A transcription mistake and incorrect ballast documentation, both resulting in a low margin of stability, likely caused the yacht Baaden to capsize at Northern Marine last year. This, according to the National Transportation Safety Board (NTSB), the lead federal agency in the investigation.
The incident occurred during the launch of the 85-footer (25.9-meter) in May 2014. According to video footage, when Northern Marine maneuvered the cradle system carrying her into the water, she began listing to port. She rolled immediately thereafter. Five of eight Northern Marine staff onboard the megayacht required first responders’ assistance to escape. The remaining three suffered minor injuries. New World Yacht Building, doing business as Northern Marine, hired a salvage company to help right the yacht Baaden. A few days later, crews towed her with the assistance of support straps. They then hauled and placed her on cradles at another nearby dock. Despite transporting back to Northern Marine in July 2014, the yacht Baaden was a total constructive loss. Damage estimate: $10 million. Primarily, the figure represented water damage to the electrical system, machinery, and woodwork.
In its findings, the NTSB indicates, “the probable cause of the capsizing of the yacht Baaden during its initial launch was the vessel’s low margin of stability.” The agency points to a combination of causes. Initially, a recording error occurred during the final vessel weigh. This therefore resulted in incorrectly assessing her center of gravity. It additionally resulted in overestimating the weight of installed ballast.
During construction, as is practice, yard personnel weighed the yacht Baaden. They took numbers twice. Specifically, the goal was “to verify the accuracy of the ongoing estimates by placing several load cells (weight scales) under the vessel and summing the individual cell readings,” the NTSB states. During the first weight test, in July 2013, Baaden registered 76.9 long tons. This was five percent less than the estimate from Roddan Engineering, a stability naval architect which New World hired. Roddon Engineering had determined the final weight would be 130 long tons, with draft at 6’5”. Furthermore, Roddan Engineering estimated, Baaden would meet Coast Guard stability requirements with 25.93 long tons of installed ballast.
During the second weight test, though, in March 2014, weight was 124.1 long tons. This was higher than expected for her completion stage. Roddan Engineering therefore revised the anticipated final weight to be 154.1 long tons at a 7’2” draft.
NTSB investigators reviewed photos of the load cells from that second test and compared them to figures from Roddan Engineering. In doing so, the investigators discovered discrepancies. A photo of the aft starboard load cell revealed a weight of 60,550 pounds. Notably, shipyard staff additionally wrote the load cell figures in grease pencil on the cradle. They wrote the figure directly above the cell with the weight reading. However, for the aft starboard cradle, they wrote a weight of 60,350. Furthermore, “the investigation determined that New World supplied the stability naval architect a value of 68,500 pounds for this cell―indicating a transcription error at New World.” The naval architect subsequently used this incorrect number to determine total vessel weight and estimate launch stability.
As for the aft port load cell, the weight was 68,700 pounds. This meant it was 8,150 pounds heavier than the actual aft starboard reading. “The stability naval architect said this 8,000-pound difference indicated a transverse weight differential and would produce a heeling moment to the heavier port side,” according to the NTSB. “This meant the vessel’s center of gravity was further to port than had been estimated.”
Further complicating matters, the NTSB discovered a communication error involving Baaden’s installed ballast weight. Following the second weight test, New World informed Roddan Engineering that 23 long tons of ballast was aboard. The firm used that figure to calculate launch stability. However, after the capsizing, New World provided the NTSB with a ballast diagram indicating 16.61 long tons of ballast was aboard.
The NTSB investigators point out that engineers, managers, and others involved with the design and construction of the yacht Baaden had prior experience. Simultaneously, they point out that these same personnel had successfully built and launched similar vessels via the same methods. However, the NTSB concludes, “New World’s transcription error from the reading on a load cell and incorrectly reported ballast weight resulted in the contracted offsite naval architect inaccurately assessing launch stability. These errors indicate a breakdown in the technical oversight of the design and build process.”
New World Yacht Building went out of business in August 2014.
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