An accident investigation report by the Luxembourg authorities into the sinking of the vessel Bourbon Rhode with the tragic loss of four people on 26 September 2019 in the Atlantic Ocean has revealed a serious safety flaw of significance. The Luxembourg authorities have released an urgent safety bulletin as a consequence.
The Bourbon Rhode, an anchor handling tug, sank on September 26 in the Atlantic Ocean during a transit voyage from Las Palmas to Guyana.
The Bourbon Rhode was equipped with a system called shark jaws, which is installed in the aft Z-Drive compartment to secure chains or wires during anchor handling operations. When operating, water from the deck can enter the watertight housing frame, which has three drain fittings at the bottom plate. When not in use, the shark jaws are lowered into the housing frame and sit flush with the deck. In the lowered position, gaps around the shark jaws allow water to enter the housing frame.
Probable Causes
– The investigation has revealed that under unfavorable circumstances, the water quantity penetrating the compartment is likely to increase up to a point where, when unnoticed or unattended for a certain period of time, an unsafe condition may develop and lead to major flooding with subsequent foundering.
– In addition, the investigation has found other anchor handling vessels in the fleet with similar leaking inspection covers within the anchor handling system. This means that the compromised watertightness of the anchor handling system with these particular types of inspection covers is not an isolated instance and is most likely to be encountered in other similar vessels too.
Immediate safety recommendation
The Bourbon Rhode report highlights that as an immediate safety measure, it is recommended to put in place an additional safety barrier through the SMS by implementing a procedural defence to limit the risk of flooding from leaking inspection covers of anchor handling systems.
Along with the existing maintenance instructions, the report notes the following as safety actions to be taken:
– Preventive actions to mitigate the risk of water ingress through the inspection openings during maintenance tasks on the anchor handling systems (e.g. sea state limitations, installation of anchor handling system deck cover plates);
– Instructions for the appropriate sealing method when installing the inspection covers to ensure the water tightness of the anchor handling system housing (e.g. application of silicone sealant, installation of gasket);
– Instructions for testing the water tightness of the anchor handling system after completion of the works and installation of the inspection covers (e.g. flooding of anchor handling system housing frame with closed drainage by use of fire hose);
– Maintenance actions to prevent degradation of the inspection covers and securing devices, which could compromise the water tightness of the anchor handling system;
– Appropriate documentation of the actions performed during the maintenance work.
During anchor handling activities, the manufacturer recommends maintenance of the shark jaws to be carried out once every week. One maintenance item is to remove the inspection covers at the side of the housing and to clean and remove sand, mud, or any obstructions from the inside of the housing frame. Upon completion of the maintenance, the inspection covers are to be installed with silicone sealant and gasket.
The Luxembourg Administration advises all operators of vessels equipped with the Plimsoll Smith Berger Hydraulic Shark Jaw system P3679-350MTTA or anchor handling systems with similar designs of the inspection covers to implement in the vessel operator’s Safety Management System a standard procedure for tasks requiring the opening of the inspection covers of the anchor handling system housing frame.
Read the pdf safety bulleting: Bourbon Rhode safety bulletin