High-speed rail in Europe
Switzerland has no high-speed trains of its own yet. French TGV (TGV Lyria) and German ICE lines extend into Switzerland, but given the dense rail traffic, short distances between Swiss cities (because of the country's small size) and the often difficult terrain, they do not attain speeds higher than 200 km/h (ICE3) or 160 km/h (TGV, ICE1, ICE2). The fastest Swiss trains are the ICN tilting trains, operated by the Swiss Federal Railways since May 2000. They can reach higher speeds than conventional trains on the curve-intensive Swiss network, however the top speed of 200 km/h can only be reached on high-speed lines. The former Cisalpino consortium owned by the Swiss Federal Railways and Trenitalia used Pendolino tilting trains on two of its international lines. These trains are now operated by the Swiss Federal Railways and Trenitalia.
Development of the TGV
The TGV (, high-speed train) is France's high-speed rail service. The idea of a high-speed train in France was born about twenty years before the first TGVs entered service. At that time, about 1960, a radical new concept was thought up; combining very high speeds and steep grades would allow a railway to follow the contours of existing terrain, like a gentle roller coaster. Instead of one or two percent grades which would be considered steep in normal applications, grades up to four percent would be feasible, thus allowing more flexible (and cheaper) routing of new lines. Over the next several years, this very general idea gave rise to a variety of high speed transportation concepts, which tended to move away from conventional "wheel on rail" vehicles. Indeed, the French government at the time favoured more "modern" air-cushioned or maglev trains, such as Bertin's Aérotrain; Steel wheel on rail was considered a dead-end technology. Simultaneously, SNCF (the French national railways) was trying to raise the speeds of conventional trains into the range 180 to 200 km/h (110 to 125 mph) for non-electrified sections, by using gas turbines for propulsion. Energy was reasonably cheap in those years, and gas turbines (originally designed for helicopters) were a compact and efficient way to fulfil requirements for more power. Following on the TGS prototype in 1967, SNCF introduced gas turbine propulsion with the ETG (Elément à Turbine à Gaz, or Gas Turbine Unit) turbotrains in Paris - Cherbourg service, in March 1970.