ATSB issues Marine Occurrence Investigation report
The ATSB has issued the final marine investigation report on theunintentional release of thefreefall lifeboat from Aquarosa.
On 1 March 2014, Aquarosa was transiting the Indian Ocean en route to Fremantle, Western Australia, when its freefall lifeboat was inadvertently released during a routine inspection. A ships engineer, the only person in the lifeboat at the time, was seriously injured in the accident.
About 5 hours after its release, the ships crew recovered the lifeboat and resumed the voyage. On 8 March, the ship berthed in Kwinana, near Fremantle, and the injured engineer was transferred to hospital.
The ATSB found that when the lifeboat on-load release was last operated before the accident, it was not correctly reset. Consequently, when the engineer operated the manual release pump to inspect the equipment, the incorrectly-reset release tripped unexpectedly. The simulation wires, designed to hold the lifeboat during a simulated release, failed and the lifeboat launched.
The investigation found that although there was an indicator to show that the hook was in the correct position, there was nothing to indicate that the tripping mechanism was correctly reset. It was also found that the design and approval process for the lifeboats simulated release system had not taken into account effects of shock loading on the simulation wires.
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Contributing factors
- When the on-load release was last reset before the accident, it was not noticed that the release segment had not properly reset.
- While the design of the on-load release system allowed the reset position of the hook to be visually confirmed, it did not allow for visual confirmation that the release segment and mechanism had been correctly reset. Consequently, the hook device could appear to be properly reset when it was not. [Safety issue]
- An equivalent, alternative arrangement to the safety pin had not been provided to prevent inadvertent tripping of the freefall lifeboats on-load release during routine operations, such as inspections and maintenance. [Safety issue]
- All the risks had not been fully considered before the on-load release system hydraulic activation pump was operated to check for leaks.
- The simulation wires fitted at the time of accident were longer than required and had not been installed as per the manufacturers design guidance. Therefore, once the on-load release was tripped, the lifeboat travelled significantly further than it was designed to during a simulated release with a proportional increase in the shock load placed on the wires.
- The manufacturers calculations did not take into account the shock load imposed on the simulation wires or the lifeboat and launching frame mounting points. [Safety Issue]
- The Recognized Organizations process for the approval of the simulation wires for maintenance and testing had not taken into account the shock loading that would be experienced during testing. [Safety Issue]
Other findings
- The manufacturers documents contained inconsistencies in relation to the specifications of both the lifeboat and the simulation wires.
- There was no guidance in the manufacturers documents or in the ships planned maintenance system for simulation wire maintenance or replacement.
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You may read the report by clicking on the image below:
Source and Image Credit: ATSB
