Gravel flight

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Additional wind deflector (marked in red) on the ICE 3MF in the area of ​​the bogie to protect against flying gravel
Side window of a TGV damaged by flying gravel
Bonded (dark gray) and loose gravel (light gray)

As Ballast in is rail transport , the high vertebrae of ballast stones from the roadbed called. Flight of gravel is caused by the suction effect that occurs on the underbody of rail vehicles at high speeds or when detached ice masses hit the gravel bed. Unprotected components of rail vehicles can be damaged if the ballast stones are hit. To protect endangered parts, these are built into housings, for example, or provided with smoke deflectors and impact protection coatings.

Flight of gravel occurs only at speeds over 200 km / h . It is favored by high bulk gravel and small grain sizes . Flying gravel can be avoided by:

  • Reduce the driving speed
  • Compacting and lowering of the ballast under the sleeper level ( "Deep Return") and collecting exposed stones
  • Gluing the upper layers of gravel with special adhesives
  • Conversion of the ballast bed into a firm track

The effect was observed in 2003 during several test drives of the ICE 3M in France and Belgium, and the causes were determined in detailed studies. The phenomenon did not occur in Germany even at very high speeds, such as the ICE world record run on May 1, 1988 (406.9 km / h), as the Deutsche Bahn lowered the gravel below the threshold.

As a result of the onset of winter in France, several class 407 multiple units were severely damaged by gravel flight on the high-speed line between Paris and Strasbourg from 23 January 2019 . At times, 10 out of 17 multiple units were no longer operational.

Individual evidence

  1. ↑ Institute for Aerodynamics and Flow Technology: Gravel flight and subsurface currents , accessed on January 15, 2016
  2. ↑ DB Vertrieb GmbH: Announced onset of winter ( memento of the original from January 14, 2016 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. , accessed January 15, 2016 @1@ 2Template: Webachiv / IABot / www.bahn.de
  3. ↑ Die Welt from December 15, 2013: Protection against flying gravel , accessed on January 15, 2016
  4. ↑ Christoph Müller: ICE 3: Now also in France . In: Der Eisenbahningenieur , Volume 56 (2005), Issue 11, pp. 82–84.
  5. ↑ a b Rockfall from below . Spiegel online from September 5, 2015, accessed on January 15, 2016.
  6. ↑ Stony path . In: regional traffic . tape 23 , no. 2 , March 2020, ISSN  1615-7281 , p. 48-52 .
  7. ^ Frank Panier: Approval of the ICE 3 in France - the practical testing . In: Eisenbahn-Revue International , issue 11/2005, pp. 514-517.
  8. ↑ Gravel flight in France damages ICE trains . In: Eisenbahn-Revue International . No. 3 , March 2019, ISSN  1421-2811 , p. 156 .