DSV Alvin : How to build a safe submersible

[@Alexander-the-ok]

Ok, as always, here are the clarifications and corrections: > it turns out it’s pretty common for electron beam welds to be stronger than the base material for complicated materials science reasons that I don’t fully understand. > When I said ‘titanium is easy to forge’, that was a huge oversimplification! It’s malleable but a ton of specialised processes are necessary to ensure a good quality forge. > ‘High frequency sound travels further in water’ is also a massive oversimplification. It’s actually attenuated more than lower frequencies. But can carry more information. Underwater telephones shift to a frequency that is a compromise between the two: which happens to be a shift upwards from human speech.

[@tigerchills2079]

As a ham radio operator I'd wish to know more about the underwater telephone. The first time I heard about it, I thought it was just converting the audio signal to an amplitude modulated radio signal with no carrier frequency. I believe for that you don't need much more than a microphone, a good amplifier and a very long cable or coil as an antenna. The detector is almost the same in reverse: a big coil, an amplifier and a speaker. If you want to make it really simple, you can even use the speaker as an inductive microphone and a flip switch to switch between reception and transmission. Anyway, that's my theory so far. But it's hard to imagine that they used no carry frequency, as I believe you could have gotten disturbances from the machine room on such low frequencies - even from mechanical systems.

[@Alexander-the-ok]

@@tigerchills2079I can never get my head around ham radio stuff, but my first thoughts were exactly the same as yours. Turns out it uses USB modulation but via sound waves instead if EM waves. Exactly how that works, and the physical mechanism for it, I’m not smart enough to understand.

[@tigerchills2079]

@@Alexander-the-ok Ah, that's interesting. Upper Side Band, that's half of an amplitude modulated signal, which otherwise is a symmetrical signal around the carrier frequency. So, it's sound waves and no radio waves. Alright, that means they actually use pressure waves in the water to transmit the signal to the next vessel. I guess that could be called a transducer. Maybe submarine/submersible comm's expert can fill in the blanks, but thank you for sharing what you got on the topic

[@jbca]

How is “high frequency doesn’t travel further, it’s attenuated and travels less far” NOT a correction?

[@extantsanity]

@@tigerchills2079 Which makes it all the more laughable that the Titan submersible was touted as being the iPhone of underwater exploration when they're all but relying on Morse code for communication. What a complete jackass.

[@SloMoMonday]

My first thought was "they really thought of everything". Then I realized that everything and more is the bare minimum. Every redundant system, override, tool and component is built to provide passengers with the best possible chance of coming home. And the constant revision, updates and even the fault found during certification just highlights that it's nowhere near perfect. Safety in the face of such risk requires constant vigilance and I'm glad you're spotlighting this incredible work.

[@RossM3838]

Alvin has not been without problems. With each problem the Alvin has been improved to deal with it. Over 60 years and thousands of dives the managers of the Alvin have learned a lot and have denied nothing.

[@TheGallantDrake]

@ko7577all the cash in the world can’t stop a man from saying “looks good to me” and pocketing the remainder. Money can’t buy integrity.

[@PaulWood-r7c]

@ko7577 It requires thinking about everything and then raising the cash to do it. If you don't have the cash, whether through VC or your own money, don't bother.

[@Mordecrox]

As NASA once said, "quadruple failure that isn't supposed to be possible", after it was proven it is possible, and happening right now, suddenly quadruple redundancy isn't good enough even for ground operations.

[@wickedcabinboy]

@ko7577 - "But anyway, yeah, safety costs money." An incredibly simplified summary, but not inaccurate. Which is precisely why Titan suffered a catastrophic failure with the loss of all souls on board. To state the obvious, Rush's very public aversion to certification was motivated by his desire to construct and run his DSV on the cheap. He just used educated jargon, hand waving and abysmal judgement to pursue that desire.

[@jonathansnow1886]

I dove 6 times in DSV Shinkai 6500 in the last 20 years, most of the dives deeper than the Titanic. This is an excellent discussion. of the design principles that were explained to me over the years. Thanks!

[@Alexander-the-ok]

What an amazing experience, I’m so jealous. The Shinkai is a wonderful craft. Unfortunately it’s a difficult one to research - I wish I could speak japanese!

[@brunonikodemski2420]

Along with the precursor to the Alvin, the DOWB, from General Motors Defense Research Labs. I worked on it, and designed equipment for it.

[@worawatli8952]

I've seen some video, it looks like the floor and seat cushions are thicker than any other crafts, must be a comfortable ride.

[@cookie5535]

@@brunonikodemski2420whats ur position on the project what did you work on?

[@stekra3159]

This is great How was it down ther?

[@Daniel-yy5tx]

I remember as a kid I read about Alvin's last-resort escape mode that ejected the pressure sphere but left a huge amount of expensive hardware behind, so it's interesting to hear that it's been superseded by having the most entanglible (and much smaller and cheaper) components break off instead. Now THAT'S innovation!

[@oblivion_2852]

The biggest buoyancy aspects are probably the steel weights and the droppable batteries. The thruster dropoffs would only be useful in case of entanglement

[@Daniel-yy5tx]

@@oblivion_2852 For sure! But the last-resort was also meant to be used if Alvin was hopelessly entangled with something on the seafloor, meaning that theoretically a single fishing net could cause the loss of everything except the pressure sphere. Now it just means the loss of much smaller, much cheaper components.

[@Hamdad]

To be honest the crew sphere separation function was really cool, even if it was suboptimal, and part of me is sad to see it go

[@tigerchills2079]

I like how we suddenly have so many submarine experts on youtube. I'll collect those vids in a playlist and then I build my own submarine over the course of the next three years. Ticket selling will start soon, so you better be quick

[@fuckoff4705]

i do hope you'll make it nice and cheap so its accessible to small fortune billionaires like me, maybe try composite hulls?

[@alaeriia01]

​@@fuckoff4705I was thinking of a hull made out of papier-maché.

[@benjaminrogers9848]

He could buy the composite second hand so that its accessible to us millionaires too!

[@alaeriia01]

@@benjaminrogers9848 ooh, good call. What are we going to do about controlling it, though? All I got is this shitty Logitech controller.

[@benjaminrogers9848]

What the heck, let's throw it in for the memes

[@mephisto8101]

I am pleasantly surprised by the quality of your presentation. The difference between Alvin and Titan in respect to design, testing and underlying mindset is simply astonishing.

[@Keiranful]

Yeah, that's how a bunch of "old white men" design a DSV. Honestly, I don't buy the line about wanting to inspire young people. That sounded like corporate fluff to hide an unpalatable truth. He was either to cheap to use experienced personnel or knew that he couldn't bully them like he did with his entry level engineers. What really makes me angry is that his stupidity/egomania killed four other people and left a professional black mark on the engineers he hired "to inspire", as well as the psychological burden of knowing that their inexperience/negligence contributed to the disaster. If it had just been him on the sub, I'd say it couldn't have happened to a nicer person.

[@Alexander-the-ok]

Thanks. Yeah, the two aren’t even comparable

[@ronansmith9148]

Titan was meant to bring people down to titanic, Alvin was designed to get people back.

[@Raptor747]

Yeah, the bottom of the ocean is one of the most extreme environments we can actually reach with people (and have any hope of surviving/returning); even space is way less extreme (though has the additional danger of having basically zero prospect for rescue) in most respects. But because deep-sea diving has the benefit of having relative safety a handful of kilometers (or less) away, it allows for all sorts of brilliant ways to increase safety through excellent engineering and design. Alvin shows so many smart methods/approaches this regard that it's an undeniable testament to the designers' prioritization of safety and reliability.

[@redion8575]

25:20 The submersible knows where it is at all times. It knows this because it knows where it isn't. By subtracting where it is from where it isn't, Or where it isn't from where it is (whichever is Greater), it obtains a difference, or deviation.

[@zwickflixproductions4379]

And arriving at a position, it now is.

[@TheVeganarchism]

This feels like a reference to The Hitchhiker’s Guide… 😂

[@snark894]

@@TheVeganarchism it's a reference to a (bad) explanation of a missile guidance system from around the mid 20th century

[@vicroc4]

​@@snark894It's not so much "bad" as it is "unnecessarily long-winded and convoluted." The description itself is accurate enough, but they used way too many words to say something that could be made a lot simpler.

[@judet2992]

@@TheVeganarchismit is most assumably not

[@bensonboys6609]

It’s so interesting how the close call was the cable breaking when the hatch was open. A dangerous situation while being completely unrelated to pressure or being stranded underwater. It’s a good reminder that there exist dangerous instances and failure modes that you haven’t thought of. Obvious in hindsight, but I would have never thought of it.

[@harkonen1000000]

For the ping-pong ball, you could use a watchmaker's water resistance testing chamber. The ones that go to 6 bar are near-ubiquitous in the business.

[@Alexander-the-ok]

Thanks. Yeah that was just a quick ‘throw it together for a 10 second video segment’ but a lot of commenters seem interested. I may revisit it in the future.

[@AndyAz]

A soda bottle holds pressure quite well up to 2-3 bar, but I wouldn't stand near it during the test.

[@superslimanoniem4712]

Also I'm fairly sure a lot of ping-pong balls aren't ABS but rather nitrocellulose.

[@MattOGormanSmith]

@@AndyAz How would you get the ball inside? I guess there are jars and bottles with larger lids but they probably can't take so much pressure.

[@garethbaus5471]

​@@MattOGormanSmith In my childhood testing Gatorade bottles can reach slightly higher pressures than most other soft drink bottles although it will noticeably deform pretty quickly.

[@kylewhite5695]

I’m a simple man, seeing bad engineering makes me sad, seeing good engineering makes me happy. You made me happy today

[@ladywaffle2210]

You can *hear* how happy he is to talk about an actually good submersible in his voice. It's adorable.

[@eamonia]

...and we can hear your furry balls scratching up against your skirt. 😂

[@TheGodpharma]

There's a couple of extra things I'd like to know: 1. How the entry hatch was designed and how it works, and 2. How are inputs into the steering thrusters, as well as data from external sensors etc transmitted between the pressure hull and the external components? Assuming it isn't wireless, where do cables run through the pressure hull and how are those entry points sealed?

[@noksucowboy]

A hull penetrator is used-have a Google, bit technical to explain here

[@phillyphakename1255]

​@@noksucowboydoes Google autocorrect to hole penetrator? Seems like a risky google...

[@noksucowboy]

@@phillyphakename1255 as long as you don't act on it, you'll be fine

[@seymourpro6097]

When Jacques Cousteau created his submersible he had two hulls made and tested then he sank one deliberately, on an anchor and cable, in a very deep part of the Med. Every voyage out for a deep exploration he went over the sunk craft to check on sonar that it was still floating it's cable length above the sea bottom. If the sunk hull failed and sank to the bottom then the working hull was scrap. Sadly Cousteau was largely of the pre KZbin era, BUT several people have posted film of Cousteau's exploits and Jacques Piccard's journeys.

[@davidpawson7393]

Funny story: My father and Al Gore presented Jacques with his lifetime achievement award but my father had given my sister and me a quick golf lesson up at our elementary school where I got laid flat by a golf ball hitting my forehead, no biggie, and my sister then splits my dad's forehead with an iron which obviously needed stitches but no time for that. Al's makeup crew saved the day by using superglue and an extra shirt as it wouldn't stop bleeding. Not really an Al fan but Jacques most definitely as I am of my father.

[@Kenionatus]

Hm. That doesn't seem like the best proxy. It doesn't account for cumulative damage and has different corrosion to being in a probably pretty consistent environment. A better proxy would be a second sphere that does a similar dive profile to the crewed sub but a decent bit deeper each time, so it has a high chance to succumbing to accumulated damage first.

[@josephmckenney-barschall864]

It occurs to me that the reason the ping pong ball didn't buckle at the expected pressure has to do with the fact that it is full of air at likely slightly more than one atmosphere. As it begins to buckle, the internal volume decreases, and the internal pressure increases.

[@brunonikodemski2420]

Ping Pong balls do buckle, at any internal pressure. This is a mechanical asymmetry issue, also valid in any pressure applications. When we were modeling the DOWB, it was obvious that the symmetry is vital. As a result, much of the steel body was actually machined away (both sides), to make as much equality as practical (based on empirical data and testing of small-scale thinner models). This was also true of nuclear weapons "cores", where the pressure was externally applied. See books by Rhodes, about how they did this for nukes.

[@mister-nonchalant8249]

​@@brunonikodemski2420⁶⁶66😅😅

[@qwasd0r]

DSV Alvin has a fascinating history involving super-secret cold war operations, a sunken hydrogen bomb, and more.

[@brunonikodemski2420]

Along with the precursor to the Alvin, the DOWB, from General Motors Defense Research Labs. I worked on it, and designed equipment for it.

[@jamesgroccia644]

From an undercover ballistic missile sub operation to the most famous shipwreck in modern history, Alvin's had quite a wild ride - but thankfully that ride was implosionless.

[@veramae4098]

"EV Nautilus" does great yt deep sea research. The researchers are on the SURFACE ship. The rest is all remote hardware. My favorite episode has to be the one when a sperm whale slowly swam out of the dark, unexpected, and did quite a lot of looking over the ROV.

[@michaelimbesi2314]

Yankee here. Thanks for doing the calcs in SI. I work in SI whenever possible because it's easier and also I can never remember the density of steel or seawater in US units. (Also, the nearly the entire US shipbuilding industry is metric now anyway.)

[@Alexander-the-ok]

Thanks. Ironically, the UK is still stuck in a ridiculous ‘inbetween’ where imperial units crop up all over the place. They are very rare in industry though (with some exceptions).

[@judet2992]

Oh, glad we’ve stopped using Freedom Units, they’re much more archaic.

[@supertinheng]

As a US civil engineer, I'm still plagued with imperial units; we even use a hilarious unit called a Kip, which is 1000 pounds (kip = kilo-pound). Steel is 490 pounds per cubic foot Reinforced concrete is 150 pcf Water is 62.4 pcf Saltwater is 65 pcf Could be worse. In college we measured hydrostatic force in slugs.

[@BrooksMoses]

@@supertinheng : ...wait. Hydrostatic *force* in *slugs*? But a slug is a unit of mass! A unit of mass that you only use because you were using pounds force and wanted the porportional constant in f=ma to be equal to one. What kind of poor life choices does a field make to get to a point of measuring force in slugs? That sounds deeply painful, and makes pounds-force and pounds-mass sound sensible.

[@el_puma_real]

The Alvin sub is one of the only subs I’d even consider traveling to the sea bed in. I’d feel safe because literal science and math went into every single aspect of the craft. Great in-depth (no pun intended) video 👏🏽

[@jameson1239]

To be fair almost all Deep sea subs have gone through the same certification process as Alvin

[@Alexander-the-ok]

I’d go in any of the current operational DSVs. They are all similarly built and certified

[@AhmedKhan-qk3xi]

You should prefer the Limiting Factor

[@Taygetea]

@@AhmedKhan-qk3xi only slightly though, unless youre in water deeper than alvin can handle of course

[@Hamdad]

@@AhmedKhan-qk3xi papa Gaben's sub is the most based, for sure. Also the only 2 seater full ocean depth dsv anyway, so the only option unless he's a certified sub pilot himself

[@icebluecuda1]

Thank you. As a former engineer turned pilot, it is nice to see quality fundamental analysis and discussion. Honestly I could watch hours of content like this.

[@Alexander-the-ok]

Thanks, there is more on the way.

[@ellenbryn]

I can't believe Alvin is still going. I remember the incredible excitement in the scientific community in the 70s, articles in National Geographic and Scientific American, when an Alvin expedition discovered "black smokers"' on a spreading ridge, hydrothermal vents surrounded by life. It was a huge discovery, because it suggested an alternative food chain dependent on heat and chemicals from a planet's interior rather than sunlight - a much safer way for life to develop before photosynthesis built Earth's oxygen atmosphere and ozone layer, and a possibility for life in the ice-crusted oceans of Jupiter's and Saturn's larger moons.

[@tuunaes]

Basically it's been rebuilt many times and only part left from original is name.

[@SVD_NL]

When i first saw the Titan sub using a video game controller, i didn't think of it as a huge deal (except for the wireless part of course, USB uses serial communication and can be used with very few points of failure with a bit of work). Now after seeing the cockpit of this submarine.... its basically the difference between a Tesla and a Boeing 747.

[@christopherjones7191]

It still surprises me how titan looks like baby's first DIY sub vs what Alvin looks like.

[@zactron1997]

Excellent video! I only did a couple of semesters worth of Civil and Mechanical engineering before heading off to my own specialization, so this was an excellent refresher/clarification of some of the subjects I haven't touched in years!

[@Alexander-the-ok]

Thanks. I hadn't even thought about shell buckling for at least 7 years before this so that part gave me some flashbacks

[@ryancraig2795]

Yeah I don't remember a lot from my strengths of materials courses, but I do remember that compared to simple tension or compression, buckling modes of failure were many and complicated.

[@AJMansfield1]

27:00 Laser ring gyroscopes are _astonishingly_ precise devices. You know how an airliner's navigation computer gets its initial position information after a reboot? It uses the laser gyroscope to _measure tiny wobbles and tidal forces affecting the earth's rotation_ and uses _that_ to work out a position fix. GPS and other navaids get incorporated too, if available, to allow the inertial platform to converge on a fix faster, and they're used to correct for positional drift that begins to accumulate once the plane leaves the ground. But the inertial reference platform is the main instrument in charge; everything else is just drift correction and redundancy.

[@AJMansfield1]

Also, given that it's owned by the navy, I'd be willing to bet that it's fitted with essentially the same inertial navigation package as the rest of the submarine fleet. The exact performance of that system is shrouded in mystery (i.e. it's classified), but from what we do know, it's orders of magnitude more precise again than the systems used on airliners and can go for _months_ with no external navaids without accumulating more than a few meters of drift.

[@Alexander-the-ok]

My thoughts exactly. I thought that gyro seemed like overkill until I remembered it's a Navy vessel!

[@allangibson8494]

@@AJMansfield1The system isn’t exactly secret - it’s a SEADeViL INS system (and the Alvin’s companion ROV Jason II has the same system). The military secret squirrel stuff is the magnetic and gravitational anomaly detection systems that let the attack submarines see surface ships and submarines without using active sonar.

[@theq4602]

laser ring gyroscopes were developed to orientate the hypersonic anti ballistic missile called sprint in the 1970s

[@IDWpresents]

The thing that really brought home how fantastic Alvin is to me was the ping pong ball section. You did a really good job of showing how hard it is to predict that sort of thing and I was amazed that the Alvin people just got all of their simulations to work perfectly on the first time.

[@brunonikodemski2420]

We built the DOWB for naval use, at about the same time as the Alvin. It used a steel sphere, which did not have the corrosion problems of aluminum. However, iron is way heavier, so the aluminum constructions became more standard, even if they required more safety measures. The DOWB was essentially a clone of the NR1 secret naval submarine, of the working arms and tooling fixtures. This technology was later used on virtually all of the oil platform tooling submersibles. We did one tooling fixture for Exxon that was used down to 4000 feet, and the DOWB was certified to 6000 feet. Exxon did a lot of deep drillling using our systems, to find oil layers, down below 14000 feet, in all sorts of ocean areas. They have a database of the entire Earth.

[@637man3]

One of my favourite parts was at 19:28- the production document for Alvin's sphere- where four years of intensive work are condensed onto a single page. The NAVSEA and ABS certification was interesting; Thresher was certainly an example of why the SUBSAFE program became the cornerstone of American submarine construction. Thank you for the post, it was absolutely engrossing. (edit: clarity)

[@AGryphonTamer]

Every once in a while I stumble across a reason to think about the pressures deep underwater, and every time it boggles my mind anew.

[@Skyhawk1998]

Seeing this and the documentary on the Limiting Factor's construction has been fascinating. It is also been incredibly frustrating. Four essentially innocent bystanders lost their lives because one man thought he was above best practice and did not need to be cautious. The entire process for building and testing a safe submersible is well known but he chose to completely ignore it.

[@Alexander-the-ok]

You've just reminded me, I forgot to add that to the sources list! That is a great documentary.

[@ChadDidNothingWrong]

That's a bad attitude to have. Don't ever convince yourself that your safety and judgement is somebody else's responsibility. Especially don't teach your kids that if you give the slightest care about them

[@brianwelch1579]

@@ChadDidNothingWrong You're absolutely right. So, before you go out and drive or walk on streets, be sure to complete your own safety certification on that truck that's careening your way. It's OK though, the trucking company says they have perfect safety and maintenance records! Do you do your own brake jobs?

[@allangibson8494]

@@brianwelch1579No but it is perfectly reasonable to assume that the typical vehicle on the street is operated by an inattentive idiot - and not stand in front of it.

[@Skyhawk1998]

@@ChadDidNothingWrong Unfortunately a lot of people do not have the technical knowledge to properly judge if something is safe or not. Someone who doesn't even change the oil in their own car is unlikely to seek out technical information on whether that car was designed well and even less likely to be able to comprehend it.

[@Taletad]

Oh my god 40 min on DSV design ? YES PLEASE !

[@thomaskositzki9424]

Ahhh, so wholesome to see something done RIGHT instead of cobbled together. Calm seas and following waves, Alvin!

[@dainchi.]

That was a surprisingly insightful presentation on a topic I didnt even know i'm interested in. Excellent work!

[@losbexp]

This is one of the most in-depth analysis on a DSV I've ever seen. Thanks, mate.

[@JulianHalliday]

Wow. This is an eloquent, fascinating trip into a world of engineerin which I -- a technical writer -- had only glimpsed before. Thank you for such a gripping and detailed video. It reminds me once more that risk assessment -- and probability and statistics -- are really essential, and underrated, components of an informed approach to the world.

[@guard13007]

"[...] certification often feels like an extremely expensive tick box exercise [...]" My immediate reaction to this: Because it is, and it needs to be done, and that's why you do it. Those boxes NEED to be ticked. While obviously a very very different level of stress/danger, this is how I think about packing for a trip. I have a massive checklist, but I never forget anything I need because of it. It is expensive in terms of mental effort and time, but it is more than worth it in preventing even more expensive issues from not having packed everything I need.

[@TheLoneWolfling]

Yep, 99% of it is 'are you _sure_ you remembered your toothbrush', and then the other 1% is 'whoops I _did_ forget my toothbrush' - only instead of an inconvenience it's death.

[@InXLsisDeo]

​​@@TheLoneWolflingorse than the toothbrush, leaving your passport in the safe of the hotel room is a massive mistake. I always made a point of checking everything before leaving, until that one time I forgot to check the safe... there is a reason why checklists exist.

[@claudevillee5446]

In your list of other Alvin incidents, you forgot to mention the incident with the swordfish. It goes to show that danger can come in surprising forms. Also, while I know that Alvin was not seriously damaged by the swordfish, I wonder what sort of damage Alvin did sustain. Excellent video, very informative. Growing up, I would sail with my parents out of Woods Hole harbor and it was always a great day when Alvin and Lulu were in port.

[@Alexander-the-ok]

I resisted discussing the swordfish as it’s a pretty well told story at this point

[@xenuno]

Don't have to worry about swordfish much anymore. Humans have done a good job of near sterilizing the oceans with the over fishing that goes on ..

[@gregmead2967]

While a lot of this is over my head, I want to express my thanks for this detailed description. I'm a geological oceanographer, and although my particular area doesn't need Alvin, I know quite a few people who've been on dives, in some cases many dives, and this video really brings home how demanding the environment is.

[@dschortz]

Excellent video! I’m glad that discovery and history channels got out of the way for STEM KZbin to thrive. Loved the FEA, graphs and ping pong ball demonstration. Learned a lot!

[@ctrlaltdebug]

You mean Ice Road Trucker and Ancient Aliens channels.

[@measlyfurball37]

Absolutely excellent video. What a fantastic breakdown from an actual subject matter expert, not dumbed down for a TV audience like mainstream documentaries have to be. This channel is the pinnacle of what KZbin should be. Phenomenal work.

[@kaltkalt2083]

When I was a kid, my dream was to have my own Alvin submersible. Then I learned about money and how much things cost, and I’ve been disappointed ever since.

[@derbybOyzZ]

you should try carbon fibre

[@christopherjones7191]

I hear Ping pong balls survive to depths above calculations.

[@nyssfairchild2244]

That last quote is excellent. "With the appropriate amount of planning, precaution, verification, and ingenuity, it's possible to send a crew almost anywhere. It's never cheap, but that's the cost of exploration. And exploration is what makes us human." We're "only human", but everyone is "only human". On our own, we may not be worth a damn, but that's why it always takes a city to do the greatest things.

[@Alexander-the-ok]

The ridiculous inspiration for that quote is here: what-if.xkcd.com/115/#:~:text=You%20would%20spend%20one%20nanosecond,your%20retinal%20cells%20quieted%20down.

[@ryancraig2795]

And not only that, but do it relatively safely, as the existing world "fleet" of deep sea submersibles has shown.

[@lissettelopez8331]

A positive outcome of the Titans fall is a lot of awareness, and the unexpected interest of submersibles. Watch in 5 years the companies that are being started now that will be established and the availability to venture deep will be much greater.

[@221b-l3t]

I mean.... just build another Aluminaut. Room to stand up for 7 and it even takes like 20 s to walk from one end to the other. Went to 4000 m, at one point holding the record. It's even a cylinder with two half spherical endcaps. But all one material and that material is beautiful shiny luminum... Did like 300 dives and it's still around.

[@Croz89]

It'll be interesting to see if submersible tourism picks up again. These vehicles are very expensive and highly specialised, hence they're only generally used for research, but I don't think there's anything inherently wrong with using them for tourism, especially if the profits go towards funding more expeditions.

[@221b-l3t]

@@Croz89 It's very much alive and well, all over the world. What isn't are DSV's the D being key generally below 500 m, definetly around 1000 m or lower. Neither military nor tourist boats go that deep. They remain comfortably in the above 500 m category, which is deep AF. Plenty pressure to implode in milliseconds. Some of the prettiest (and I guess technically advanced) are built by Triton. They built the currently highest performance, fancy DSV that holds all the records these days and it is fully certified to take paying passengers down. Generally scientists but Hamish Harding took her down to 12 km (DSV Limiting Factor). But you can buy less fancy ones. A million bucks is a good place to start. There are some below but not by a lot haha. And if you want the fancy ones that go extra deep (still not DSV) it's more like 3-4 million. So buying one and then making profit with passengers is something many companies do. It's kinda how Oceangate started, with a 500 m sub. Then they went off and... did their own thing. But there exists a relatively large commercial sub industry. Especially very shallow stuff to maybe 50 m or so there is plenty and it's not crazy expensive. I mean it is but like expensive business class or cheap first type of expensive. Not sell your house expensive. So if you wanna do it and you have a lower middle class job it's very achievable. Some might think you could spend the money more wisely. They are wrong of course.

[@Rhino_Aus]

Your description of the pain of doing real engineering neatly sums up why I get so frustrated as an aerospace engineer talking to drone hobbyist about how easy it is to make something fly... Also; my PhD was on Ti64 ELI and bringing up that stress strain curve triggered an intense PTSD response :P

[@walterbordett2023]

An old saying in aviation applies. "There are old pilots and there are bold pilots. There are no old, bold pilots." That is the difference between Titan and Alvin.

[@briancox2721]

As an engineer with aerospace welding experience, I can say that any weld made by a competent process with a competent operator is capable of being stronger than the parent material around it. The trick with an electron beam (or laser, or any autogenous weld) is that without the addition of filler material, precise fit up and good process are critical. There is no filler material to shove into the puddle to cover your sins, or alter the metallurgy of the weld bead to improve properties. The geometry and fit must be good enough to form the weld puddle and subsequent bead. The parts to be joined must also be properly supported with fixtures and tooling. The atmosphere over the weld must be displaced with the correct shielding gas or removed by a vacuum chamber. Correct pre-heat, post-heat, and subsequent heat treatment, as applicable, must be used to obtain the desired mechanical properties. One part we made at a previous employer was a nickel alloy turbine vane. Sheet metal was formed in a press into a rough airfoil shape, heat treated to remove residual stress from cold work, machined, finish formed in a press, laser welded in a fixture under an argon atmosphere, machined again, and then heat treated for mechanical properties. The welds were both non-destructively tested on every part, and sample pieces were periodically destructively tested. The samples never broke in the weld bead once the process was developed.

[@allangibson8494]

Welds are not stronger than the parent material - because welds are inherently not thermally contiguous. 80% of the parent material strength is a reasonable guess particularly for field welds. Pipeline failures along weld lines are common. A number of catastrophic tank failures confirm this estimate.

[@briancox2721]

@@allangibson8494 your statement is as irrelevant as it is true. Pipeline welds are field welds, not factory welds. Field welds are harder to preheat and control cooling. They are usually impossible to heat treat. Alvin was fabricated in a factory, not the field. Much better process controls. And if you're referring to pipeline weld strength as delivered from the factory, remember pipeline is essentially a fungible commodity. Thousands of feet are made produced. An economic choice is made to forgo certain process controls and steps, accepting lower strength and possible failures. This is also a situation not applicable to the construction of Alvin.

[@allangibson8494]

@@briancox2721 And I have seen plenty of factory welds fail - usually where the weld meets the parent material because any heat treatment is destroyed by the welding process followed by rapid quenching. Pessimism on weld integrity is usually justified. That is why seamless pipe is a thing - avoiding the discontinuity that welds leave in the pipe. 90% of the time the weld will not have the same analysis as the pipe either - because the simple act of heating the material changes the chemical composition of the substrate (and that is without considering the phase changes). Electron beam welding minimises heating.

[@elderbob100]

Well done Sir! Having been involved in video presentations and broadcast video, at the network level, I am impressed with the information presented, and the presentation itself. The information has been presented logically, with proper attention to detail, relevance, and accuracy. The presentation flows; it considers the interests and attention of the viewer. The timing is spot on, the graphics revealing, the voiceover direct and informative. You have a gift for this medium, your outstanding work is appreciated!

[@Alexander-the-ok]

Thanks very much. I’ll be doing similar presentations going forward

[@MatthewAlbert-zoonotique]

Hi Alex, thanks for the great video. Two quick stories: My uncle is a marine biologist who studied "abiotic carbon cycling in undersea vents " --whatever that is. His team frequently utilized manned submersibles, Alvin included. I'm fairly certain he told me the following story was from aboard the Alvin. While ascending one day, the crew heard a loud thump from the side of the submarine. The pilot and crew were unable to determine what caused the thump and eventually decided to continue their ascent. Turns out a large sword fish had rammed the side of the sub and had gotten its nose stuck partway through a very thick gasket(?) that joined parts of the hull. Or that's how I remember it being told anyway. The crew and scientists ate grilled swordfish that night, and somewhere there is a photo of them holding it on deck. ------- I don't think this was aboard the Alvin, but for my birthday one year my uncle sent me an extra large Styrofoam cup that he had drawn on, and tied in a mesh bag to the side of the sub before a dive. The cup was crushed to ~1"x2" but roughly maintained its shape, essentially shrinking the cup. I still have that miniaturized cup 25+ years later.

[@MatthewAlbert-zoonotique]

**The cup was squashed on the Johnson Sea Link**

[@reorseX]

If I had teachers like you back in high school I would be an engineer by now.

[@carlost856]

I had great teachers like him. At my undergraduate and post graduate engineering school. Some really brilliant minds who were experts at communicating their expertise. High School teachers are paid shit and treated like dirt. Places like Switzerland understand this and teachers of all levels are extremely well paid compared to ours, with all the education and expectations that bring on their level of competence. They understand why providing quality education is paramount.

[@ThatSockmonkey]

I certainly would have made different choices if high school maths and physics made this much sense.

[@Alexander-the-ok]

@@carlost856 my wife is a high school teacher. She works so much harder than I do, it’s genuinely embarrassing, yet she makes less than half the salary I do. It’s really quite depressing how little we value teachers as a society.

[@carlost856]

@@Alexander-the-ok yeah even the good ones get burned out from the shit conditions.

[@andydupree9091]

I personally wouldn’t mind more math! You do it elegantly in an easy way to follow.

[@Cologaan]

loved the physical model to visualize what system contributes what

[@Alexander-the-ok]

Thanks. That was a last minute idea tbh

[@a_catfish5180]

Such a good channel and you explained it well breaking down things to where everyone can understand. Showing graphs for those that do and then making an example for those that don’t

[@nikolatasev4948]

I would be curious to see the comparison with the Limiting Factor. That one is new, and is also certified, but cheaper than Alvin's latest update. It can also dive much deeper.

[@Alexander-the-ok]

They are really difficult to compare as they are entirely different classes of vessel. I did some work with mapping data for the limiting factor a few years ago though, it is a fantastic bit of kit.

[@redhelmet8]

37:12 As an aircraft pilot, 100% support and love the decision of the sub's pilot to physically disconnect the wires. Sounds like some of my previous training where we were told to pull all circuit breakers, and then one by one attempt a reconnect to re-establish all but the troubled one.

[@qdusen]

Really a good overview of the level of engineering that went into that vessel. One thing that I would like to understand is how the power gets from the batteries into the pressure chamber. It seems like it would need some serious pressure rated electrical bulkhead connectors of some sort.

[@Alexander-the-ok]

Spot on: there is a ‘penetrator plate’ on the back with bulkhead connectors. I couldnt find a huge amount of info on it so i left it out

[@TheDustyPeaches]

Beautiful, the team that created this vessel made redundancy after redundancy and did not hesitate to add even more.

[@eldrago19]

I know we're not comparing the two but when I saw Alvin was placed together using super high quality welding and Titan was placed together using glue it did shock me. Like that's one step above 'duck tape and prayers'.

[@Alexander-the-ok]

Even the original steel pressure sphere was welded together in temperature controlled conditions. The welders had to keep their torches at a specific distance and only work for so long on each weld so as not to alter the material properties too much. And that was sixty years ago.

[@patnolen8072]

@@Alexander-the-ok Interesting - I hadn't known that Alvin's pressure hull was replaced from a steel hull to a titanium hull. But wikipedia that I'm glancing at just now says this was done after the 1960s sinking and salvage.

[@jthwaits]

Absolutely incredible tribute to the engineers behind Alvin, top job!

[@05Matz]

Great stuff, both engaging and educational. Thank you!

[@whoever6458]

Great video! I learned a lot! I'm still reluctant to even go to sea in a boat seeing as how sometimes ship happens and I don't think anyone would ever catch me dead in a boat designed to sink but I am a nerd and enjoy learning about how people braver than I get in a sub and dive and I appreciate seeing the things they film down there.

[@AllanFolm]

One thing Titan used which was quite smart, was water-degradable links for drop-weights, ensuring a return to surface even if the crew was incapacitated and without any power whatsoever.

[@wshyangify]

Actually I thought the ballast used on the Titan is quite smart too. It's basically some construction grade steel bars. No need to leave your very expensive air tank behind.

[@modernsolutions6631]

Where would you even look up how much concentration of certain minerals/chemicals can differ thousands of meters under the sea to get even a decent estimate over what range of chemical water composition×pressure to test those water degradedable links under. Where would you even start with that?

[@AllanFolm]

@@modernsolutions6631 With SCIENCE.

[@AllanFolm]

@@modernsolutions6631 The concentration of those soluble compounds in seawater at any depth will not influence the time it takes to dissolve the links. Temperature is uniform enough to be a known factor.

[@AllanFolm]

@@modernsolutions6631 The difference between 0 and 0,0001 is not relevant in this situation.

[@skoovee]

i rewatch your videos alot because they are all so good, this is one of my favorites

[@journeymanic9605]

25:15 So you what you're saying is the Alvin knows where it is because it knows where it was, and by measuring where it was from where it is.... I'm sorry but the missile meme lives rent free in my head.

[@Alexander-the-ok]

Me too. That part was kind of an unintentional easter egg: I tried to make it not sound like the meme but it was literally impossible.

[@jozsefizsak]

Fantastic! I remember the loss of Thresher and the creation of the astonishing Alvin but never found much information about it, beyond hearing of it eventually being renamed Alvin II and then once again just Alvin. It's wonderful to learn so much about it after all the years that have passed. 😊

[@youkofoxy]

I had comment on your previous video That wanted to heard you talk about Alvin. And I am happy I got this. Is so satisfying seeing something properly engineered, and some many redundancies against to most diverse failure modes.

[@phartferd5738]

Boy, sure am glad to find put the people who developed Alvin were so heckin’ smart! I hate math and learning so I’m super happy you skimmed over anything of note to talk about how smart and handsome and really good kissers the people who worked on this boat is!

[@TheClumsyFairy]

I learned something new today. I always thought that 'ping pong' balls, or 'table tennis' balls (the same thing) were made from nitrocellulose. After doing some 'research' I found that they were indeed made from Cellulose up until 2014, after which time they changed to being made from ABS. Oh all the stuff about some sort of submarine? nah, boring.. Ping pong balls not being made of Nitrocellulose any more.. PROFOUND!!!

[@Alexander-the-ok]

This is hilarious because I had EXACTLY the same 'table tennis learning journey' as you! I'd seen the videos of people setting buckets of them on fire and creating an inferno because of the flammability of nitrocellulose. But yep, when I looked it up - ABS now.

[@lowcostfish]

When they made the shift there was a big thing about how the new plastic balls didn't spin as well and bounced a little differently. I think the quality of the balls has improved a lot since though.

[@patnolen8072]

I didn't know nitrocellulose had been replaced with ABS. In mid-2000s, I watched someone light a ping pong ball, and it disappeared in a flash of orange flame, leaving no ash.

[@deanchur]

@@patnolen8072 We used to make smoke bombs with them wrapped in aluminium foil when I was a kid. No idea how it actually worked but I saw it being done.

[@adamcollentrials]

I'm studying mechanical engineering, 1st year, this is one of the best most interesting videos I've ever seen, thanks for taking the time to make this :-)

[@Alexander-the-ok]

That’s such a compliment. Thanks.

[@PetesGuide]

What are your feelings about not being able to detach the pressure vessel? That emergency rescue mode was my favorite feature of Alvin as a kid.

[@Alexander-the-ok]

Reading historical accounts of pilots' thoughts about that, the release mechanism and protocols seemed janky as hell! Pilots used to carry a hacksaw to cut through the release bolt in case it jammed, and the functionality was never field tested (for obvious reasons). I suspect the more refined individual component detach procedures may be safer overall.

[@PetesGuide]

@@Alexander-the-ok Interesting! One quibble: I have seen video of it being tested in the field. A Periscope Films KZbin upload. It was clearly the 1964 version based on your wonderful envelope, and may have not been that deep. But it always seemed to me like it should have been the most reliable way back, though I also wondered if it might surface so fast that the crew would be injured after it breached and then fell back down and started bobbling.

[@keith6706]

@@PetesGuide Just looking at the design, it appears very unstable and I can it imagine it rolling badly on the surface.

[@allangibson8494]

The Russian Alpha class submarines had the same system - the submarines sail included a rescue capsule with enough room for the entire crew.

[@PetesGuide]

@@Alexander-the-ok tried to link to the KZbin video showing the detachment, but it got deleted. Check your spam comments folder and release it if you think others would enjoy it. 😊

[@measlyfurball37]

I want to show every silicon valley startup CEO the section of this video starring the ping pong ball estimates to really show them how much WORK engineers have to put into the production of experimental technology. Excellent video.

[@eleanor5675]

Yeah but did they prepare for the scenario that one of the crew members is secretly a vampire that kills everyone?

[@GodofWeird]

Each crew member gets a clove of garlic in their pocket before the dive and during construction they apply a special coating of garlic oil on the interior. And they add mirrors to check each other’s reflections. Sources: trust me bro

[@jemez_mtn]

Wow. This was absolutely fascinating. Great graphics and presentation. Thank you.

[@JeffS96]

I was going to bed! Really cool stuff and I'm only 15 minutes in

[@awg9dog]

I got to jump inside Alvin around 95' when its NOAA surface ship NOAAS Chapman , was in ballest point , San Diego for preparation to the S. Pacific. It had the original oblong conning tower on it at the time. It also had several burn marks along its rear outer structure from exploring a little too close to hyper thermal vents ,heated fissors in the deep canyons around Galapagos island. It was tight for just me inside the sphere. Very honored to be allowed in.

[@Graphene_314]

Wouldnt the strength of the plastic ball be highly dependent on temperature?

[@Alexander-the-ok]

Good point. The material properties given are at 25 degrees C. Obviously my 'test' and calculations were extremely crude though.

[@sharxbyte]

As a fellow Alex who is also fascinated by engineering, design, and tech, thanks for this!

[@witchofengineering]

"The Alvin knows its position at all time..."

[@Alexander-the-ok]

It's almost impossible to talk about Inertial guidance now without accidentally saying 'it knows where it is because it knows where it isn't...'

[@allangibson8494]

INS tells you your position in space. It needs to be corrected for the movement of the planet and solar system around it (it is that precise). It will directly give you longitude based on reading the rotation of the earth around its parked reference plane.

[@tullochgorum6323]

What an informative video! Evan as a non-engineer, I could see that the design of Titan was inexcusably naive. But now I understand what a yawning gulf there is between grown-up engineering and entrepreneurial corner-cutting to save costs. How any sane customer was ever sweet-talked into trusting their lives to that death-trap is beyond understanding.

[@BillionairesArentYourFriends]

It's because no one thinks they're going to be the guy that dies. It's called survivers' bias I believe. Minus the kid, all of them have been on extreme expeditions from deep sea to space and never died doing it those times.

[@tullochgorum6323]

@@BillionairesArentYourFriends There's an element of truth there, but they all had the resources to pay a proper engineer for a second opinion and none of them did. This is rash to the point of insanity. Baffling...

[@PsRohrbaugh]

It is worth noting that a ballast tank doesn't have to exceed sea pressure if a pump is used to help evacuate water. For example, if the absolute pressure of sea water is 6000 psi, and your air is 3000 psi, a pump like what's used in a commercial pressure washer can pump water out of the ballast tank by adding 3000 psi to it. The concern is that now your ballast tank is a pressure vessel, and has to resist implosion. But this is how it's done on submarines.

[@Sbiper]

Not exactly - submarine (main) ballast tanks are not pressure rated. Variable ballast tanks, or trim tanks are however pressure rated and use pumps to transfer water or I gest/expel water.

[@crusinscamp]

Thanks for the video. As a child in the 1960s, I read about the Trieste, Aluminaut, and of course the Alvin, in Popular Science Magazine. There were many good lessons in those articles. I remember the Trieste used gasoline for positive buoyancy, sort of like a deep sea dirigible. It's good to see the Alvin has evolved over the years and is still in service. I'm still a bit curious how they manage hull penetrations for electrical cables, and are there any penetrations for physical controls?

[@Alexander-the-ok]

Trieste fascinated me as a kid. Yep Alvin has a ‘penetrator plate’ behind the crew. It contains pressure tight penetrators for cables to pass through.

[@dvhtosomja1548]

You are overcomplicating things. You could just use carbon fiber tube with two titanium caps on both ends. I bet it would be significantly cheaper, simpler and safer.

[@josephhatfield6237]

Lmao

[@FlourescentPotato]

make sure to glue it in a warehouse with a dirty rag for cleaning

[@Jath2112]

I agree. Skip any and all guidelines and test it live. Fire anyone who tries to tell you otherwise. .... mumble shit about Boeing and NASA and The University of Washington if the public gets nosy.

[@daviddipasquale5479]

I enjoyed this fascinating dive into the engineering a vessel safely navigating in super high pressure sea environments.

[@Perktube1]

Could you please do a story on the submersibles of Jacques Cousteau? I think that would be fascinating.😊

[@Hamdad]

His diving saucer is still one of the only pumpjet propelled submersibles to my knowledge. I wonder why that's not more common. Many SSGNs use pumpjets.

[@selenuntius]

Thanks for the video. I didn't expect to absorb as much information as I did, but I think it was all presented as clearly as possible for the complicated subject matter. I was curious when you mentioned wanting to talk about Alvin instead in the previous video, and I'm really glad you did!

[@PetesGuide]

1) Please don’t apologize for using metric! I was born in California and am gradually switching my life to metric. 2) The U.S. has never used the Imperial system, so please don’t give us those units, because they have the same names but different values than our U.S. Customary System. 3) The one exception to us not using the Imperial system is when us Yanks order a pint in a British pub, because your pints are bigger than ours!

[@allangibson8494]

US gallons are bigger than UK gallons and the US inch was fractionally bigger than the UK inch (but mostly by a rounding error unless you are a surveyor).

[@FergalByrne]

Outstanding. Thanks for this level of depth (pardon me), and for avoiding sensationalism.

[@Thesnakerox]

I just love how this highly engineered vehicle, designed to handle some of the most extreme conditions on earth, is named *A L V I N*

[@alunchisholm481]

"They started using the name Alvin for the sub to honor the prime mover and creative inspiration for the vehicle, Allyn Vine. The name also benefited from belonging to a popular cartoon chipmunk, but Dr. Vine was the true namesake."

[@cameronfielder4955]

And the pos that Stockton cobbled together was called Titan. The nerve of that man rofl

[@GenlackGenlack]

What would you call it, the MOIST PENETRATOR? The SEA BREACHER? The DEPTH TREADER?

[@GenlackGenlack]

"Oh no! The device is sunk and lost forever. Nothing goes that deep." "Wrong! Release the DEPTH TREADER!"

[@vylbird8014]

@@GenlackGenlack Bobby. Bobby the Ball. It's a ball. And it bobs.

[@DerkleineTrojaner]

excellent explanation of the buoyancy systems. nothing better than neat little models to understand basic ideas and principles ^^

[@brianjones3191]

Great name “Alexander the ok.” 😂

[@a-fletcher]

I mean, other than being human and not a submarine I loved this video about Alvin. Super cool to hear all the work that went into designing a safe submersible. Thabks for the amazing video 😁

[@redwolf92]

for me personally, I'd just stick with ROVs. they're safer, cheaper, and ain't having the risk of turning people into spam like a trash compactor. going that deep with personnel with little to no visibility and forcing the occupant to refer at the camera monitor for views just screams "why, though?" to me in capital letters. why risk yourself when you can achieve the same result with less blood on your hand?

[@Alexander-the-ok]

We all have different risk tolerances and appetites and that's a good thing - the world would suck if we were all the same. Personally I'd jump at the chance for a dive in Alvin (well I would have when I worked at a science organisation - not sure I'd want to larp as an explorer with no purpose).

[@redwolf92]

@@Alexander-the-ok well they do call it 'bleeding edge' technology - you can't make an omelet without breaking some eggs I guess. for me, the risks hugely outweigh the gains of doing such trips. if I am a researcher, I don't want to get recognition on my works posthumously lol.

[@CATASTEROID934]

I'd imagine remotely operated vehicles have their own unique engineering challenges but have likely matured a great deal even in the last few decades, let alone since Alvin's original hull was laid down over half a century ago. Crewed submersibles were the convention at the time and I imagine the benefits in the form of situational awareness, adaptability, rapid response time and other such factors of a hosting a human crew member are weighed carefully against the challenges of providing life support and carrying that mass versus eliminating it entirely- it's a similar situation to carrying human crews on space vehicles. Today's hardware is sufficiently powerful, robust and reliable enough that eliminating the crew capsule and support systems from the vehicle entirely and transmitting sensor data through an umbilical from unmanned parasite vessel to a remote operation suite on the mothership is quite economical.

[@allangibson8494]

ROV’s have the ability to kill people working around them - just not generally when in use. The manipulators and pressure tanks are quite capable of pureeing anyone who gets in their way (like all industrial robots). Has power - has hazard.

[@Sashazur]

Deep sea ROVs need a tether; radio doesn’t do well underwater. And tethers can tangle on debris etc. So there’s always going to be a need for a crewed vehicle - though probably not a very big need; it’s likely that a lot of stuff that Alvin does could be done by a ROV. And in a few years we can probably make a tetherless AI ROV that would totally do everything else. Let’s put it this way; if we didn’t have anything like Alvin now would we build it? Maybe not, or maybe it would only be billionaires using them to do record breaking dives.

[@stevengill1736]

"...and exploration is what makes us human"....cheers!

[@beefgoat80]

At first, I hated radians. After I understood them, I began to like them more than the comfortable old degrees I grew up with. Funny how that works.

[@stuartgraca]

Excellent video and encouraging , it is important to value life because it means we value nature, respecting others concerns is also a respect for the environment.

[@ptonpc]

Very nicely explained. Thanks. When building and operating DSV's there is the difference between doing it cheap and doing it well.

[@captainyossarian388]

Your videos are awesome. I loved the Alvin, I recall being mesmerized as a child by the videos of Alvin's expeditions to the depths. I almost pursued being an oceanographer/marine biologist because of Alvin.

[@squ1dd13]

fwiw i think your voice/accent is great. granted im from the uk so i can understand it naturally, but it’s nice to hear people who speak “normally” (i.e. the way i/people i know talk) on youtube once in a while

[@wschuster55]

Your table tennis ball calculations differ from the experimental reality because the pressure inside it is up to 3 atmospheres depending on the production process. Awesome video, thoroughly enjoyed it!

[@pumatato2005]

Awesome to see a video about this! I know a few folks who have studied on Alvin and even some who helped to design/make modifications to Alvin, so it’s great to learn more about it!

[@travhammer]

Mr. Rush may certainly have benefited from these formulations. Informatively great vid

[@r_____________________]

Superb content, I daresay as a biologist it's reignited my passion for engineering! Keep up the great work!

[@Etropalker]

Its just great to see a lot of redundancy here. I love the display of redundancy. The amount of redundancy is beautiful.

[@morefurless]

Found your channel today, very very interesting content!!! I’ve found myself binge watching a lot of your videos!! I can see myself rewatching these videos in the future which you can only really do to very well made videos!!

[@Alexander-the-ok]

Thanks! There should be plenty more of the same over the next few months.

[@morefurless]

@@Alexander-the-ok looking forwards to it!

[@aerox4979]

This video was a pleasure to watch! Can't wait for the next one