Abstract
Machinery in ships is normally checked by inspection, under open conditions, periodically. Recently however, the intention to operate by condition monitoring, but without open-up inspection, is being considered. Under a circumstance of the ISO standards for condition monitoring procedures. ISO have issued the certification procedure for technicians, concerning the vibration monitoring started in some countries, in accordance with ISO18436. Nippon Kaiji Kyokai has investigated optimum condition monitoring methods for the diesel engine, especially for the main bearings. Some successful evidence is showing the effectiveness of high frequency vibration monitoring, and lubricating oil monitoring. This is a result of field testing: using large main diesel engines, and with the cooperation of engine manufacturers, shipyards and ship-owners. Some effective monitoring methods for plane bearing will be explained with the results of the authors' investigation.
