Flat track

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The title of this article is ambiguous. For the Berlin tram line called Flachbahn , see Flachbahn (Berlin) .

With flat track level are railway lines referred to the course of which only a small extent to the local conditions and the topography adapts and therefore not a big gap has and, if it is a high-speed line is, no tight curve radii . This enables these routes to be used for all possible types of train . In the case of heavy freight trains, there is no need to use additional locomotives to cope with inclines.

The construction of flat railways is expensive and time-consuming, as numerous engineering structures such as bridges , tunnels , cuttings or dams have to be built in order to ensure that the lines are as straight and balanced as possible. Values ​​between 10 and 12.5 ‰ ( Germany ) are given as the upper limit for the permissible incline of flat runs . The model of the flat railway for mixed passenger and freight traffic is controversial because of the high construction costs and (as a result of large speed differences) the relatively poor use of capacity. Since passenger trains in general and high-speed trains in particular have powerful engines, they cannot benefit from the flat layout of a route.

In Switzerland, the term flat railway is often mentioned in connection with the construction of the new base tunnels through the Gotthard and Lötschberg , although the Lötschberg-Simplon axis does not meet the definition criterion mentioned above. On the Gotthard axis is the apex of the old Gotthard line at 1150  m above sea level. M. , that of the base tunnel is 600 meters lower at only 449  m above sea level. M. located, which only corresponds to the sea ​​level of the federal city of Bern located in the midland . However, in order to consistently implement the principle of the flat railway between Basel and Chiasso, after the opening of the Ceneri base tunnel at the end of 2020, the southern connection between Lugano and Chiasso must be built; a still outstanding project worth billions, which illustrates the problem of implementing a flat runway in the alpine region. The Mont-Cenis (Lyon-Turin) and Brenner transit axes are also to be converted into flat railways by building base tunnels. In the latter case, however, as with the Gotthard, this goal will only be fully achieved with the construction of a new south access.