This paper presents the results of three failure investigations carried out by DNV Maritime Technical Advisory. The first case is the failure of an oil distribution shaft in the main propulsion shafting for on oil tanker. The second case is the failure of an azimuth thruster for a drilling rig. The third case is the fracture on a high speed intermediate shaft on a platform supply vessel.
Failures of propulsion machinery and components occur at all stages of a vessel's lifecycle and have often a serious impact on the maneuverability and safety of the vessel. In addition, machinery failures will also often cause expensive loss of hire and disrupt a vessel's schedule and operation. The environmental impact after an incident is another concern that is becoming increasingly important and subject to enquiries from regulatory agencies and other stakeholders.