ERTMS - approximation av lutningar för högre kapacitet på järnvägsnätet

Sammanfattning: Ådalsbanan, an existing railway-line in northern Sweden, is a line that has been upgraded from the current Swedish signaling system, ATC, to the new standard in Europe, ERTMS. While the upgrade was ongoing there was a problem discovered, there were too many gradients on the line for the system to handle. This is because the system can’t handle more than 31 gradients on one movement authority, which can be up to 10000 meters long. The problem was solved by doing a temporary solution specially meant for Ådalsbanan. The solution was to merge gradients that were placed next to each other and within an interval of three per mille. Further on it has come to conclusion that this probably wouldn’t be efficient enough to be a nationally excepted solution, our mission has been to find such a solution. We have developed three different solutions which have been forwarded for review to different persons at the company that we are doing this thesis for, Vectura. The first solution was to do as in the solution for Ådalsbanan but with different intervals. The second solution was to divide the 10000 meters with the 31 allowed gradients and then start in the beginning of the line and merge gradients until they were at least 330 meters long together. The stretch was then approximated after the lowest gradient on it. The third solution was to approximate according to the average of a stretch where the gradients were within an interval of three per mille. Calculations were done to retrieve the impact on the average of the gradients on the line, number of gradients that were eliminated and which interval in solution one that should be chosen for different set of gradients. The solutions were developed with help of the feedback from the review. Solution number three was changed so that it would be more alike solution number two – the gradients are merged until they are over 330 meters and then approximation was done according to the average of that stretch. This solution was also chosen as our final solution since we feel that it has the biggest potential. However, we chose to have solution number one as a back-up solution in case that our final solution wouldn’t satisfy the high security demands. Further development of the thesis is finding out how safe the final solution really is.