The 9arm video about the Titan submersible was published in 2023 while the investigation was still underway. The speaker discussed underwater pressure, the vehicle’s materials and structure, and questions about testing and safety systems. This article separates what the video transcript covered from official findings published later.
Engineering Issues Discussed in the 9arm Video
The transcript distinguishes a submarine, which can travel underwater, from a submersible that relies on a support vessel. It explains that external pressure increases with depth. The speaker uses Titan’s pressure hull—made from carbon-fiber composite with titanium components—to discuss pressure, connections between materials, and the challenges of testing materials under external compression.
The video also discusses the interface ring, viewport, fatigue or material damage from repeated use, hull-monitoring systems, communications, and joystick controls. These are the speaker’s explanations and questions from that time; they are not all findings of the investigative board.
Questions in the Video and the Official Findings
The NTSB says Titan lost its pressure hull and imploded during a dive on June 18, 2023, killing five people. Its findings say the pressure vessel likely delaminated after dive 80 and sustained further damage after dive 82, before local buckling and implosion on dive 88.
The NTSB identifies the probable cause as OceanGate’s inadequate engineering process for demonstrating the strength and durability of the carbon-fiber-composite pressure vessel. Testing was insufficient, and analysis of hull-monitoring data was flawed, so the damage was not recognized and the vessel was not removed from service. See the NTSB Titan accident investigation.
The U.S. Coast Guard’s Marine Board of Investigation report, released in 2025, identifies major factors related to inadequate design, certification, maintenance, and inspection, including the failure to follow up on hull anomalies after the 2022 expedition. Read the U.S. Coast Guard summary of its findings.
How to Read the Video’s Hypotheses
Before the investigation was complete, the speaker raised several possibilities in the transcript, including fire, connection points, the viewport, and composite fatigue. These should be read as analysis at the time the video was published. For conclusions about the cause, use the later investigative reports. Do not conclude that the viewport, joystick, or connection point was the primary cause when the reports do not say that.
A verifiable lesson from the reports is that designs for real operating risks need testing evidence, a clear understanding of material limits, repeated inspections, and data analysis that can lead to taking equipment out of service when anomalies are found. The NTSB report also notes gaps in guidance and regulations for crewed pressure vessels.
Original Video, Channel, and Playlists
Watch the 9arm Titan submersible video, browse the 9arm channel page or the 9arm channel on YouTube, or open the Science and Engineering video category.
The saved membership record shows the video in all three playlists in the captured snapshot. Playlist membership establishes a YouTube relationship; it does not mean that a playlist recommends or endorses this article.