In Switzerland, a crazy plan appears to be being hatched. Swiss engineers are working on an amazing public transport solution - an underground train taken to almost ridiculous extremes. Too fast to serve within a city, the Swissmetro¹ project involves running an underground train between cities around 50km apart. In itself, that isn't so amazing, but when it is considered that the technology used could result in journey times of just twelve minutes between Lausanne and Geneva, which would take up to an hour in a car, you start to realise just how amazing this could be. The Swissmetro website suggests that the system will be capable of achieving passenger service speeds of over 500 km/h in 'total safety'.

So how does it work, then?

The proposal involves a strange mix of technology. The train would use a Maglev² (Magnetic Levitation) system and would 'float' 20mm above the track - which of course avoids a huge amount of tedious friction. This is a development of the same technology that powered the somewhat less ambitious, and unreliable, Maglev link between Birmingham International Airport and the adjoining railway station³.

The tunnel itself would be under a partial vacuum, reducing air pressure to reduce air resistance, allowing for much higher speeds to be achieved. This in turn requires that aircraft technology is used to pressurise the carriages of the trains, which in the 3D-rendered views released by the project appear almost exactly like an airliner interior.

The trains would have a capacity of around 400 passengers each, and the Swissmetro site describes them rather appealingly as 'both wheel-less trains and wingless aeroplanes at the same time'.

Environmental Advantages

Beyond the passenger capacity of up to 200,000 passengers per route per day, the ability to run services as often as every four minutes and the ability to have centrally located stations, the system is very clean. Assuming a good rate of seat occupancy, the Swissmetro uses half the energy of a conventional intercity train in operation, and less than a sixth of the energy per passenger involved in car travel.

Of course, with the speeds involved, the system would be a viable and indeed preferable alternative to short and medium-haul flights, which generate a lot of pollution and of course involve the risk of putting a lot of fuel and metal a long way up in the sky.

Cost

This is where the system is likely to see its biggest drawback. The planned Eurometro high-speed route serving Lyons, Geneva, Lausanne, Bern, Lucerne, Zurich, St. Gallen, Munich, Salzburg, Linz and Vienna would cost an estimated €40,000,000,000, equivalent to around £27,500,000,000, to build. This sounds an incredible amount, but when it is considered that the line would cut travel times from Lyons to Vienna from around 15 hours to just 210 minutes, the business and tourist implications are enormous. However, the developers envisage that they should be able to cover much of the development costs and all of the running costs with fares directly comparable to existing high-speed trains.

Safety

The thought of travelling so fast underground could seem quite daunting and even unsafe. Swissmetro envisage that the system will be at least as safe as current methods of travel for many reasons:

• The use of two seperate tunnels, one for each direction, as is the case with the Channel Tunnel, will make collisions close to impossible.
• The system will run one kind of service, at one speed - no hazardous goods or slow trains will impede the safety or efficiency of the service.
• The guidance system should prevent derailments.
• The weather will not affect the controlled environment within the tunnels.
• The use of fireproof materials and the low oxygen concentration in the tunnels will greatly reduce the risk of fire.

The system could have its first routes operating by 2020 and could be considered as a viable alternative to increasing air congestion across Europe, and with European investment, perhaps even Britain could operate an Edinburgh-London route, which could see the journey time reduced from a miserable day on the train to just a few hours.

In the meantime, there's an overground system running to and from Shanghai Airport - see TransRapid for more information.