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In order to calculate, simulate, and optimize the energy demand of train runs, the running resistances have to be modeled. Mostly, simplified - e.g. the Davis equation - or approximated formulas for part resistances are used. This also applies for the aerial resistance: for cw value, effective surface area, air density, and relative air speed, either approximate or norm values are used in general. Contrariwise, aerodynamic investigations show that the aerial resistance does not decay with the cosine of the increasing yaw angle as the use of relative air speed indicates; in contrast, the aerial resistance increases up to a yaw angle of 60°. In this paper, a numerical model including this phenomenon is presented; moreover, wheel flange contact occurrence as consequence of side wind forces is discussed. The presented case studies confirm that the wind and its yaw angle may have a relevant influence on the energy demand. [ABSTRACT FROM AUTHOR]

The BOMBARDIER FLEXX Urban 3000 bogie platform is used for 100 % low-floor trams. Its characteristics are low noise, high comfort, robustness, reliability and high level of safety. The FLEXX Urban 3000 bogie platform includes various configurations, which have been described in this paper in 2013. It has now reached the next steps in his development, which are described in this article. FLEXX® is a registered trademark of Bombardier and includes eight Platforms from FLEXX Urban for city traffic until FLEXX Power for Locomotives or FLEXX Speed for High speed trains. More than 200 000 FLEXX® bogies are in service in 44 countries all over the world. [ABSTRACT FROM AUTHOR]

As announced at the last Congress in Graz, in the group wide project “Identification of the wear reduction potential of the ÖBB-fleet locomotives" some prototypes have been tested for one year and the measured data was analysed. In this paper the vehicle based measures like the special bogie equipment, the monitoring of the wheel wear and the accomplished test runs for investigation of the traction force are presented. Additionally the infrastructural measures like building the specific measuring site in Schwechat, the monitoring of the dynamic forces and the test runs over other measuring sites are introduced. [ABSTRACT FROM AUTHOR]

Bogies with independently rotating wheels (IRW) seem to be only a compromise because of missing space for an axle. In this paper the theory of track guiding by IRW is explained and it is shown that IRW had some advantages over wheelsets if there are used in narrow tram networks. Those cbnsiderations are proved by field data. It is obvious that tramcars with IRW are characterized with best comfort and less wear - if the particu­larities of that principle are respected. [ABSTRACT FROM AUTHOR]