Causes
The National Transportation Safety Board determined the following probable causes of the accident:
- the pilot’s degraded cognitive performance from his use of prescription medications, despite his completely clean post accident drug test,
- the absence of a comprehensive pre-departure master/pilot exchange and a lack of effective communication between Pilot John Cota and Master Mao Cai Sun during the accident voyage, and
- (Cosco Busan Master) Sun's ineffective oversight of Cota's piloting performance and the vessel’s progress.
Other contributing factors included:
- the failure of Fleet Management Ltd. to train Cosco Busan crewmembers (which led to such acts of gross negligence as the bow lookout eating breakfast in the galley instead of being on watch) and Fleet Management's failure to ensure that the crew understood and complied with the company’s safety management system;
- the failure of Caltrans to maintain foghorns on the bridge which were silent despite the heavy fog;
- the failure of Vessel Traffic Safety (VTS) to alert Cota and Sun that they were headed for the tower. VTS is legally required to alert a vessel if an accident appears imminent, yet they remained silent;
- the malfunctioning radar on Cosco Busan, which led Captains Cota and Sun to use an electronic chart for the rest of the voyage. Although Coast Guard investigators found the radar to be in working order, they did not examine it until days after the accident (allowing time for faulty equipment to be fixed, which is not uncommon after a marine accident)
- Captain Sun's incorrect identification of symbols on the electronic chart;
- the U.S. Coast Guard’s failure to provide adequate medical oversight of Cota, in view of the medical and medication information he had reported to the Coast Guard.
In addition, investigations conducted by independent experts from the international maritime community also highlighted the potential effects of insufficient Human-machine interface design, contributing to such accidents even though "human error" is often directly used as the main cause without further investigating shortcomings in the HMI. This is, even though HMI has been accepted as a significant factor in aviation accidents for many decades:
| “ | Lack of investigation of accidents at sea and the rash classification of the causes in the category of "human error" will help to cover weaknesses in the design of man-machine- interfaces. This is supported by legal regulations for the Bridge Team Management, the high investment cost for ship handling simulators, the low contribution of human-oriented research and its public support, as well as the readiness of manufacturers to develop more integrated and reliable process control systems. Although an inappropriate behaviour of the parties involved in the accident can be proved by the investigation report, the true causes of such accident like the container ship "Cosco Busan" stay in the darkness or in the field of speculation! The faulty design of man-machine-interfaces and deficiencies in information processing and others remain largely unmentioned. Based on a careful analysis of the accident documents the author proves that technical weaknesses were overlooked as well as failures in displaying and processing of information had not been taken into account. For the developers of new support systems and the aimed level of "dependability" of integrated ship bridge systems this is a great disadvantage. | ” |
Read more about this topic: Cosco Busan Oil Spill