The Danish Maritime Accident Investigation Board (DMAIB) released its report about an unintended release of a rescue boat on 6 December 2017, in Norway. The accident happened as an annual survey of the ship, “BERGENS-FJORD”, was about to take place. As part of the survey, the crew had to lower the rescue boat to sea level according to the ship’s procedures.
The incident
On the evening of 6 December 2017, BERGENS-FJORD was berthed in Risavika in Norway, where an annual survey of the ship was about to take place with the participation of Danish and Norwegian maritime authorities. As part of the survey, the crew had to lower the rescue boat to sea level in accordance with the ship’s procedures.
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The shipping company and the ship’s crew considered the release of the boat to be associated with significant risk to the rescue boat crew. The ship’s
crew had heard about accidents happening while the rescue was being lowered, and was uneasy about the boat beginning to sway while at height. Thus, ship training exercises contained a practice, where the rescue boat was lowered to a door in the ship’s side, from where the crew boarded. As a result, the boat with crew was lowered the remaining few metres down to sea level.
At 9 PM, the chief officer loosened the rescue boat’s lashings, and the power supply cable was removed. Using the wire winch on the davit, the rescue boat was slowly lifted out of its cradle, upon which the davit should take the boat over the side of the ship. While the chief officer was operating the davit, the boat was suddenly released from the release hook and fell unmanned into the water from the seventh deck. The boat sustained extensive structural damage and slowly drifted away.
The crew gathered, and the lifeboat was launched to tow the rescue boat along the quay. Later, the rescue boat was brought ashore, and the release hook was removed and kept by the Danish Maritime Authority for further investigation.
The sister ship, STAVANGERFJORD, had the same rescue boat arrangement, and the company decided to stop the use of the rescue boat, until the cause of the incident had been established.
Probable cause
The reason why the rescue boat was unintentionally released was that when the rescue boat was hoisted out of the cradle, the release lever hit the arm of the davit and was impacted by such a downward force that the pin in the release lever was severed. The release lever could then drop down freely, releasing the pawl.
There were three reasons why this incident had not happened before:
- The release hook was usually turned in such a way that the handle pointed outwards and not inwards toward the davit. This meant that when the boat was hoisted out of the cradle, the release lever would not hit the davit.
- The boat was not always hoisted this far out of the cradle before the davit was lowered because the limit switch had been mounted further down the
hoisting wire on STAVANGERFJORD than on BERGENS-FJORD. - The information gathered indicates that the hook was attached to the boat’s suspension in such a way that the release lever pointed downwards and not upwards. The correct setting of the lever was upwards. The incorrect fitting of the hook, with the lever downwards, prevented the accidental release of the hook because the lever could not come into contact with the davit. However, in that case the emergency release would not work.
- The DMAIB has ascertained that, among crew and shipping companies, there is an understanding of the launching appliances as complete, approved systems, which are considered safe to use when they have been inspected and approved. The annual inspection of the launch appliance will not necessarily lead to the discovery of design problems, because the inspection is based on an assessment of the launch appliance’s mechanical reliability and the state of individual components at the time of inspection. The inspection of the launch appliance must be done at certain intervals. This means that if, over the course of the year, a wire or release hook is replaced, this will not prompt a new inspection of the launch appliance. The check of the system’s mechanical reliability will be left to the people who replaced the parts.
- On BERGENS-FJORD’s release hook, an instruction had been printed, which did not offer intuitive instructions on the use of the hook. In the absence of intuitive instructions, the crew adapted to the situation and developed a use of the hook which was perceived as being safe, meaning that they used the ‘On-load release’ method. This method ensured that the crew’s hands did not come into contact with the moving parts of the release hook. The crew’s way of using the release hook was not in accordance with the manual’s instructions, where ‘Off-load release’ was described as the ideal use of the hook. It is the assessment of the DMAIB that the manual’s instructions for ‘Off-load release’ could cause an increased risk of hand injuries because the manual did not address the operational circumstances under which rescue boats are launched. It should be borne in mind that when the rescue boat is at sea, it can move significantly, and the boat’s suspension wire can be difficult to work with. In situations like these, the boat’s crewmembers do not want their fingers close to the moving parts of the release hook.
