Typically it is ultrasound, or X-ray CT. It does become difficult to do with large pieces and/or thick sections, but I don’t know if this hull was too large. However, if the manufacturing process were qualified using smaller pieces that were testable with NDE/DE or a full size piece that was DE, that would generally be acceptable for the large component.
I am a materials scientist working in another highly, highly regulated field, and part of my job is working on how to accelerate materials discovery and qualification for next-gen technology. Part of that means working with codes and standards bodies and regulatory agencies to get their acceptance in the new tech. It’s going to take some time, but it’s worth it.
Thus, the Titan story touches a particular nerve for me.
This entire tragedy could have been avoided if codes and standards were followed. The 2018 whistleblower was concerned about flaws in the carbon fiber composite that could grow and cause implosion failure after repeated pressure cycling. It looks like this is exactly what happened.
Let me point out that the pressure at 4000m is about 100 MPa: that’s above or near the yield strength of many common alloys. It’s a lot. Let me also point out that carbon fiber composite doesn’t yield, it just fails catastrophically, and also let me point out the idea of Weibull statistics, which look at the variation of things like yield and ultimate strength for brittle materials - there is generally a large range of measured strength based on the internal flaw structure of a component. Whistleblower asked for non destructive examination of the material to understand its flaw structure: an extremely usual request and generally something that everyone is on board with doing. Why not here?
Multiple people raised concerns about the safety of this sub. Rush ignored them all, or refuted them all with BS arguments. He said they didn’t need to qualify the sub because commercial subs were so safe over the last 35 years that it’s just human error these days, ignoring that the reason subs are safe is BECAUSE they are qualified, leaving ONLY human error as a problem source! It’s like saying “I don’t need to vaccinate against measles because no one catches measles anymore”… Because everyone is vaccinated against measles! But look what happens when vax rates drop: we get measles case clusters.
Regulations are written in blood, and this was ignored by Rush. The first thing drilled in to you in engineering school is that you must protect the safety of the people you are engineering for. Rush abandoned this principle out of greed and hubris. And now a teenage boy is dead who didn’t even want to go on this trip. It sickens me.
There is a cohort of women (biological) who are very in favor of sex-separated bathrooms. Women are vulnerable to sexual assault when having to take care of bodily functions and have the unique risk of being impregnated from said assault. This article discussed issues with public toilet access and usage for women in India, for example. If a group of women in fact want sex-separated bathrooms, then I think logically that should win out over those who don’t care. Men’s bathrooms should also be safe for gender non conforming people and could in fact be the default bathroom for everyone.