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> According to the court documents, in a 2018 case, OceanGate employee David Lochridge, a submersible pilot, voiced concerns about the safety of the sub. 2018;

> According to the court documents, in a 2018 case, OceanGate employee David Lochridge, a submersible pilot, voiced concerns about the safety of the sub. 2018; this would make it the previous model, no? Not the same submarine that went missing. At least that's the impression I get from this article (2020): https://www.geekwire.com/2020/oceangate-raises-18m-build-bigger-submersible-fleet-get-set-titanic-trips/ https://www.geekwire.com/2020/oceangate-raises-18m-build-big... > "That meant the Titanic trips — which had been planned at first for 2018, then 2019, then 2020 — had to be put off until mid-2021. By that time, Rush expects the new submersibles to be ready to enter service." It's my impression that one of those "new submersibles" is the one that's lost.

sho_hn 3y ago
I was also curious about the timeline of this. I'm waiting for that one geeky blog post that integrates all the facts. I'm particularly interested in an educated perspective on their choice in materials. I'm familiar with carbon fibre from bike frame building, and the common tricks/practices to try and look for fissures, find voids/delaminations, etc. after a crash, and it's such a complex subject and material. I wonder who manufactured this vessel and what the quality of their facilities, tools, processes was.
- EamonnMR 3y ago
  I wonder if the NTSB will do a report on this.
- jvm___ 3y ago
  It's also the only planned trip for the company this year due to weather. So the sub has sat for a period of time before being put in use. Do you think they do extensive trial runs first at the beginning of each season? Like send it to the bottom un-manned just to double check? As my former boss liked to say "Things that aren't tested don't work."
  - prmoustache 3y ago
    I think they can't even send it un-manned because it is not externally controllable. From what I understood in footage of a previous "mission", all is operated on board and there is nothing the ship crew can do appart from communicating (when it still works).
    - salawat 3y ago
      ...well... Then clearly they should have put more time into the control system to allow for remote control from a submerged audio relay? We've got more than enough ways to rig up signalling networks that there is zero reason for any submersible to not be remotely tested to crush depth.
- c00lio 3y ago
  My educated (a little bit of engineering at uni) perspective is: Completely idiotic to build a submarine out of carbon and not have the means for a complete inspection for manufacturing defects as the original article suggests. Carbon, as you correctly note, needs to be very homogeneous. Bubbles, lamination defects or -god beware- fissures lead to failure, of the sudden, unannounced and total kind. And not only is it necessary to check after production, but also after regular short intervals of use, because a mere scratch in the carbon can be fatal.
  - johnvanommen 3y ago
    It seems utterly bizarre to make a sub out of carbon fiber. The advantage of CF is low weight. But who cares what a submarine weighs? Some of the articles about it's construction indicate that many of the engineers were aerospace engineers. I wouldn't want a submarine engineer designing a plane, and vice versa.
    - deleted 3y ago
      [deleted]
    - tim333 3y ago
      I was thinking about that but a steel sub can only really weigh as much as the same volume of water which probably limits things if you are going to 4000m. Too much weight and it'd sink like a stone.
    - civilitty 3y ago
      > The advantage of CF is low weight. But who cares what a submarine weighs? The heavier a sub is the bigger the ballast tanks have to be to compensate and the more energy is wasted on moving it, just like any other powered vehicle.
      - zardo 3y ago
        Do they even have ballast tanks? I saw mention of steel ballast they drop at the bottom. The biggest benefit of reduced weight on this thing would be minimizing the size of the crane and surface vessel needed to deploy and recover it.
- mcpackieh 3y ago
  I expect there will be a lot of books documenting every angle of this incident, if for no other reason than because of the Titanic connection. I'm looking forward to reading the whole story on how this incident happened.
- Prickle 3y ago
  https://www.youtube.com/watch?v=4dka29FSZac https://www.youtube.com/watch?v=4dka29FSZac Here is a quick and dirty analysis from a US Submariner of 20 years. It is supposedly, incredibly hard to find defects or damage on carbon fiber. SpaceX did cite this as a reason for using stainless steel. His belief is that there was a hull failure somewhere on the carbon fiber hull; a failure point that simply wasn't found before this dive.
  - throw9away6 3y ago
    It depends on the material system they used. It is possible to scan for defects just need expensive equipment. Loading and unloading a sub like this could easily result in damages that aren’t detected though
eterm 3y ago
That may be true but it still speaks to the company culture.
eigenspace 3y ago
The article talks about how this was to do with their 1/3 scale model. I guess the relevant question then is if the "new model" is just the old 1/3 model scaled up, or if there are important differences. Are they still using a viewport that's not certified for the depths they're reaching? Are they still using flammable materials? Are there still parts in danger of de-laminating? Do they still have a culture and pattern of covering up and lying about safety? If there were relevant changes to the new model other than scaling it up, it'd need to go through a much lengthier certification and testing phase.
idop 3y ago
This doesn't tell us whether new submersibles were ever built.
aredox 3y ago
Even if that is the case, the ethos of the company was to dismiss safety concerns, use inappropriate hardware, stonewall and then fire the only person who cared. People died. I do hope the CEO isn't one of them, because he needs to be thrown in front of a court. Same with the other senior executives and HR.
- misiti3780 3y ago
  no one died yet...
  - redtexture 3y ago
    Now all dead. Apparently on the way down.
  - aredox 3y ago
    Everybody was already dead.
  - CydeWeys 3y ago
    They could all easily already be dead. We simply don't know.
    - wkat4242 3y ago
      If indeed that viewport collapsed at 4000m as the article suggests, they probably didn't even have time to realize they were dying.
      - euroderf 3y ago
        Relatively, exceedingly merciful.
      - misiti3780 3y ago
        How long would it take to get down to 4000m though, didnt they lose contact like 1 hour in?
cpleppert 3y ago
They don't advertise any of their "new submersibles" on the website and the specifications they claim for Titan don't match any of their new submersibles; Titan is rated to go to the Titanic and not any lower. Titan isn't a previous version either. Unless they shelved the first Titan they probably just added some strengthening and called it a day. I'm blown away that for a sub of that size and shape they used carbon fiber. The sub is positively gigantic and a cylinder is very susceptible to failure after repeated cycles. I'm pretty sure the claims they made about working with NASA and having a system to monitor the structural integrity of the sub are just BS.
- xarope 3y ago
  "working with NASA"... "Hi Bob, did you used to work at NASA in the 60's? Can I ask, do you think this 1/100th scale submarine could get to this 1/100th scale titanic in my bathtub? kthxbye"
- MagicMoonlight 3y ago
  They found that their previous design with the same materials would get crushed at 2000m. And now this sub disappeared during descent…
rsynnott 3y ago
Based on the Wikipedia page, it _seems_ to be the same one? https://en.wikipedia.org/wiki/OceanGate,_Inc.#Titan_(4000_meters) https://en.wikipedia.org/wiki/OceanGate,_Inc.#Titan_(4000_me... It took a while to go from dismissing employee concerns to tourism, but it seems to be the same device.

sho_hn 3y ago

I was also curious about the timeline of this. I'm waiting for that one geeky blog post that integrates all the facts. I'm particularly interested in an educated perspective on their choice in materials. I'm familiar with carbon fibre from bike frame building, and the common tricks/practices to try and look for fissures, find voids/delaminations, etc. after a crash, and it's such a complex subject and material. I wonder who manufactured this vessel and what the quality of their facilities, tools, processes was.

EamonnMR 3y ago
I wonder if the NTSB will do a report on this.
jvm___ 3y ago
It's also the only planned trip for the company this year due to weather. So the sub has sat for a period of time before being put in use. Do you think they do extensive trial runs first at the beginning of each season? Like send it to the bottom un-manned just to double check? As my former boss liked to say "Things that aren't tested don't work."
- prmoustache 3y ago
  I think they can't even send it un-manned because it is not externally controllable. From what I understood in footage of a previous "mission", all is operated on board and there is nothing the ship crew can do appart from communicating (when it still works).
  - salawat 3y ago
    ...well... Then clearly they should have put more time into the control system to allow for remote control from a submerged audio relay? We've got more than enough ways to rig up signalling networks that there is zero reason for any submersible to not be remotely tested to crush depth.
c00lio 3y ago
My educated (a little bit of engineering at uni) perspective is: Completely idiotic to build a submarine out of carbon and not have the means for a complete inspection for manufacturing defects as the original article suggests. Carbon, as you correctly note, needs to be very homogeneous. Bubbles, lamination defects or -god beware- fissures lead to failure, of the sudden, unannounced and total kind. And not only is it necessary to check after production, but also after regular short intervals of use, because a mere scratch in the carbon can be fatal.
- johnvanommen 3y ago
  It seems utterly bizarre to make a sub out of carbon fiber. The advantage of CF is low weight. But who cares what a submarine weighs? Some of the articles about it's construction indicate that many of the engineers were aerospace engineers. I wouldn't want a submarine engineer designing a plane, and vice versa.
  - deleted 3y ago
    [deleted]
  - tim333 3y ago
    I was thinking about that but a steel sub can only really weigh as much as the same volume of water which probably limits things if you are going to 4000m. Too much weight and it'd sink like a stone.
  - civilitty 3y ago
    > The advantage of CF is low weight. But who cares what a submarine weighs? The heavier a sub is the bigger the ballast tanks have to be to compensate and the more energy is wasted on moving it, just like any other powered vehicle.
    - zardo 3y ago
      Do they even have ballast tanks? I saw mention of steel ballast they drop at the bottom. The biggest benefit of reduced weight on this thing would be minimizing the size of the crane and surface vessel needed to deploy and recover it.
mcpackieh 3y ago
I expect there will be a lot of books documenting every angle of this incident, if for no other reason than because of the Titanic connection. I'm looking forward to reading the whole story on how this incident happened.
Prickle 3y ago
https://www.youtube.com/watch?v=4dka29FSZac https://www.youtube.com/watch?v=4dka29FSZac Here is a quick and dirty analysis from a US Submariner of 20 years. It is supposedly, incredibly hard to find defects or damage on carbon fiber. SpaceX did cite this as a reason for using stainless steel. His belief is that there was a hull failure somewhere on the carbon fiber hull; a failure point that simply wasn't found before this dive.
- throw9away6 3y ago
  It depends on the material system they used. It is possible to scan for defects just need expensive equipment. Loading and unloading a sub like this could easily result in damages that aren’t detected though

eterm 3y ago

That may be true but it still speaks to the company culture.

eigenspace 3y ago

The article talks about how this was to do with their 1/3 scale model. I guess the relevant question then is if the "new model" is just the old 1/3 model scaled up, or if there are important differences. Are they still using a viewport that's not certified for the depths they're reaching? Are they still using flammable materials? Are there still parts in danger of de-laminating? Do they still have a culture and pattern of covering up and lying about safety? If there were relevant changes to the new model other than scaling it up, it'd need to go through a much lengthier certification and testing phase.

idop 3y ago

This doesn't tell us whether new submersibles were ever built.

aredox 3y ago

Even if that is the case, the ethos of the company was to dismiss safety concerns, use inappropriate hardware, stonewall and then fire the only person who cared. People died. I do hope the CEO isn't one of them, because he needs to be thrown in front of a court. Same with the other senior executives and HR.

misiti3780 3y ago
no one died yet...
- redtexture 3y ago
  Now all dead. Apparently on the way down.
- aredox 3y ago
  Everybody was already dead.
- CydeWeys 3y ago
  They could all easily already be dead. We simply don't know.
  - wkat4242 3y ago
    If indeed that viewport collapsed at 4000m as the article suggests, they probably didn't even have time to realize they were dying.
    - euroderf 3y ago
      Relatively, exceedingly merciful.
    - misiti3780 3y ago
      How long would it take to get down to 4000m though, didnt they lose contact like 1 hour in?

cpleppert 3y ago

They don't advertise any of their "new submersibles" on the website and the specifications they claim for Titan don't match any of their new submersibles; Titan is rated to go to the Titanic and not any lower. Titan isn't a previous version either. Unless they shelved the first Titan they probably just added some strengthening and called it a day. I'm blown away that for a sub of that size and shape they used carbon fiber. The sub is positively gigantic and a cylinder is very susceptible to failure after repeated cycles. I'm pretty sure the claims they made about working with NASA and having a system to monitor the structural integrity of the sub are just BS.

xarope 3y ago
"working with NASA"... "Hi Bob, did you used to work at NASA in the 60's? Can I ask, do you think this 1/100th scale submarine could get to this 1/100th scale titanic in my bathtub? kthxbye"
MagicMoonlight 3y ago
They found that their previous design with the same materials would get crushed at 2000m. And now this sub disappeared during descent…

rsynnott 3y ago

Based on the Wikipedia page, it _seems_ to be the same one? https://en.wikipedia.org/wiki/OceanGate,_Inc.#Titan_(4000_meters) https://en.wikipedia.org/wiki/OceanGate,_Inc.#Titan_(4000_me... It took a while to go from dismissing employee concerns to tourism, but it seems to be the same device.