It is so rare to get in-depth FEA reports like what you’ve linked us here. Here’s what Boeing states in the report:<p>“ There is still detail design work that will need to be completed. However, both the C4 and C11 configurations come close to an acceptable conceptual design. A small test program would be needed to address some of the outstanding questions. Additional modeling and optimization are also needed at the detail design level. The inclusion of portals, motor attachments, tanks and other peripherals would need to be included in a final analysis.
More work needs to be done to define thermal load and cure shrinkage for both the composite cylinder and for the bonded joint. This composite structure is much thicker than most of the structure currently being produced. Thermal strains may play a significant role in the design of the structure. The time required for fabrication and the extended time that the material will be at elevated temperature during cure and bonding needs to be examined. These topics were mostly avoided during the first part of the design cycle. This report describes a conceptual design and a preliminary feasibility study. The design is feasible, but will require additional work in the areas of manufacturing, cure kinetics, material allowable, assembly, and dimensional tolerance.”<p>In summary - even if Oceangate developed a robust design, they’d still need to manufacture the submarine. It appears they never built enough test articles to develop a baseline for robustness, because they never did destructive testing at depth with actual hardware they never knew their margins and were never able to validate their models to reality.
It's interesting to note how an animation was developed in the course of this investigation. I know the Chemical Safety Board does similar animations for industrial accidents. [1]<p>[1] <a href="https://www.csb.gov/videos/" rel="nofollow">https://www.csb.gov/videos/</a>
I just saw a news headline that the estate of the oceanographer who died on the Titan is suing the company for $50M. How exactly is this possible? Who are they suing? I didn't think there even was an OceanGate company in existence any more: their founder is dead, and no one in their right mind would ride on one of their subs any more, so what assets do they even have to sue for? They weren't some big tech company with billions in assets; they were some crappy little start-up trying to build a business by selling cheap submersible rides to rich people, and from what I remember, didn't exactly have solid financials at the time and certainly no extra money in the bank to sue for. And IIRC the business didn't have any kind of liability insurance, so what is the point of a big wrongful-death lawsuit against a defunct company with no assets?
The Basic Factual Information presentation is pretty astonishing. There were so many opportunities to stop and reflect on what a bad idea this whole enterprise was.<p>During the prototype phase:<p>"June 2019: OceanGate pilot visually identified a large crack on the internal surface of the carbon fiber hull."<p>"October 2019: TITAN tested at Deep Ocean Test Facility. Hull showed signs of fatigue, hull derated to 3000M."<p>On the first expedition:<p>"Conducted 1 test dive (dive #63) to depth on TITANIC (3,840M) before carrying paying passengers/ “mission specialists"<p>• 70 equipment issues requiring correction including:<p>• forward dome fell off during recovery,<p>• multiple drop weight issues to include the tray being jettisoned
due to malfunction,<p>• drop weight and thruster failure at 3,500M, and<p>• platform damaged on recovery."<p>On the last expedition:<p>"Mission #2 (May 20 – May 28)<p>• POLAR PRINCE departed St. Johns on May 20th enroute TITANIC with TITAN in tow at an average speed of 7.4 knots (8.4 mph). May 22nd, conducted unmanned dive to 8 meters (Dive 84). On May 24th, after a night of high seas and fog, the TITAN and its platform were found partially sunk in the morning with the tail cone fairing ripped off. May 27th conducted post incident test dive, recorded 13 equipment issued requiring correction."<p>And maybe the worst, on the penultimate mission before its total constructive loss:<p>"On June 12th, while conducting Dive# 87, TITAN experienced a variable ballast tank issue, upon resurfacing, an error caused platform to become inverted to ~45 degrees with the bow of the TITAN up, slamming all 5 persons to the aft of the submersible. The TITAN became partially disconnected to the LARS and with the approximate 6 foot [seas?], slammed the submersible and the occupants for ~1 hour until the platform was corrected."<p>Spending an hour being slammed around in an oversized washing machine really should have given someone time to consider whether maybe their reach was exceeding their grasp. Unbelievable hubris.
The first days live stream (as linked) is pretty interesting. It's 9 hours, of 9 days - <a href="https://www.youtube.com/watch?v=avp_-wN3ekA&list=PLgOje37c-b1NswzbM8kMEGRrdup_xwlW9&index=1" rel="nofollow">https://www.youtube.com/watch?v=avp_-wN3ekA&list=PLgOje37c-b...</a><p>The last message "dropped two wts" was normal and just slowing the descent - <a href="https://www.youtube.com/watch?v=avp_-wN3ekA&t=29460s" rel="nofollow">https://www.youtube.com/watch?v=avp_-wN3ekA&t=29460s</a><p>CNN puts it as - "dropped two wts" - the Titan’s text to its mother ship read, referring to weights the submersible could shed in hopes of returning to the surface.<p>If you open "transcript" you can "Control+F" anything you might want to hear, but it's all pretty interesting.