While TT-Line Company’s standard mooring line pattern for ships at Station Pier had been successfully used for many years, the breakaway indicated the risk could have been further reduced to better prepare for such unusual circumstances.
The safety actions undertaken by TT-Line Company have reduced the likelihood of a company ship breaking away from the berth under similar and reasonably expected weather conditions.
Mooring arrangements
TT-Line advised the ATSB that it has commenced an in-depth review and analysis of berthing ships at Station Pier. This has included engaging external maritime consultants to conduct assessment, analysis and simulations of the mooring conditions and arrangements. The aim is to achieve recommendations on the optimal operating parameters including changes to berthing arrangements and infrastructure if necessary.
TT-Line also advised that the initial consultant’s mooring analysis report had verified the mathematical model used for computer simulations, which had confirmed the details and sequence of the incident. The ongoing analyses will define operational parameters and propose necessary changes to ship berthing arrangements and/or infrastructure.
In addition to these analyses, all mooring lines have been changed to the same type and specifications, with breaking load of 96 t.
Procedures
TT-Line has updated and expanded procedures in relation to weather preparations and responses at Station Pier. This includes advising ships’ crews that all mooring lines are to be held on the winch brake, not in self-tension
The procedural review is ongoing and changes are to continue based upon the outcomes of the mooring investigations.
Weather notification
TT-Line advised the ATSB that it has improved the ship and company procedures and reliability of weather and associated warning notification.
The ATSB acknowledges the proactive safety taken by TT-Line, which has partially addressed the safety issue. The ATSB considers that the company’s mooring analysis, when completed, and safety action as a result of that analysis have the potential to adequately address the issue. Therefore, the ATSB has issued the following recommendation.
The Australian Transport Safety Bureau recommends that TT-Line Company take necessary action to adequately address the safety issue following the completion of its mooring analysis.
TT-Line have advised the ATSB they have continued to assess and improve weather response actions for its ships berthed at Station Pier.
The external consultant's mooring system analysis report has been received by TT-Line and resulted in changes to:
These changes will reduce the likelihood of one of the company's ships breaking away from the berth under prevailing and reasonably expected weather conditions.
The company reports the updated protocols have been successfully enacted on several occasions, including during thunderstorm warnings.
TT-Line further advised they will continue to monitor and improve the effectiveness of mooring of its ships.
