Risk based maintenance of the three portal cranes at Bergen group Rosenberg yard

Abstract

The portal cranes at Bergen Group Rosenberg as been a major part of the success that the yard has achieved since the first two were built in 1960. The third one came 15 years later with a slight different structure and with a larger capacity. As these cranes grow older more thorough maintenance are needed, and for them to still have success they need to move away from corrective maintenance and towards new technology and condition monitoring. This thesis will focus on condition monitoring and to come with suggestions on improvements to the existing maintenance program with regards to risk based maintenance. This thesis concludes with that vibration monitoring and NDT should be implemented to the maintenance program. Keeping the fresh incident from last year in mind, where a nut of 3,1 kg loosened and fell down from the tension rod and hit the ground underneath the crane (45 meters drop). With vibration monitoring already in place this might have been prevented from happening. Even though it is expensive to implement these techniques this is something that Bergen Group Rosenberg will profit by over time, and will help keeping the good reputation that the company and the Yard has had for decades.