23 ms·
Good video. Some excerpts: "If you're not breaking things, you're not innovating. If you're operating in a known environment as most submersible manufacturers
by bambax 3y ago
Good video. Some excerpts:
"If you're not breaking things, you're not innovating. If you're operating in a known environment as most submersible manufacturers do, they don't break things." (8:49)
"Our rule is we risk capital, we don't risk people." (9:56)
"We used the same prepreg that's used on the 787." (11:15)
And my favorite: "When you're outside the box, it's really hard to tell how far outside the box you really are." (8:30) He does seem to be far outside the box now.
But the most significant quote IMHO is the one about "the same prepreg that's used on the 787". Like they often tell you that phone holders for bikes are made of "aircraft-grade aluminium" (which usually means it's 6061, the most common alloy). It's a strong indication of bullshit -- name dropping that doesn't have anything to do with the subject matter.
In the rest of the presentation he seems nice enough, and truly passionate about deep sea exploration. So maybe he was a cool guy, I don't know. But in the end it's his hubris that killed him and his clients.
- deleted 3y ago[deleted]
- oasisbob 3y ago> name dropping that doesn't have anything to do with the subject matter This is a good point. However, it's probably worth pointing out that in the past few decades -- at least here in the PNW -- carbon fiber availability to the hobbiest and small producer has been spotty. I'd refer to Boeing and being the same 787 carbon fiber for my personal projects, but that's just because they're made from Boeing offcuts donated to a local University. At the time (ca 2006), even bare weave was hard to obtain from private suppliers. Its feasible that Rush may have had help from Boeing sourcing his material, which puts comments like that in a different light.
- gamblor956 3y agoAircraft grade aluminum is 2024 or 7075, not 6061, because those alloys are more resistant to fatigue from repeated pressurization cycles. 6061 is more commonly used in automotives than in aircraft.
- cowmoo728 3y agothe comment above you is correct that consumer goods will often brag about "aircraft grade" when referring to 6061. like flashlights, tools, combs, pens, cufflinks, money clips, etc.
- Kailhus 3y agoThis made me realise how little I know about alumiunium and made me summarise this from a quick wiki search: - “2024 aluminium alloy is an aluminium alloy, with copper as the primary alloying element. It is used in applications requiring high strength to weight ratio, as well as good fatigue resistance. It is weldable only through friction welding, and has average machinability. - “7075 aluminium alloy is an aluminium alloy with zinc as the primary alloying element. It has excellent mechanical properties and exhibits good ductility, high strength, toughness, and good resistance to fatigue. It is more susceptible to embrittlement than many other aluminium alloys because of microsegregation, but has significantly better corrosion resistance than the alloys from the 2000 series.” - “6061 is a precipitation-hardened aluminium alloy, containing magnesium and silicon as its major alloying elements. It has good mechanical properties, exhibits good weldability, and is very commonly extruded. It is one of the most common alloys of aluminium for general-purpose us.”
- jacquesm 3y agoThere are 8 basic alloys of aluminum based on the alloying element(s) (or none for 1000, which is pure) with the 8000 serving as a sort of catch-all for various combinations that don't warrant a category all their own. The total number of formulations is quite large and the properties, machinability, weldability, various strengths, density, resistance to fatigue (and post processing options, such as hardening) vary considerably. Materials science is a fascinating field.
- carabiner 3y ago> It's a strong indication of bullshit -- name dropping that doesn't have anything to do with the subject matter It means you're using a material that's been vetted over decades in life-critical applications in harsh conditions by expert engineers all over the world. Aerospace aluminums today are derived from Japanese alloys invented in WW2 and were a major innovation in metal aircraft. It's much more expensive than steel, but we use it because of favorable characteristics. Here's an overview of different aluminums and where they're used: https://www.aircraftaluminium.com/blog https://www.aircraftaluminium.com/blog
- gregors 3y agothis wasn't an aircraft
- buffington 3y agoThe reference to "aircraft" wasn't about airplanes or submersibles, it was about how the term "aircraft-grade" is a meaningless marketing buzzword. It's obvious to me, and I imagine a lot of readers, that a submarine isn't an aircraft. I think the reference to the use of the bullshit marketing term is also obvious.
- rightbyte 3y ago"Military grade" is another one of those marketing phrases that pisses me off. What does it even mean? That it is green and is more expensive than it should be?
- hef19898 3y agoThere are some compabies that actually do test theor products according to military standards. Now, ideally they would tell you which ones. Whether or not those standards are better than theor civilain counterparts is a different story.
- buffington 3y agoI think I read a comment on HN that described what "military grade" meant: stuff made as cheaply as possible by the lowest bidding contractor that sometimes is fit for purpose. That said, I think there are times when it does mean something. I believe military grade/milspec chips/ICs are often engineered to be more resilient to environmental factors like heat and vibration, interference, etc. If I'm wrong about that, I suspect it won't be long before we learn if I'm right.
- gregors 3y agoNow might be a good time to revisit the "calling yourself an engineer" means something specifically debate.
- bombcar 3y agoI’ve seen it said you’re not an engineer unless your job and/or life is on the line, under which standard he’d qualify.
- mc32 3y agoThe question are: Why use novel vessels when tried and true work. Why did they have to try a carbon-fiber wrapped vessel? The bathysphere went all the way down to the Marianas trench --many decades ago. Why try something new in unforgiving environments? Why fire an engineer after he started raising questions about safety? It seems like there was a bit of a cavalier attitude that cost five people their lives.
- perihelions 3y agoI don't believe that one was particularly safe in its design either? Just quoting the most colorful parts of Wikipedia's history: - "Oxygen was supplied from high-pressure cylinders carried inside the sphere, while pans of soda lime [hn: sodium hydroxide?] and calcium chloride were mounted inside the sphere's walls to absorb exhaled CO2 and moisture.[6] Air was to be circulated past these trays by the Bathysphere's occupants using palm-leaf fans.[2]" - "Suddenly, without the slightest warning, the bolt was torn from our hands, and the mass of heavy metal shot across the deck like the shell from a gun. The trajectory was almost straight, and the brass bolt hurtled into the steel winch thirty feet [9.1 m] away across the deck and sheared a half-inch [13 mm] notch gouged out by the harder metal. This was followed by a solid cylinder of water, which slackened after a while into a cataract, pouring out the hole in the door, some air mingled with the water, looking like hot steam, instead of compressed air shooting through ice-cold water.[6]" - "The ocean during this dive was rougher than it had been during any of their previous dives, and as the Freedom rocked on the surface, its motion was transmitted down the steel cable, causing the Bathysphere to swing from side to side like a pendulum. As the Bathysphere descended, Barton succumbed to seasickness and vomited inside it. However, the first half of the radio transmission had already been broadcast, and neither Beebe nor Barton wished to cancel its second half, so they continued their descent.[5] ... the Bathysphere was still rocking wildly and Beebe and Barton were both bruised and bleeding from being knocked about inside it." - "During their first test dive, they demanded to be pulled up after descending only four feet (1.2 m) because the sphere had begun to leak; they soon discovered this was because Tee-Van had neglected to fasten all of the bolts that hold the hatch shut.[2] Another problem occurred on their second test dive, during which they discovered that the lower end of the rubber hose holding the power cable and phone line had begun to deteriorate, and they spent the rest of the day reversing the hose's direction so that the end which was deteriorating would be the end above the water.[5]" https://en.wikipedia.org/wiki/Bathysphere https://en.wikipedia.org/wiki/Bathysphere
- frakkingcylons 3y ago> He does seem to be far outside the box now. Very poor taste to say this now.
- hef19898 3y agoThe 787 preprec is actually pretty good. At holding a pressure delta <1 bar on the inside...