16 FEB 2020
The Australian Transport Safety Bureau (ATSB) has released its final report from its investigation into the loss of containers from the container ship YM Efficiency, saying the loss of 81 containers overboard in very rough seas on July 1, 2018 highlights the importance of safe and effective container stowage planning.
Just after midnight on June 1, 2018, the YM Efficiency was steaming slowly into strong gale force winds and very rough seas off Newcastle, en route to Sydney, when it suddenly rolled heavily, causing container stacks to collapse and topple. As a result, 81 containers were lost overboard and a further 62 were damaged, while the ship sustained structural damage to its lashing bridges, superstructure and accommodation ladder.
Substantial debris from the lost containers subsequently washed ashore on the New South Wales coast. Search efforts have located only 66 containers of the containers, with a few having washed ashore or close to shore. Five containers have been removed, and 15 containers have yet to be found.
The ATSB investigation determined that the forces generated during the sudden, heavy rolling placed excessive stresses on containers stowed aft of the ship’s accommodation. This resulted in the structural failure of containers and components of the lashing system, leading to the loss of containers overboard.
All potential causes for the sudden rolling were investigated, such as the possibility of an abnormal wave, but there was insufficient evidence to establish a definitive cause.
The condition of the ship’s lashing equipment was considered not to have contributed to the loss of containers. However, the investigation found that the weights and distribution of containers in the affected bays were such that calculated forces exceeded allowable force limits as defined in the ship’s Cargo Securing Manual (CSM). The investigation also identified that the stowage arrangement was not checked for compliance with the CSM’s calculated lashing force limitations during the cargo planning process ashore.
ATSB Chief Commissioner Greg Hood said: “Checking stowage plans for compliance with the Cargo Securing Manual requirements is increasingly achieved through loading computer systems. Notwithstanding the efficiency of computerised loading systems, the scale and pace of modern container ship operations puts significant pressure on ship’s officers to check and amend or approve proposed stowage plans at a late stage.”
He noted that in that context, the planning process ashore offers the best opportunity to take all practical measures to ensure that the proposed stowage plan presented to ships officers complies with the CSM and is as safe as reasonably practicable.
The officers did not use the ship’s loading computer system and its lashing calculation program to check if the stowage arrangement complied, as they probably did not have an adequate understanding of the system.
The report is available here.