Describes a comprehensive field test to determine the best grease for spherical roller bearings in railway waggon wheels and increase the knowledge of grease lubrication. Nine different fully-formulated commercial greases were examined in the wheel bearings of five ore waggons, used for transporting ore commercially by railroad from the Kiruna Mine in northern Sweden to Narvik in northern Norway for shipping to foreign markets. After the end of the test period, the wear and electrical damage, as well as the rust on the bearings, were also studied. In order to find out the optimum grease for this application, draws up a specification of requirements and uses a systematic approach to development of an evaluation method that could be applied to greases in actual service.