Researchers: Thomas Nordmark (PhD candidate), Jan Lundberg (PL)
Goal: To deliver and understand the dependence between maintenance costs and axial load for heavy loaded cargo trains.
Project status and results: LKAB uses IORE electrical locomotives to haul their heavy haul trains. During a period of 5 years from 2006, the wheel life started to decrease because of increased rolling contact fatigue (RCF), dropping to around a third of its original life length. During this time period there were a lot of operational changes which included; introduction of new ore wagons, longer and heavier trains, increase of axle load on both the locomotives and wagons from 25 to 30 tonnes and an upgrade of the infrastructure. A series of actions were undertaken by LKAB from 2009 to 2017 to try to restore the wheel life length. These actions included field tests with a revised wheel profile, a new improved wheel steel grade and a combination of revised profile and improved steel grade, limitation of electro dynamic braking and lowering the axle load. The project has presented and analysed the results from the different actions tested in the field on the iron ore line Malmbanan. The most
important finding is that an improved steel grade will not give any benefit if not the wheel profile is optimised first. The present wheel life length has increased from 250 000 to 595 000 km for locomotives with revised wheel profile and an improved steel grade.