The USCG issued an alert informing that recently, there have been a number of shore side marine bollard failures whereby moored vessels were cast adrift. In some cases, this resulted in damage to the involved vessel, as well as other nearby vessels and shore side structures, the USCG warned.
Neither the USCG nor the Occupational Safety and Health Administration (OSHA) has regulatory oversight over these items. In several cases, the underlying deficient material condition of the bollards was unknown until the failures occurred.
Key causes include:
– the rotting of organic bollards made of marine pilings,
– the undetected fracture of bollard castings due to manufacturer defects,
damage from previous overloads, or
– the degradation of bollard foundations and fasteners.
Typically, the failures are associated with abnormal dynamic loads transferred to the bollard from a vessel. The abnormal loads are oftentimes caused by excessive winds acting against the sail area of vessels which can be substantial for certain types of vessels such as container and cruise ships. Forces developed by winds acting against a vessel’s hull rise exponentially as the wind speed increases and, as a result, are often extreme.
Also, vessel operators often encounter facilities that have an insufficient number of bollards or not enough bollards in the correct locations to ensure good marine mooring practices are followed. Finally, circumstances associated with bollard failures may relate to the hydrodynamics of narrow waterways, specifically when a large vessel approaches and passes a moored vessel.
The Coast Guard strongly recommends that facility owners and operators take steps to develop a routine inspection program for bollards and other mooring equipment. Furthermore, vessel personnel should report discoveries of apparently deficient shore side mooring equipment to facility managers.