ABSTRACT
This investigation highlights the safety of DP (Dynamic Positioning) systems by briefly discussing the existing risk assessment methods and risk control measures provided by the International Maritime Organization (IMO). Following a study regarding DP systems and the loss of position incidents reported to the International Marine Contractors Association (IMCA) and contained in the World Offshore Accident Databank (WOAD), the relevant hazards are identified and collated. The primary causes of loss of position incidents were found to be: the positional reference system failures and thruster failures, with both contributing to 20.6% each of the total incidents from 2000 to 2016. Similarly the time period of the analysis is the 17 years between 2000 and 2016. Given the two stated primary causes, the positional reference system failures and thruster failures, the thruster failures are analysed further. This is due to thruster failures occurring at an increased rate within DP incidents from 2011 to 2016. Hence, this trend, between 2011 and 2016, is analysed further. Three undesired events for loss of position due to thruster failures were identified, these are as follows: “drive off”, “drift off” and “time loss”. Further investigation of incidents in more recent years, in this case, 2012 to 2016, identified that the DP control system accounted for 33.7% of the initiating incidents that led to thruster failures. Furthermore, the undesired event “time loss” accounted for 71.2% of total incidents caused by thruster failures.
