This report is a Master Thesis, which has been made in order to test and verify a new proposed standard on how to design railway vehicles in aspect to its exterior size. The newly proposed standard is called alternative gauging. The project has been done for Bombardier Transportation and The Swedish National Rail Administration (Banverket).

Rail vehicles exterior size has to be adapted so that the vehicles never interfere with obstacles of the infrastructure and other vehicles on adjacent tracks. This could be done by allowing large clearances by designing slim vehicles but this does not make efficient use of the available space. The clearances between vehicles and obstacles must allow for movements of the vehicle in particular due to vertical and lateral movements in the suspension. The process of exterior sizing in Sweden has up to now (2004) mainly been based on conservative geometric considerations assuming that movements are the largest possible to suspension stops etc. By tackling the process differently it should be possible for the vehicles to use the available space given by the infrastructure more efficiently. The newly proposed standard uses more realistic assumptions and it is based on two methods for calculating movements. The first one is based on dynamic simulations and the second one on geometrical formulas. These two methods need to be verified in order to prove their suitability and validity. Verification and further development of the new gauging procedure is the purpose of this thesis.

This study has been done with two types of vehicles of very different types: Regina, a regional high-speed train and Laaips962, a two-axle freight wagon. The resulting movements given by formulas and simulations have been compared with a reference contour, in this case a so-called dynamic envelope, which shall include the vehicle and all its movements.

A comparison between the results from formulas and simulations has been made. It was desired that vehicle movements from formulas should be a bit more conservative in the sense that they would give slightly larger movements. Using the original formulas and procedures in this investigation, this requirement is not always fulfilled. Therefore a few slight modifications to the original formulas have been proposed. Furthermore, in order to receive smaller and more realistic simulated movements the cant irregularities should be scaled to what maximum allowed is according to BVF 587.02 instead of being scaled with the same factor as for the vertical irregularities. Also, in order to avoid exaggerated simulated movements, it is recommended to calculate the movements of an evaluation point in relation to an average dynamic envelope determined from the track position from -5 m to +5 m from the evaluation point to avoid that very local irregularities shift the reference contour. Finally, calculation of vertical movements, including suspension, and wheel wear, should be further developed and clarified.

Most important of all is that the proposed standard is useful and reliable in all cases tested in this study.