Concerns have arisen regarding the dangers of a hydraulic ram not being properly reset after use in Chinese-made JX-4 release mechanisms from Jiangsu Jiaoyan Marine Equipment Company after a freefall lifeboat launched during a maintenance inspection seriously injuring the occupant. Simulations wires which should have restrained the lifeboat and prevented the launch also failed below their safe working load and are being investigated.
The issue has come to light in a preliminary report by Australia’s Transport Safety Board on the inadvertent launch of a lifeboat from the gearedbulk carrier Aquarosa in March this year.
In Singapore, 5 days before the incident, the second engineer was involved with multiple checks of the lifeboat release hook operation. During these checks, he noticed that the hydraulic system was low on oil and he topped it up. He also noted that the activation of the hook release required between 10 and 15 operations of the hydraulic pump handle.
On 1 March 2014, with this knowledge in mind, the second engineer entered the lifeboat to satisfy himself that all was in readiness for any possible upcoming port state inspection. He noted the oil level was low in the release pump and topped it up. He then pressurised the system to see if he could locate any leaks. He operated the pump 3 or 4 times, well short of the 10 to 15 pumps he believed it normally took to release the hook, but the hook unexpectedly released.
Inspection of the lifeboat, its release mechanism and analysis of the available evidence showed that the actuating cylinder ram did not always retract fully into the cylinder without some external force being applied. Furthermore, it was found that the hook stopper block could be repositioned sufficiently to engage the hook and prevent it opening without the actuating cylinder ram being fully retracted. In such cases, with the hook reset, the hydraulic pump recirculation valve could be closed trapping the system in this position.
It is likely that this is what happened when the lifeboat release system was reset following the tests in Singapore. Then, on 1 March, the second engineer only had to operate the pump handle three or four times for the actuating cylinder ram to move far enough to release the stopper block and the hook.
In such circumstances, the release hook could be activated with a reduced number of operations of the hydraulic pump because the actuating cylinder ram had less distance to travel before it released the stopper block and the hook.
Following the incident, a safety pin that can be placed into the release hook when entering the boat for inspections and maintenance has been made up on the Aquarosa. Tool box meetings are now required before entry into the lifeboat to carry out maintenance and procedures which list the checks that are to be made prior to any lifeboat maintenance being carried out have been implemented. Further, the master’s permission is now required before the lifeboat release system hand pumps are operated. Warning signs have been placed at the pump locations stating this requirement.
. Tool box meetings are now required before entry into the lifeboat to carry out maintenance and procedures which list the checks that are to be made prior to any lifeboat maintenance being carried out have been implemented. Further, the master’s permission is now required before the lifeboat release system hand pumps are operated. Warning signs have been placed at the pump locations stating this requirement.
Recently, members of the LinkedIn Maritime Accident Investigation group have expressed concerns about lifeboats and equipment manufactured in China. Says one member: “I have had experience with a bonafide internationally manufactured major lifeboat company whose field repair shop was in Shanghai and it was worse than I could possibly describe.
I would never recommend a hook retrofit in China, even if the hooks were made in the USA or purchase a Chinese lifeboat. “
In a survey of seafarers by Maritime Accident Casebook freefall lifeboats account of about a quarter of incidents and close-calls involving lifebats.