The Australian Transport Safety Bureau has released its preliminary report on the loss of containers overboard container ship YM Efficiency, off Newcastle on June 1.
The Yang Ming Marine Transport-operated container ship lost 81 containers overboard in gale-force weather conditions.
The occurrence also resulted in damage to a further 62 containers and structural damage to the ship's gangway, superstructure and lashing bridges. The ship was on a regular service, calling at ports in China, Taiwan and Australia.
The ATSB say the ship experienced a period of quick, heavy rolling for about 60 to 90 seconds. The rolling was estimated by the ship's master as having reached angles of up to 30º to port and starboard. Shortly after the start of the rolling, several engineering alarms sounded and the main engine shut down with the rpm reducing to zero.
Within two minutes, the rolling had reduced and the ship's motion had calmed.
The master took over the navigation of the vessel and instructed the chief officer to conduct a damage assessment, he reported several containers damaged or lost overboard.
The ATSB's investigation is continuing.
YM Efficiency is a 268.8 metre-long, 4,250TEU container ship, owned by All Oceans Transportation. At the time of the incident, the ship was classed with the American Bureau of Shipping.