THE AUSTRALIAN Transport Safety Bureau (ATSB) has released its findings on two separate incidents of container ship breakaways while berthed at the Port of Brisbane.

The breakaways involved vessels OOCL Brisbane and CMA CGM Bellini on 16 and 20 May 2022 respectively, after an unprecedented stretch of rainfall resulted in significant freshwater inflows into the Brisbane River following several controlled water releases from dams located upriver.

The ATSB says this resulted in strong currents through the Port of Brisbane at the mouth of the river, which added strain to the mooring lines holding ships berthed there.

On 16 May 2022, container ship OOCL Brisbane broke away from Fisherman Islands’ berth 10, operated by Patricks Autostrad, and four days later another container ship, CMA CGM Bellini, broke away from berth 6, which is operated by DP World.

“Fortunately, the ships were brought under control in both cases, and there were no injuries or substantial damage in either incident,” ATSB chief commissioner Angus Mitchell said, “but breakaways can have serious outcomes”.

The ATSB investigation found that both breakaways occurred due to the strong currents following the high rainfall combined with the interaction forces created when a second container ships passed alongside and then berthed ahead of each vessel.

“The high ebb current speeds and the interaction forces introduced by other vessels resulted in the mooring limits for both ships being exceeded,” Mr Mitchell said.

In the case of the OOCL Brisbane, all the ship’s mooring lines parted or paid out, and it moved into the Brisbane River before being assisted by tugs.

CMA CGM Bellini’s forward mooring lines parted, and its bow drifted off the wharf before it too was assisted by tugs to be secured alongside.

In the course of its investigation, the ATSB identified that Maritime Safety Queensland (MSQ), the regulator, and the Poseidon Sea Pilots (PSP), Brisbane’s pilotage provider, did not have a process to jointly and effectively identify the hazards to shipping and pilotage that were outside normal environmental conditions, and to properly assess the associated risks.

“These breakaways highlight the importance of robust, properly structured and clearly defined emergency and risk management arrangements for managing port shipping movements outside of normal operating conditions,” Mr Mitchell said.

“Such arrangements must facilitate accurate assessment of all the available information by the involved parties and provide for adequate assessment of all potential risks.”

Mr Mitchell recognised the safety actions taken by both MSQ and PSP in response to these incidents, as well as another breakaway, further upriver and a month prior, which was also investigated by the ATSB.

The ATSB said PSP and MSQ have collaborated with a range of stakeholders to improve extreme weather event planning and response, and to establish a formal channel to identify and risk assess hazards to shipping outside of normal environmental conditions.

This has included the establishment of the Port of Brisbane Maritime Emergency Working Group, with guidelines developed for the group’s role in responding to port emergencies.

Additionally, three additional current meters have been installed in the river, adding to the one installed prior to the incident, with additional meters planned. Data from these meters will reportedly be provided by MSQ to key stakeholders, including PSP.

PSP has provided input for changes to MSQ’s standard port procedures, including the joint development of procedures for movements to and from various berths under flood conditions, using MSQ’s bridge/ship simulator.