Image: NTSB
The failure of the doubler-plated hull below the engine room doubtless brought on the flooding and sinking of the 1978-built fishing vessel Grace Marie close to Gloucester, Mass., final 12 months, the National Transportation Safety Board stated Tuesday.
The Grace Marie, owned by AGV Company Ltd, was transiting to fishing grounds on July 8, 2022, when the engine room started flooding. The seven-person crew was unable to take away the water with the vessel’s bilge pumping system. The crew deserted the vessel in a life raft and was rescued by a Good Samaritan vessel. The vessel finally sank and was a complete loss valued at $650,000. No accidents had been reported.
The exterior space of the hull alongside the keel and below the engine room was lined with metal doubler plating to cowl and reinforce areas of deteriorated metal. It had been put in 8-10 years earlier than the vessel sank.
A doubler plate is a small piece of plate that’s connected to a bigger space, to supply strengthening in that location. According to the NTSB, it’s common for uninspected industrial fishing vessels such because the Grace Marie to make use of doubler plating to restore and reinforce broken or wasted underwater hull sections.
This could be very completely different from what’s permissible for towing vessels lined by Subchapter M and the NTSB cites a Coast Guard guidance on using doubler plates given the towing trade.
Doubler plate repairs can result in elevated stress concentrated within the space of the restore. Doubler plating additionally inhibits the power to evaluate the true situation of the hull.
The NTSB decided the possible reason behind the flooding and sinking of the Grace Marie was uncontrolled flooding of the engine room from an undetermined supply, doubtless a failure of the doubler-plated hull beneath the engine room.
“Although doubler plating can be used as a temporary repair solution, it is not generally suitable as a permanent repair for a vessel’s hull,” the report stated. “Vessel owners should crop out wasted steel on the hull and replace it by inserting new plating instead of covering it up with doubler plating.”
