1. First testimony is from Tony Nissen the chief engineer of the oceangate titan program
2. He mentioned that standards bodies and classification societies weren’t well involved and that the Titan met no such standard.
3. He mentioned that such classifications are very expensive, especially for a company looking to disrupt
4. He mentions that if we wanted to make driving 100% safe we could do that. But it would be wildly inconvenient for drivers. But we could, and we don’t.
5. Airplanes have rigorous classifications and safety standards, and still crash
6. There was a question about testing at the Deep Ocean Test Facility in Annapolis MD
   1. They claimed they wanted to do a hydrostatic test, but there were computers, and that the test facility had objections
   2. Stockton rush got irritated and scrapped the idea to do the test altogether.
7. 4-km data issues
   1. They did some testing measuring deflection in the hull at different depths. Then extrapolated the data to how it would look at 4km, which is 4000m or a little deeper than the titanic wreckage which is at 3,800m.
   2. They concluded that based on calculations the hull would be deflecting 37% more than expected, 
   3. Led Nissen to conclude: “We hadn’t really gone deep enough, long enough, and we were flexing 37 percent more, so it was,  it was the first warning.”
   4. Report was released Oct 2018
8. In april 2019, the vessel would dive to around 3700m with 4 crew onboard including rush.
   1. Spring 2019, they identify a crack in the hull during some pre-check.
   2. They identify that the outer diameter of the carbon fiber is covered in a soft rhino liner like material used in truck beds. To cover the carbon fiber
   3. On the inside there’s a HDPE (High density polyethylene) insert that is placed on the inside. This can be changed out based on application but hinders visual inspection of the carbon fiber.
   4. So Nissan flew out to the Bahamas confirmed there was a cracked and deemed the hull was scrapped and not to be used
   5. He was prodded if the following statement from Oceangate was a lie, stating that the expeditions in 2019 were canceled due to the loss of a support vessel. Which was a lie, since they didn’t have a submersible.
   6. Tony Nissen was fired shortly after in June 2019.
9. 1:28:00 – Composite vessel design spec was to last 1000 cycles at 6000m and 10000 cycles at 3000m, and the titan hull1  didn’t even last 3 cycles before developing a crack.
10. He mentions that Hull 1 was struck by lightning he believes, which might have been why it developed a crack. But its not 100% confirmed.
11. Then there is the viewport, made of acrylic.
    1. He mentioned that the viewport was only for 1300m not the 4000m needed.
    2. He mentions that acrylic is nice because it give clear signs of failure, with crazing (fine network of microvoids and fibrils) and crack growth.
    3. They had instruments to test, and it would require monitoring.
    4. Mentioned concerns of cold flow, or creep, which is slow deformation in a material that’s exposed to high stresses for a long period of time.
12. Interfaces!
    1. Nissen says “ things, things usually break  at interfaces, typically, because they don’t move together.”
    2.  There’s a famous saying that all of engineering happens at the interface. 
    3. Why are solid state batteries so hard? Handling ion transfer at the interface of the solid electrolyte.
    4. Nissen was asked about handling different moduli
       1. They’re talking about the modulus of elasticity. Which is the measure of the stress strain relationship.
       2. Stress / strain
       3. Two areas in question is the acrylic viewing port glass, compared to the titanium sphere, and the titanium sphere compared to the carbon fiber.
       4. Since delamination of the carbon fiber, and breakdown in unproven environments was a major concern, this is a huge part of the story
       5. Its not just stress strain modulus, what about thermal expansion?
          1. Temperatures could be in the 100’s when in direct sunlight before submerging
          2. And temperatures plummet in the depths, and all materials shrink and expand differently
          3. Thats how they install press fit things like this wheel bearing
       6. For ease of simulation and modelling they renoved the viewport in the titanium shell during simulations.
    5. They went away from grade 5 titanium to grade 3.
       1. Titanium is notoriously difficult to work with because it is so hard. That same property that makes it amazingly strong and light weight, also means its much more difficult to machine.
       2. Nissen claims that stockton rush made the decision to move from grade 5 to grad 3, to save months of time to procure and machine.
    6. Working on the frontier where standards aren’t established is hard
       1. They had acoustic sensors placed in the cockpit, that could detect if parts of the structure started to crack or buckle.
       2. Of course that only matters if you have enough time to take action and surface for example. 
    7. Nissen stressed that everything he could give testimony on only applied to serial 1 the first hull… not serial 2, and that much of the acoustic sensor detection software was rewritten and tweaked and beyond his purview.
    8. 2:00:22 – Final question would you get on the ship?
       1.  It’s why the word experimental is in, is in the waiver. Like I made them put that in there.
    9. 2:16:33 – metallic vs carbon fiber
       1. “A metallic doesn’t show you the same signature. Um, I’m actually not even sure that you could see acoustically a metallic break because metallic breaks are dislocations and you get atomic realignment when those dislocations move.

That’s how we get flexibility, um, in parts. So airplane wings stiffened because dislocation movement moves throughout that. But carbon fiber structures don’t. Once that snaps, It’s done. There’s no atomic structure next to it for the atoms to realign themselves,  really. The, even the glues kind of, kind of stiff, but the fibers themselves, once it, it snaps, it’s done.