MAC is pleased to pass on this editted internal company investigation into the separation of a mooring wire from its rope tail during the mooring of a tanker due to the failure of a MANDAL shackle. Periodic checks did not prevent the incident. The Safety Management System procedures were lacking and did not identify the need to carry out the necessary checks on mooring equipment lines and fittings prior to mooring the vessel.
The tanker was scheduled to berth at San Francisco, Martinez Shell Terminal. To position the vessel it was agreed to pass one forward spring and one after spring line as first lines. The vessel is equipped with mooring wires of 38mm diameter on drums and fitted with an 11 metre polyamide mooring tail.
The wire and tail are joined together using a MANDAL Mooring link.
At 0400 hours it was ascertained that the vessel was in position and both stations were asked to tighten the spring lines and secure. When the forward station was tightening its spring line to secure it reported that the mooring wire had separated from the rope tail.
When the rope tail was retrieved it was observed that the mooring link had flared open. The roller and securing pin was missing and presumed lost to sea.