EURIF
NON-PROFIT ASSOCIATION OF ENGINEERS AND ARCHITECTS

ANTIFLYING BALLAST

 

Our new sleeper offers added performance in the field of ballast flight and track geometry stability over those already demonstrated by traditional sleepers, offering a global solution to the phenomenon and minimizing maintenance requirements:

- It is characterized by having on its upper part a surface constituted by two inclined planes in the form of a roof - instead of horizontal faces - to prevent ballast stones from being deposited on it and thus prevent them from being aerodynamically propelled as trains pass. In this way, the occurrence of the phenomenon is solved at source.

- In addition, the provision of a plastic sole as the lower support surface contributes to increasing the transverse resistance of the sleepers, thus offering a higher degree of stability of the track geometry, especially considering that another of the measures recommended to avoid the phenomenon of ballast flying is to keep the upper face of the ballast bed a few centimeters below the level of the upper face of the sleeper.

- The optimization of other components - such as fastenings - contributes to an advanced and integral solution for use on new high-speed lines, especially for values of this even higher than the usual 300-350 km/h.

Why a new sleeper?

In the early 2000s, the widespread success of the operation of the first high-speed lines led several operators to gradually increase the running speed in order to increase the efficiency of the system by offering a more attractive service.

In some test runs, a new phenomenon became apparent, namely the high-speed projection of ballast stones as trains passed in the 300 km/h range. The damage caused to the rolling stock and the environment of the line justified the interest in identifying the cause of this aerodynamic event - known as “ballast flying” - in order to solve it. 

 

That is why numerous institutions worldwide have been interested in how to solve these problems, as in the United States, the Federal Railroad Administration (FRA) agency under the Department of Transportation (DOT) of the federal government and highest railway authority has published a document which includes requirements to be taken into account to avoid the risk of ballast flying on new high-speed lines.

The use of our innovative sleeper on new high-speed lines makes it possible to operate them at speeds above 300-350 km/h under desirable safety conditions without increasing maintenance costs, as shown by scientific studies and tests on different high-speed networks, thus solving the problems previously mentioned.