Wind-Induced Tip-Over

An operational safety issue facing railroad operators is wind induced tip-over. Multiple studies were completed using CFD to develop a database of tip-over tendencies for a variety of car types within various railway fleet. The use of this database in the development of a speed restricting system for the Sandusky Bay Bridge is also discussed.

Train Accident

Freight Train Derailment:
BNSF Bellemont AZ – 6 Oct 2010

High winds have caused a number of accidents involving freight trains. Select examples include:

  • 11 February 2003: Norfolk Southern Railway,
    Train derailed on Sandusky Bay Causeway in Sandusky, OH
  • 6 October 2010: Burlington Northern Santa Fe Railway,
    Two trains derailed due to high winds in Bellemont, AZ
  • 17 June 2013: Burlington Northern Santa Fe Railway,
    71 rail cars that were double-stacked with shipping containers derailed near Hereford, TX
  • 18 September 2013: Union Pacific Railroad,
    7 cars derailed near Chicago, IL
  • 13 March 2019: Burlington Northern Santa Fe Railway,
    26 cars derailed off a bridge near Logan, NM
  • 24 April 2019: Union Pacific Railroad,
    25 loaded tank cars detrailed, leaking 74,000 gallons of denatured ethanol in Fort Worth, TX
  • 18 August 2019: Burlington Northern Santa Fe Railway,
    Two trains derailed with over 100 rail car derailments near Walton, KS

Airflow Science's work includes:

Rail Car
  • Develop database of railcar rolling moment to predict impending tip-over conditions. Analysis included box cars, hopper cars, well cars, gondola cars, autorack, 53' trailer/flat cars.
    • Wind tunnel test data of CFD simulations
  • Supply relations to integrate aerodynamic database into a vehicle dynamics modeler's VAMPIRE simulations.
  • Develop real-time computer algorithm to alert train dispatch center of appropriate speed reductions in possible tip-over conditions.
  • Select and locate wind sensor and configure system to display appropriate speed restrictions.

Tipping Moment Data:

Wind Tunnel Graph

Wind tunnel tests
(16% and 30% Scale)

CFD of Train Car Tipping
CFD Legend

CFD models (example is 53' well car)

Results of Study:

A Speed Restricting System was developed which is installed alongside the tracks at the Sandusky Bridge. The system measures real-time wind conditions and communicates with dispatchers to provide immediate recommendations for safe speeds based on wind speed and direction for multiple car types.

Speed Limit

Allowed train speed chart

Speed Restricting

Speed Restricting System (SRS) screenshot


Azore CFD Software

Airflow Sciences Equipment