A transcription mistake and incorrect ballast documentation, both resulting in a low margin of stability, likely caused the 85-foot (25.9-meter) Baaden to capsize at launch at Northern Marine last year. The word comes from the National Transportation Safety Board (NTSB), which was the lead federal agency in the investigation.
The incident occurred in May 2014. Video of the launch process shows that when Northern Marine maneuvered the dolly holding Baaden into the water, she began listing to port and then rolled. Five Northern Marine staff aboard Baaden required assistance from first responders to escape. Three suffered minor injuries. New World Yacht Building, which was doing business as Northern Marine, hired a salvage company to help right the yacht, using straps. A few days later, Baaden was towed with the assistance of support straps, then hauled and placed on cradles at another nearby dock. Even though she was transported back to Northern Marine in July 2014, she was deemed a total constructive loss, estimated at $10 million. It was due to water damage of the electrical system, machinery, and woodwork, and the cost to replace all of it.
According to the NTSB, which issued its report in late July, “the probable cause of the capsizing of the yacht Baaden during its initial launch was the vessel’s low margin of stability due to the combined effects of a recording error during the final vessel weigh, which resulted in an incorrect assessment of the vessel’s center of gravity, and an overestimation of the weight of installed ballast.”
Regarding weight and the center of gravity, Baaden was analyzed during the construction process, as is typical. She was weighed twice during construction, “to verify the accuracy of the ongoing estimates by placing several load cells (weight scales) under the vessel and summing the individual cell readings,” according to the NTSB report. During the first weight test, in July 2013, Baaden registered 76.9 long tons, five percent less than the estimate. Roddan Engineering, an independent stability naval architect hired by New World for the project, estimated that Baaden’s final weight would be 130 long tons at a 6’5” draft. Furthermore, Roddan Engineering estimated, Baaden would meet Coast Guard stability requirements with 25.93 long tons of installed ballast. During the second weight test, in March 2014, her weight was 124.1 long tons, higher than expected for her level of completion. Roddan Engineering therefore revised the anticipated final weight to be 154.1 long tons at a 7’2” draft.
When NTSB investigators reviewed photos of the load cells from that second test, comparing them to the figures supplied to Roddan Engineering, they discovered discrepancies:
The photograph of the aft starboard load cell showed a value of 60,550 pounds. Additionally, the investigation determined the load cell values were written in grease pencil on the cradle above the cell from which they were taken. An aft starboard pencil value of 60,350, nearly similar to the value shown in the cell photograph, was found written on the cradle. However, 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―and the naval architect used this incorrect weight in his spreadsheet to determine total vessel weight and estimate launch stability. As the aft port load cell reading was 68,700 pounds, an actual aft starboard side reading of 60,550 was more than 8,000 pounds less than the aft port side. 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. This meant the vessel’s center of gravity was further to port than had been estimated.
Further complicating matters, the NTSB discovered that Baaden’s installed ballast weight was incorrectly communicated. Following the second weight test, New World informed Roddan Engineering that 23 long tons of ballast was installed. 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 report concludes, “Engineers, managers, and other personnel involved with the design and construction of the Baaden were experienced and had successfully built and launched similar vessels in the same manner in the past. However, 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.
To download the full report on the capsizing of Baaden, visit the NTSB accident report page.
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