SAVANNAH, Ga. — As authorities try to answer why a cargo ship carrying 4,200 vehicles overturned on the Georgia coast, maritime experts say investigators will be looking for shifting cargo or other problems that upset the giant vessel's balance enough to make it fall onto its side.
The U.S. Coast Guard is leading the investigation into what caused the South Korean ship Golden Ray to capsize early Sunday soon after it departed the Port of Brunswick, about 70 miles south of Savannah. The ship's pilot and 23 crew members were all safely rescued, including four men trapped for 36 hours before they could be extracted through a hole drilled into the hull.
Measuring 656 feet long and 83 feet wide, the Golden Ray is roughly the size of a 70-story office building. Such vehicle carries tend to be ungainly and bulky, making them "like a floating shoebox," said Joseph Murphy, a retired ship captain and professor of marine transportation at Massachusetts Maritime Institute.
Keeping those ships upright requires a balancing act that involves distributing the weight of its cargo and fuel as well as water in the ship's ballast tanks, which fill to add weight and help lower a vessel's center of gravity.
"There's a lot of different things that could have happened here," said Jim Staples, who worked 17 years as a captain aboard vehicle carriers similar to the Golden Ray and is now a maritime consultant. "We definitely know there's a stability problem with the ship somewhere."
Staples said investigators will be asking whether vehicles in the cargo decks may have shifted and upset the ship's balance, and whether they were lashed down properly. Were the ballast tanks holding enough weight to keep the vessel steady? Staples said crews sometimes wait to fill ballast tanks until they reach open seas to keep muddy water and marine animals from getting sucked into the tanks.
Coast Guard officials have declined to say what might have caused the Golden Ray to list and flip onto its side. The National Transportation Safety board has assigned investigators to assist them.