Australia’s Transport Safety Board has released its report into the lost of containers from the containership Pacific Adventurer, the subsequent holing of the hull and subsequent pollution.
The ATSB investigation found that the most plausible explanation for Pacific
Adventurer’s severe, and at times violent, rolling motions was synchronous rolling, as a result of the ship’s natural roll period matching that of the encounter period of the waves experienced.
While the master took action to avoid the rolling, in accordance with the guidance in the ship’s safety management system, this action was not sufficient. The option of altering the ship’s stability by adjusting the seawater ballast in its tanks, and therefore its natural roll period, as the ship made its way up the Queensland coast, was not considered.
Much of the ship’s fixed and loose lashing equipment was in a poor condition.
While this had been recognised by senior officers on board, and shore management, the progressive replacement of the equipment had not progressed to the Bay 25 area. In addition, because not all the stacks of containers in Bay 25 were lashed, there was different flexibility in adjacent stacks. It is likely that the unlashed stacks of containers imposed excessive forces on neighbouring lashed container stacks which caused the lashings and the containers to fail when subjected to the significant forces resulting from the ship’s excessive roll motions.
The investigation also identified that the ammonium nitrate prills were packed in the containers in such a way that if a wooden bulkhead at the after end of a container gave way, the weight of the cargo could have resulted in a failure of the container’s end-wall. This could have contributed to the failure of the containers and/or the lashing system.
The ATSB identified the following safety issues during the investigation:
• The poor condition of much of the ship’s container lashing equipment indicates that the inspection and maintenance regime applied to this critical equipment had been inadequate.
• At the time of the incident, there was no requirement for any third party to inspect or survey the fixed and loose lashing equipment on a ship.
• The ammonium nitrate prills were not packaged in the containers in accordance with the requirements of the International Maritime Dangerous Goods Code.
• The Australian Maritime Safety Authority’s International Maritime Dangerous Goods Code compliance audit regime had not detected that the method of packaging was not compliant.
Safety action to address the safety issues was taken by several of the responsible agencies. The ATSB has issued one safety advisory notice in regard to the outstanding safety issue concerning third party inspections of lashing equipment.