A recent incident under investigation by the Marine Accident Investigation Branch (UK) provides a reminder that minimum standards are just that and that the practices of good seamanship and a well established safety culture are the true guardians of safety.
Two crewmen were hospitalised and one died recently in an accident during a routine launching and recovery of a vessels rescue craft. The fall wire attached to the rescue boat parted during a routine drill which was being conducted in the sheltered waters. The rescue boat had been hoisted to its stowed position when the incident took place and the boat and its’ four crew fell nearly 29m into the water.
The rescue boat had a certified weight of less than 1 tonne but when later weighed during investigation was found almost 48% heavier than stated. This increase in weight should not have resulted in the failure of its fall wire due to the safety margins in place and investigation into the failure of the wire remains ongoing.
The Rescue craft was constructed with an inner and outer hull, the voids below deck were divided into 16 compartments, 15 of which were filled with rigid polyurethane foam to provide a watertight, buoyant volume. The rescue craft was fully certified and met the requirements of SOLAS, the Life Saving Appliance (LSA) Code etc…
Investigation has identified that 14 of the 15 foam-filled compartments had been penetrated by water. In addition, the foam in the lower sections of the hull contained cavities and there were voids between the foam and the hull.
Although the boat was fitted with a drain plug on the transom, the internal compartments were not interconnected and there was no designed way to drain water that may have made its way into the internal compartments.
Water ingress and retention within a foam-filled internal compartment of a rescue craft is a serious cause for concern and can have to following consequences:
The use of foam-filled compartments in the construction of rescue craft is common throughout the industry and it is possible that the problems of water ingress and retention within a foam filling may not be limited to any single type or make of craft.
Owners and managers of vessels that use rescue boats or fast rescue craft built with integral polyurethane foam-filled compartments should:
Source of Information:
SIGTTO - Safety alert
(MAIB Safety bulletin: 1/2011)