If you had to design a glass submarine that was able to to survive all the pressure at the bottom of the Mariana

Question: If you had to design a glass submarine that was able to to survive all the pressure at the bottom of the Mariana Trench, how thick would you make the glass and why?
- Keywords:
  design,
  submarine
Asked by SPT :) to Carson on 10 Nov 2017.
- Carson Vogt answered on 10 Nov 2017:
  
  Ooo, ok, that’s an interesting question. I don’t know off the top of my head, and I don’t know if you’re interested in working it out, but we can get a basic idea maybe :/
  
  According to google, the pressure on the bottom of the Mariana Trench is 108600 kPa.
  
  One atmosphere is 101.325 kPa
  
  The pressure differential then is ~108498 kPa
  
  Now then, the most crucial part is going to be the shape of the submarine. I know from working with planes, which have a higher pressure inside than outside, that pressure and angles don’t work well together, so the ideal shape for a sub would theoretically be a sphere.
  
  Sooo, I’m gonna stop there, because I checked around to validate my theory that a sphere would be the best structure, but it turns out glass has some interesting molecular properties under pressure that I’m not familiar with. SO, apparently the answer is 10-15 cm, but that is from this article I found regarding the sphere at depth http://www.bbc.com/future/story/20141205-glass-sub-for-the-deepest-depths. It’s an interesting read, and will do a better job explaining than myself. 🙂

Question: If you had to design a glass submarine that was able to to survive all the pressure at the bottom of the Mariana Trench, how thick would you make the glass and why?