DYNAMICALLY loaded bearings on which the load alternates or rotates in direction and on which the load intensity is constant or varies are discussed here. Practical bearing engineering, the authors say, has neglected this type although it represents the most important bearings in aircraft and automotive engines.The relative load-carrying capacity of a finite-length bearing is shown by the authors to be proportional to the expression: (2 load rpm - journal rpm).The test setup used to prove the formula is described by the authors. Oscillograph records are presented which show the change in oil film thickness as the load conditions are varied. The effect of running out of oil, on oil film thickness is demonstrated by the authors to be identical to approaching the critical value of zero load-carrying capacity as defined by the expression in the previous paragraph.A method for investigating the capacity of engine bearings is also discussed by them. They show that the value for a connecting-rod bearing varies from zero to ten times the load which a turbine-type bearing will stand.