowering transit times.

BASE TUNNEL PROJECT

Plans for a base tunnel on the Gotthard route had been considered since the 1940s. However, it was not until key referenda in 1992 and 1998 that the NRLA project (new rail links through the Alps; also known as NEAT) gained momentum.

Although encountering heavy domestic political opposition, federal backing was given for the simultaneous construction of the Gotthard and Lötschberg base tunnels. Fully funded within Switzerland, the base tunnel project is supported by fees levied on heavy road vehicles, fuel duty, VAT income and loans.

The Gotthard is on the main SBB route from Zürich to Chiasso; the Lötschberg on the BLS main line from Berne to Brig. In a wider context, they connect northern rail routes with those of Italy, with passenger and freight levels both projected for long term increases.

TUNNEL CONNECTIONS

A ceremonial first exploratory construction for the Lötschberg, the shorter of the tunnels, took place in April 1994.The first tunnel breakthrough came in 2002, with a continuous tube established between the end points at Frutigen (Bern canton) and Raron (Wallis / Valais) by April 2005.

To shorten construction times, tunnels have been constructed from several access points. A fifth of the tunnel was driven by a tunnel boring machine, the remainder being blasted.

There are twin-bore, single ballast-free tracks with access points and cross-over chambers. The running tunnels have a 40m separation and are interconnected at 333m intervals. The tunnel was handed over to the Swiss Federal Office for Transport and BLS AG for integration with the national rail network in 2007.

The Gotthard base tunnel's entry points will be at a mean altitude of 550m, indicating the reduced climb compared to that of the present tunnel at 1,100m. The 57km (35.4m) tunnel between Bodio (Ticino) and Erstfeld (Uri) will become the world's longest rail tunnel upon opening. The project also includes the new Zimmerberg and Ceneri tunnels, respectively north and south of the Gotthard.

HIGH SPEED ROLLING STOCK

Except for dedicated rescue vehicles, base tunnels will not directly call for new rolling stock.

Although more train movements will occur, there will be a reduced need for multiple-loco haulage of trains due to the easier routing to the new tunnels. Freight will travel at up to 160km/h (100mph), passenger up to 250km/h (155mph). With tilting trains becoming standard for passenger services, the BLS route will make it possible to cross Switzerland by rail within two hours.

At up to 4,000t and 1,500m long, some of Europe's longest and heaviest freight trains will use the base tunnels. Indicative of the higher speeds that the low level, relatively straight tunnels will offer for future services, the Deutsche Bahn ICE-R set a new Swiss rail record of 280km/h in the new Lötschberg tunnel in December 2007.

SIGNALLING AND SAFETY

The Lötschberg base tunnel uses Level II European Train Control System (ETCS) for in-cab communication via GSM-R radio. There is no in-tunnel signalling. This is backed up by an extensive telephone network.

In addition to the system's 3,200 fire detectors, the tubes linking the running tunnels have their own power supply, fire protection and ventilation. To reduce fire risks, control systems monitor the condition of trains prior to entering the tunnel, transmitted to centres at Raron, Frutigen and BTS higher level control at Spiez.

FUTURE ROUTE USAGE

The two ‘classic’ routes with the original tunnels carrying the Lötschberg and Gotthard names are being retained, partly as they serve communities en route, have proven tourist appeal and still represent secondary/diversionary routes with valuable capacity.

The Lötschberg mountain route is envisaged as having 65 daily train movements, around half that of the base tunnel, of which two-thirds will be freight. Although built with sufficient clearances, the BLS car carrying train service will continue between Kandersteg and Goppenstein.

The Lötschberg route will work towards complete fitting out and full operation from an initial opening in June 2007 and more extensive operations from December. The main turn out from the new route into the Rhone valley is near Visp, joining the eastbound Geneva-Brig line. Infrastructure allows for a westbound connection to be added later.

By May 2007, over two-thirds of the Gotthard base tunnel had been excavated and the scheduled opening is in 2015.