Executive Summary
The tank barges Nash and Kenny were fully loaded with liquid
magnesium chloride and being towed by the uninspected towing vessel Calvin from
Guerrero Negro, Mexico, to British Columbia, Canada, when the Nash began to
list noticeably to its starboard side about 1145 on June 8, 2014.
Listing and trimming by the stern increased over the next 6
hours, and the US Coast Guard directed the Calvin captain to tow the Nash to a
nearby anchorage.
About 1805, the Nash sank stern first in 240 feet of water,
about 3 nautical miles west of Point Conception, California.
About a week after the sinking, a salvage team partially
refloated the Nash and towed it to its disposal location about 17 nautical
miles from shore.
Probable Cause
The National Transportation Safety Board determines that the
probable cause of the sinking of tank barge Nash was flooding of the aft
starboard side void tank.
The mechanism for entry of flooding water to this tank could
not be determined because the barge was not salvaged and was not available for
examination after it sank.