Would the implosion have been loud enough?
I mean the thing was a tiny 7x3m cylinder located 700Km from the nearest coast...
I mean the thing was a tiny 7x3m cylinder located 700Km from the nearest coast...
Here's a naval study where they measured underwater sound propagation: https://www.navymarinespeciesmonitoring.us/files/7514/2780/4...
They found that a 10lb block of C4 exploding produced ~210db of underwater sound. If we use that sound level as an approximation of the implosion of 200 cubic meters of submersible, which seems not completely unreasonable, then we can use the inverse square law to calculate the perceived sound far away.
Halifax, NS is 1100km from the Titanic wreck. A sound that is 210db at 1 meter, is 89db at 1100000 meters. Boston is 1700km away; at that distance it would be 85db.
85db is really quite loud. You would be able to hear that, if you were underwater and paying attention.
If the implosion was instead, say, 180db, then it would have been 55db in Boston harbor. Still easily detectable by instruments.
For reference, when divers are performing construction using e.g. rock drills, those commonly reach 170db. The implosion of close to 200 cubic meters of air seems like it would produce a louder noise than a rock drill.
A former employee claims they were fired after brining up concerns about safety. The glass apparently was not rated for the depth required to see the titanic.
IMHO this was a get rich scheme the two founders spun up that went sideways. They spent the absolute minimum on safety and repeatedly cut corners on the sub in order to get it up and running, then charged people a ton of money to take a trip down deeper than the sub was clearly capable of going.
Perversely, a bunch of near-disasters can reduce people's concern and make them less likely to demand fixes because "it did that last time too and everything turned out okay" is a powerful rationalization.
Meanwhile, smart organizations have decades-ago stopped tracking (primarily) "Time-Lost Work Accidents" and replaced that with tracking "Close Calls".
I've seen prominent signs for "N Days Since a Time Lost Accident", and more recently "X Days Since a Close Call".
Sadly, it is so obvious that this CEO clown was doing everything possible to avoid experienced people ("not as inspiring to hire 50yo white guys as hiring young upstarts") so he could overrule any safety or redundancy concerns, firing people as soon as they raised things like "this porthole window is only rated to 1500m and we're going to 4000m", using cheap scrap scaffolding as ballast, and completely ignoring any kind of redundancy in case something went wrong. He seems to have gotten a just end, but his deceived customers didn't deserve that.
This problem extended far beyond this one individual, who was merely a symptom. The entire Birmingham maintenance facility, and perhaps British Airways more broadly, had a singular focus on “getting the job done.” If doing the work by the book took longer and jeopardized schedules, then doing the work by the book was discouraged. The shift manager who used the wrong bolts stated in an interview that if he sought out the instructions or used the official parts catalogue on every task, then he would never “get the job done,” as though this was a totally normal and reasonable attitude with which to approach aircraft maintenance. This attitude was in fact normalized on a high level by supervisors who rewarded the employees who most consistently kept planes on schedule. That a serious incident would result from such a culture was inevitable. The shift manager believed it to be reasonable to just “put on whatever bolts came off” and make a quick judgment call about what kind of bolts they were — not because he was personally deficient, but because he had been trained into a culture that didn’t consider this a flagrant safety violation.
In the absence of a proper means to report "That could have been bad" as you say it can cause normalization. But it's understandable that you don't implement something like ASRS when you haven't solved most of your "That was bad" problems. If you regularly have CI failures due to the code not even compiling, "We need more unit tests" isn't top of the list of your problems.
http://resource.npl.co.uk/acoustics/techguides/seaabsorption... -- here is a quick calculator for sound loss by distance. I think actual geography is important too but from understanding whether or not it's hypothetically possible, it certainly looks like it.
For example, at the default inputs we see .061 db/km absorption. This is at 1khz. Higher frequencies attenuated more and lower frequencies less.
I have no idea what frequencies an implosion generates, but given that, a sound at 120db might still be 60db 1000km later. Certainly seems possible and in fact given what we have seen from the US Navy (detecting imploding soviet subs in the middle of the pacific ocean) it seems totally possible to me that this small sub could be detected if microphones were places in quiet spots offshore of the continental US and Canada.
I think we don't have enough information to rule out that this was detectable.
Also, I wonder, if sound of explosions propagate that well, can one install multiple sensors to detect and map source of gunfire and artillery positions in realtime? (I hope I haven't disclosed NATO military secrets here).
Crossmatch that with the time of loss of communication and it's safe to assume that it's it.
Without any actual knowledge, I imagine that a ship or sub could be festooned with hydrophones, enabling it to detect faint noises, but also to determine their direction from phase information.
I would think another failure mode could be water rushing in without the overall structure catastrophically failing, which would actually relieve pressure on the structure as it happened and be much less energetic.
"The Spencer-built composite cylindrical hull either was repaired or replaced by Electroimpact and Janicki Industries in 2020 or 2021, prior to the first trips to Titanic."
Solid 5inch thick carbon composite OR a sandwich design with thick outer facesheets of carbon fiber? I suppose under that pressure not much would take the hydrostatic loads other than carbon, but that seems thick compared to everything I've seen made out of composites.
I think it was in Sub brief YouTube video. https://www.youtube.com/watch?v=4dka29FSZac&pp=ygUJc3ViIGJya...
https://www.compositesworld.com/articles/composite-submersib...
...since that article is from 2017, it is not clear that this was the unit that actually failed.
Not saying they are related at all but I am reminded of this:
Composite Overwrapped Pressure Vessels (COPVs) are fairly common in cases where a pressurized system needs to be relatively lightweight (e.g., spacecraft). To your point though, the failure mechanisms can be hard to model.
For a sub you have the opposite problem, which carbon fiber is very weak at.