On June 18, 2023, about 1047 local time, while diving to the wreck of the ocean liner Titanic in the North Atlantic Ocean, about 372 miles southeast of St. John’s, Newfoundland and Labrador, Canada, the submersible Titan’s pressure hull failed, and the vessel imploded. All five persons on board the vessel died. The Titan was a total loss; according to a 2023 customs declaration, the submersible’s value, combined with its launch and recovery system, was estimated at $5.6 million CAD (about $ 4.2 million USD).
We found that the Titan pressure vessel likely sustained damage after it surfaced at the end of dive 80 in the form of one or more delaminations, which weakened the pressure vessel. We found that after dive 82, the Titan sustained additional damage (of unknown origin) that further deteriorated and weakened the pressure vessel. The existing delaminations and additional damage that deteriorated the condition of the pressure vessel between dive 82 and the casualty dive (dive 88) resulted in a local buckling failure that led to the implosion of the Titan.
We found that OceanGate’s engineering process for the Titan was inadequate and resulted in the construction of a carbon fiber composite pressure vessel that contained multiple anomalies and failed to meet necessary strength and durability requirements. Because OceanGate did not adequately test the Titan, the company was unaware of the pressure vessel’s actual strength and durability, which was likely much lower than their target, as well as the implications of how certain operational changes, including storage condition and towing, could impact the integrity of the pressure vessel and overall safety of the vessel. Additionally, OceanGate’s analysis of Titan pressure vessel real-time monitoring data was flawed, so the company was unaware that the Titan was damaged and needed to be immediately removed from service after dive 80.
We found that, had OceanGate followed Navigation and Vessel Inspection Circular (NVIC) 05-93 guidance for emergency response plans, they likely would have had emergency response assets standing by, and the Titan likely would have been found sooner, saving time and resources even though a rescue was not possible in this case. Despite OceanGate’s failure to notify search and rescue assets about its planned expedition, as well as the limited resources able to operate at the depth of the Titanic, the US Coast Guard’s search and rescue coordination efforts were effective and resulted in the timely discovery of the Titan wreckage.
We found that voluntary guidance and current US small passenger vessel regulations are not sufficiently tailored to current pressure vessel for human occupancy (PVHO) operations to ensure the safety of PVHOs in accordance with established technical and classification society standards. Additionally, we found that international standards for PVHOs would ensure consistency in design, construction, and operation requirements for PVHOs that operate around the world.
We determined that the probable cause of the hull failure and implosion of the submersible Titan was OceanGate’s inadequate engineering process, which failed to establish the actual strength and durability of the Titan pressure vessel and resulted in the company operating a carbon fiber composite vessel that sustained delamination damage that was subsequently exacerbated by additional damage of unknown origin, resulting in a damaged internal structure that subsequently led to a local buckling failure of the pressure vessel. Contributing were US and international voluntary guidance and US small passenger vessel regulations that were insufficient to ensure OceanGate adhered to established industry standards. Also contributing was OceanGate’s flawed analysis of their pressure vessel monitoring system data, which led to their continued operation of a damaged pressure vessel.
As a result of this investigation, we recommended that the US Coast Guard commission a panel of experts to study current PVHO operations and disseminate findings of the study to industry. Additionally, we recommended that the US Coast Guard implement US regulations for PVHOs informed by the findings of the recommended study and consistent with international PVHO requirements and guidance. We also recommended that the US Coast Guard update NVIC 05-93 to include the revised definition of small passenger vessel as reflected in the Passenger Vessel Safety Act of 1993 and to reflect the findings of the recommended study. Finally, we recommended that the US Coast Guard propose that the International Maritime Organization make MSC.1/Circ. 981 mandatory to promote consistent application of pressure vessel for human occupancy rules amongst member states.
Read the complete list of recommendations.
