by writeslowly on 9/17/24, 12:42 AM with 36 comments
by angelgonzales on 9/17/24, 3:03 AM
“ 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.”
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.
by nxobject on 9/17/24, 3:29 AM
by shiroiushi on 9/17/24, 4:06 AM
by Tossrock on 9/17/24, 5:32 AM
During the prototype phase:
"June 2019: OceanGate pilot visually identified a large crack on the internal surface of the carbon fiber hull."
"October 2019: TITAN tested at Deep Ocean Test Facility. Hull showed signs of fatigue, hull derated to 3000M."
On the first expedition:
"Conducted 1 test dive (dive #63) to depth on TITANIC (3,840M) before carrying paying passengers/ “mission specialists"
• 70 equipment issues requiring correction including:
• forward dome fell off during recovery,
• multiple drop weight issues to include the tray being jettisoned due to malfunction,
• drop weight and thruster failure at 3,500M, and
• platform damaged on recovery."
On the last expedition:
"Mission #2 (May 20 – May 28)
• 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."
And maybe the worst, on the penultimate mission before its total constructive loss:
"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."
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.
by aaron695 on 9/17/24, 3:20 AM
The last message "dropped two wts" was normal and just slowing the descent - https://www.youtube.com/watch?v=avp_-wN3ekA&t=29460s
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.
If you open "transcript" you can "Control+F" anything you might want to hear, but it's all pretty interesting.