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It was just the end caps that were titanium - the entire tube was just a 5inch thick carbon fiber wrap. In one of the videos with the CEO I saw him saying that

It was just the end caps that were titanium - the entire tube was just a 5inch thick carbon fiber wrap. In one of the videos with the CEO I saw him saying that he was a rule breaker because common consensus was that you shouldn't build a submarine out of carbon fiber and titanium.

jonah 3y ago
It was actually the second try at a CF tube. The first had flaws and issues and was either "repaired" or replaced by other manufacturing companies.
- jonah 3y ago
  Reference to the repair/replacement of the cf tube: https://techcrunch.com/2023/06/20/a-whistleblower-raised-safety-concerns-about-oceangates-submersible-in-2018-then-he-was-fired https://techcrunch.com/2023/06/20/a-whistleblower-raised-saf... "The Spencer-built composite cylindrical hull either was repaired or replaced by Electroimpact and Janicki Industries in 2020 or 2021, prior to the first trips to Titanic."
mechhacker 3y ago
I'd really like more detail on that tube's layup schedule. Solid 5inch thick carbon composite OR a sandwich design with thick outer facesheets of carbon fiber? I suppose under that pressure not much would take the hydrostatic loads other than carbon, but that seems thick compared to everything I've seen made out of composites.
- floxy 3y ago
  Here's a write-up on the composite part of one of Oceangate's vessels: https://www.compositesworld.com/articles/composite-submersibles-under-pressure-in-deep-deep-waters https://www.compositesworld.com/articles/composite-submersib... ...since that article is from 2017, it is not clear that this was the unit that actually failed.
  - mechhacker 3y ago
    Very interesting. Ties sub tech to Steve Fossett, who was working with Scaled Composites before his death. Not saying they are related at all but I am reminded of this: https://en.wikipedia.org/wiki/VSS_Enterprise_crash https://en.wikipedia.org/wiki/VSS_Enterprise_crash
- saberdancer 3y ago
  There are videos of them building it. From what I remember, they rolled carbon fiber around a cylinder, making the flat part of the cylinder. Then they mated two titanium half spheres to the end of the carbon fibre cylinder. This was done using some kind of "glue". Meaning that the middle part had no titanium. I think it was in Sub brief YouTube video. https://www.youtube.com/watch?v=4dka29FSZac&pp=ygUJc3ViIGJyaWVm https://www.youtube.com/watch?v=4dka29FSZac&pp=ygUJc3ViIGJya...
  - mechhacker 3y ago
    Thanks, I see now. Wow, that's a thick layup.
- SirSourdough 3y ago
  I saw a bit of video where they showed the construction- it’s a few inch wide band of carbon fibre wrapped around an inner tube like a spool of thread until it reaches 5” thickness.

jonah 3y ago

It was actually the second try at a CF tube. The first had flaws and issues and was either "repaired" or replaced by other manufacturing companies.

jonah 3y ago
Reference to the repair/replacement of the cf tube: https://techcrunch.com/2023/06/20/a-whistleblower-raised-safety-concerns-about-oceangates-submersible-in-2018-then-he-was-fired https://techcrunch.com/2023/06/20/a-whistleblower-raised-saf... "The Spencer-built composite cylindrical hull either was repaired or replaced by Electroimpact and Janicki Industries in 2020 or 2021, prior to the first trips to Titanic."

mechhacker 3y ago

I'd really like more detail on that tube's layup schedule. Solid 5inch thick carbon composite OR a sandwich design with thick outer facesheets of carbon fiber? I suppose under that pressure not much would take the hydrostatic loads other than carbon, but that seems thick compared to everything I've seen made out of composites.

floxy 3y ago
Here's a write-up on the composite part of one of Oceangate's vessels: https://www.compositesworld.com/articles/composite-submersibles-under-pressure-in-deep-deep-waters https://www.compositesworld.com/articles/composite-submersib... ...since that article is from 2017, it is not clear that this was the unit that actually failed.
- mechhacker 3y ago
  Very interesting. Ties sub tech to Steve Fossett, who was working with Scaled Composites before his death. Not saying they are related at all but I am reminded of this: https://en.wikipedia.org/wiki/VSS_Enterprise_crash https://en.wikipedia.org/wiki/VSS_Enterprise_crash
saberdancer 3y ago
There are videos of them building it. From what I remember, they rolled carbon fiber around a cylinder, making the flat part of the cylinder. Then they mated two titanium half spheres to the end of the carbon fibre cylinder. This was done using some kind of "glue". Meaning that the middle part had no titanium. I think it was in Sub brief YouTube video. https://www.youtube.com/watch?v=4dka29FSZac&pp=ygUJc3ViIGJyaWVm https://www.youtube.com/watch?v=4dka29FSZac&pp=ygUJc3ViIGJya...
- mechhacker 3y ago
  Thanks, I see now. Wow, that's a thick layup.
SirSourdough 3y ago
I saw a bit of video where they showed the construction- it’s a few inch wide band of carbon fibre wrapped around an inner tube like a spool of thread until it reaches 5” thickness.