Switzerland and 400 UHC® HSH®: Customer benefits by improving material design

Colleagues Julian Wiedorn and Oliver Fuchs from voestalpine Rail Technology, a company of voestalpine Railway Systems Group, explain how the geographical typography of Switzerland has challenged the manufacturer to develop the 400 UHC® HSH® rail grade, offering a solution to the problems of rail deterioration caused by high loads within Switzerland and further afield.

Challenging Switzerland

Switzerland’s unique and beautiful landscape of many lakes and mountains poses a considerable challenge for rail transport. Cities that are spaced far apart, as well as local neighbours, all have to be connected with each other, over long as well as shorter distances. For the railway and its infrastructure, especially for construction and operation, this means different geological conditions, tight curves and high gradients.
From a rail point of view, and also for the customer-oriented rail manufacturer, the last two points are particular important requirements: Tight curves and high gradients are known to cause high loads that are responsible for rail deterioration. To counteract this problem and, above all, these loads, voestalpine Rail Technology has developed the 400 UHC® HSH®.

Railways in Switzerland

The railway in Switzerland that connects most of the cities with one another is operated by the Swiss Federal Railway (SBB). Rural areas, but also special sections in urban areas, are supplied by railways who are part of the Association of Public Transport (VöV). More than 50 VöV railways exist in Switzerland. The geographical location explains the large number of different railways. At the same time, it defines important properties of these railways: many of their tracks are almost exclusively run in mountainous areas. Besides the typical narrow track gauge (1m instead of standard gauge 1.4m), curve radii smaller than 150m and inclinations higher than 20‰ increase the load on the infrastructure. With axle loads and speeds known from mixed traffic, sharp curves are now operated – radii that are more common in tram networks. This causes high wear and corrugation.

The results are low service lives, as well as increased noise and vibration. The latter is particularly unpleasant for people living close to rail lines, but also damaging for the remaining superstructure. The decisive factor here is the maintenance of the (optimum) new condition of the rail profiles. Besides, wear and corrugation problems concerning running behaviour will occur, which will influence the entire railway system.