Ship containers not stowed correctly: ATSB
Shipping containers on a cargo vessel weren't stowed correctly before more than 80 toppled off the ship in rough seas off Newcastle in NSW, a report has found.
The Australian Transport Safety Bureau on Thursday said the loss of 81 containers from the YM Efficiency in mid-2018 highlighted the importance of safe and effective container stowage.
The YM Efficiency - a 43,000-tonne Liberian-registered ship - was travelling from Taiwan to Sydney when it was hit by huge seas off the coast of Port Stephens in June 2018.
The ship rolled heavily in the rough seas causing the container stacks to collapse with 81 containers lost overboard and a further 62 damaged.
The safety bureau - in its final report into the incident released on Thursday - found the force generated during the rolling placed excessive stress on the containers which led to them topple overboard.
The national transport safety investigator stated there was insufficient evidence, however, to establish why the ship suddenly rolled to such a degree in the first place.
The bureau found the weight and distribution of the containers meant the "calculated forces exceeded allowable force limits" as set out in the ship's cargo securing manual.
The ATSB also found the stowage arrangements on the YM Efficiency were not checked for compliance during the planning process onshore.
"This left sole responsibility for compliance with the ship's officers, with limited options to resolve deficiencies at a late stage in the process without unduly impacting operations," ATSB chief commissioner Greg Hood said in a statement.
"Safe and effective container stowage planning is the primary control measure in managing the risks involved in carrying containers by sea."
In the months after the incident, substantial debris from the lost containers washed ashore along the NSW coast. Fishing trawlers hooked-up on containers or other lost material.
The ATSB said at the end of its investigation 66 containers had been located with a few washed ashore or close to shore and five removed. Fifteen containers are yet to be found.
The shipping company, Yang Ming, has since implemented regular checks of the ship's lashing forces and regular staff training on cargo loading and securing.
"The ATSB considers that the safety actions taken by Yang Ming have adequately addressed the issues that our investigation identified," Mr Hood said.