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.
Madrid–Seville high-speed rail line
Trains travel along the line at 300 km/h during the sections of the track close to Madrid. They travel at 200 km/h through the Sierra Morena region, possibly because the S/100 trains aren't pressure-sealed and this section includes many tunnels and also because of the tight curvatures in the Sierra Morena (occasionally dipping as low as 2300m). According to the HS2 website, a 200 km/h track needs a curvature of 1800m and a 400 km/h track needs a curvature of 7200m. As the necessary curvature increases in proportion to the square of the maximum velocity, the maximum safe speed for a curvature of 2300m would be 226 km/h, assuming no tilting technology: - only the AVE Class 100, AVE Class 102 and AVE Class 103 run through the Sierra Morena section, of which only the AVE Class 102 has tilting technology. The trains travel at a top speed of 250 km/h between Córdoba and Seville, possibly on account of the AVANT services that also use the line, whose trains are limited to 250 km/h. On most journeys, the trains spend a very small proportion of the journey travelling above 250 km/h, although most of the Málaga branch is done at 300 km/h (save for station approaches and the Gobantes and Abdalajís tunnels). The trains slow down to approximately 160 km/h when travelling through Ciudad Real station. They also have to slow down to 70 km/h when travelling through Puertollano station because of the lack of a bypass route and tight curvatures in the station.