At approximately 11:00 p.m. on October 12th, 2009, the two 500,000 lb strength towlines connecting La Prinsesa barge to its tug broke free. The tug was unable to recapture the ship, and it drifted for about seven hours in heavy seas caused by a wind-driven rain storm before grounding at Sandbridge Beach in Virginia, just shy of the Sandbridge pier.
So far the 84 hazardous material (HAZMAT) loads the barge was carrying appear to be intact. There were no injuries, as the barge was unmanned. Damage to the ship is not known at this time. However, the incident had the potential to cause injuries, a HAZMAT spill that could have led to an evacuation, and far more damage to the ship and the beach. The incident did lead to the loss of the towlines, which are valued at approximately $70,000 and a delay in the barge’s arrival.
It’s unclear what caused the towlines to break free. Initial solutions are to clear the area and ballast the tug to attempt to keep it from drifting. On November 17, the barge began being towed to open waters where the cargo can be off-loaded safely. However, long-term solutions that would prevent another incident of this type will only be determined after the causes of the issue are determined.
Click on “Download PDF” to view a PDF showing the root cause analysis investigation based on what is known so far. A thorough root cause analysis built as a Cause Map can capture all of the causes in a simple, intuitive format that fits on one page. Even more detail can be added to the Cause Map as the analysis continues. As with any investigation the level of detail in the analysis is based on the magnitude of the impacts (or potential impacts).