Abstract: In order to monitor the function of the sliding block bearing elements in view of the hydrostatically and/or hydrodynamically generated compressed oil film or, respectively, compressed oil cushion, given rotating drums seated on sliding blocks such as, for example, tube mills, and to control the operation in conformity with the result of the monitoring, it is inventively proposed that the lubricating gap thickness, i.e., the distance between the bearing surface of the sliding bearing shoe and the running surface of the rotating drum supported thereon via the lubricating gap or, respectively, the compressed oil film, is directly measured during operation and the rotating drum operation is controlled dependent on this measured quantity.