[jonathanstrange]

This is not true, the maker of this sub compromised substantially on safety and did not have it certified by an independent body like most other builders of deep sea submarines do. In fact, members of the small deep sea submarine community wrote a letter to the company warning them about the safety hazards and the lack of certification. Source: Today's interview with a deep sea exploration submarine commander on German TV (ARD Tagesschau).

In particular, this company used carbon fiber materials that were neither tested nor certified for the intended operational depth, and they also did not do extensive testing like you do when you certify a craft.

[gambiting]

As it's explained in another comment - the CEO wanted it tested but there isn't a facility anywhere on earth equipped to test it. Perhaps the argument then is that part of the company funding should have been building a custom rig designed for testing this highly custom 5 inch thick carbon fibre shell - but it's not like options to test it were available and were ignored.

[jonathanstrange]

This is not true either. As the submarine commander interviewed lays out, the testing is done by actual dives, and there is a certification body for it. Almost every other deep sea exploration submarine is certified. However, getting certified is voluntary.

Of course, certifying it just means that independent experts take a look at the design and use sensors during dives. All of these vehicles are experimental. But not even trying is negligent.

[hef19898]

It is almost like there are already deep sea subs in existence. And that people already figures out how to test, and certify, them.

[zirgs]

I suspect that certification is not going to be voluntary any more after this.

[lelanthran]

> the CEO wanted it tested but there isn't a facility anywhere on earth equipped to test it.

They could have dropped it to the bottom of the sea with weights, have a timer release the weights and hauled it back up. Cheaper than renting any testing facility on earth.

They could have done this multiple times on the same hull until it imploded. If a month of dropping it and retrieving it doesn't result in implosion, then it's probably safe enough to put people into it.

There was no need to make its first test of that pressure with people in it.

[robertlagrant]

The answer to "this can't be tested" isn't "don't test it". It's "don't use it".

[gambiting]

A lot of things that we use all the time couldn't be reasonably tested in operational scenario in any other way than by just using them(most planes are in that category - you can test a lot of things on test benches but there isn't a way to test an airliner at operational speed an altitude other than actually flying it)

[robertlagrant]

I think if SpaceX can send 15 robotic rockets into space to test them, this lot could've sunk a prototype to high pressure and got a diver to go down and smack the hull with a wrench for a while.

[HeyLaughingBoy]

Actually, it's "don't design it in a manner that will be untestable."