Tourist submarine goes missing on dive to wreck of Titanic | Hacker News Reader

Tourist submarine goes missing on dive to wreck of Titanic

theguardian.com

96 pointsKingOfCoders43 comments

Maybe the article just excluded this detail, but is there any reason for a submersible to not have a black box and transponder similar to an aircraft? Do they not work under water after a certain depth?

I feel like the company in charge of all this should at least know where the submersible is, if not what happened to it.

Black boxes don't give real time updates above or below water

There are technical limitations there, the only really viable way to signal from great depths would be sonar. A radio beacon would be useless under 4000m+ of water, and there's no realistic way to ensure that a small bit of wreckage ever surfaces to make a radio beacon work. There's also no legal requirement, there is no FAA for submersibles. Now something like an airplane's black box has an underwater locator that works for a while, but there's no particular reason to expect that a meaningful and timely search can be made at the sort of depths a submarine like the one in the article works at.

tl;dr Rescue and recovery at 4000m+ is pretty much never going to happen, although it is technically possible, and there's no reason to worry about safety standards for something this niche, or limited to militaries.

Radio waves don't work well through salt water. Even VLF signals have trouble going past like 30 meters. There's some super duper low frequency radios but it's still a one-way proposition - build a huge facility on land to communicate with subs, and if the sub needs to reply it has to surface. And even that limited setup is only doable by the military industrial complex of a small handful of nations.

Bit of an understatement.

ELF (Extremely low frequency) requires finding a section of earth's crust with very low conductivity that can be repurposed as an antenna. These antennas are very large, the US had one that was 45km long, the Soviet antenna is 60km long.

The resulting signal has a wavelength of 3500-4500 KM, about a quarter of the earth's diameter.

Because of this huge wavelength, the bandwidth is extremely low. The US system took 15 minutes to transmit a single 3 letter message. The system was only really useful for transmitting pre-agreed signals (which were usually along the lines of "surface and contact us for the actual orders").

But they also acted as a dead-mans switch, they continually transmitted an idle signal. If they stopped transmitting (which would still take several minutes to notice) subs would establish communication to check if a nuclear war had started.

That's fascinating. I'm pretty sure you could post that as its own submission (if you find a suitable link) and it might do quite well.

I'd love to hear if the length requirement can be removed with advancements like phased-array systems or plasma antennas.

Would be cool to be able to text across the world.

They could communicate out via a buoy and really long cable, and in fact that is how a lot of scientific expeditions work. They communicate with a support vessel via cable. However, once the "wreck factor" is introduced all bets are off. Underwater objects being extremely difficult to locate is kind of why they are popular with militaries.

"It was near the titanic at X time and date" is probably the best data you can ever hope for, and that's covered by the dive plan, no tech needed.

How would you implement such a black box? Think it through and think about what useful information could you get from it.

Have a bunch of them that release at regular intervals and float up to the surface.

Where it is and what is wrong would be a good start.

Where it is sort of stops mattering when "what is wrong" is inevitably "It was either forced to surface" or "It's microscopic wreckage."

What is your plan for retrieving the 99.999% of them that indicate nothing is wrong?

Due to an indeterminate crush depth of various electronic media, I would implement it as stone cylinders with chiseled data. The chisel would also act as a sonar signature.

Well, my main question was mostly _why_ it doesn't work (I may not have worded that very well). That said, presuming there was a way to make it work, I'd have it transmit all the available information about what's happening on the sub (respecting any technical limits).

Then if the transponder stops sending data, you know something is wrong. Even if you don't know the exact location, knowing the last depth/speed the sub was at before losing comms, for example, is valuable.

The caveat to all this is, like other comments said, radio doesn't work so well in salt water (which I didn't know).

My understanding is that there are very few options for getting radio signals through the water, especially that deep.

Acoustic beacons exist for underwater position [0]. They usually connect to a transponder on the surface. Not sure this thing had one. Reading this: "This experimental vessel has not been approved or certified by any regulatory body, and could result in physical injury, emotional trauma, or death."[1] makes me think it was a disaster waiting to happen.

[0] https://iopscience.iop.org/article/10.1088/1757-899X/612/4/0... [1] https://www.cbsnews.com/news/titanic-visiting-the-most-famou...

Lowest frequency ones are most effective for deep water and seems lowest operating depth is 6000m which is much deeper than the titanic at ~3500m. see: https://www.skybrary.aero/articles/underwater-locator-beacon....

More discussion: https://news.ycombinator.com/item?id=36391053

They had a journalist visiting before: "A visit to RMS Titanic" - https://youtu.be/29co_Hksk6o

"Experimental vessel..." - https://youtu.be/29co_Hksk6o?t=159

"UK billionaire Hamish Harding on board missing Titanic submersible, family confirms" - https://news.sky.com/story/uk-billionaire-hamish-harding-on-...

Although I feel bad for everybody involved, making billions selling the most polluting transport system on the planet (private jets) and then getting crushed by the ocean certainly feels like karma.

Service Unavailable is what I get when I visit their website. [1] Probably true.

[1] https://oceangateexpeditions.com/titanic

It's weird that I'm just finding out that there's a company that does this when their business goes sideways.

Kinda also wondering if I can scrape 250,000$ together...

There's at least one company that does rides in fighters. Seems a little safer.

https://www.flyfighterjet.com/

Well that's awesome.

"You’ll get a thrilling approx. 45-50 minutes jet ride including:

- A walk around the MiG-29 jet including detailed explanations

- Cruising at double Supersonic Speed (Mach 2)

- Manoeuvres such as rolls, steep diving and climbing and more, depending on what your worked out plan together with the pilot

- A fantastic view onto the earth from above

- You will see the curvature of the earth

- Possibility to control the jet"

"45-50 minutes MiG-29 flight costs EUR 17,500"

That's almost affordable. If my wife ever leaves me, I'm doing this.

Since you can see the curvature of the earth you can also prove it’s round. Big bonus.

Well, you only see that it's bent - you don't go all the way around. Might as well be an upside down wok pan.

Would that be the half-flat theory? ;)

https://www.smbc-comics.com/comic/flat

Nope. It's the shell of the turtle.

It's 4 elephants on a turtle swimming through space.

Everyone knows they have specially shaped cockpit glass that warps your FOV to give the appearance of a round earth.

Well it's a bargain, I guess, compared to the current ticket prices for space tourism-- which is still in the 7-figures range.

It's got to be an extreme rarified market where normal rules just don't apply.

How many potential customers are there that have the kind of disposable income to pay for a one-time "experience" and ALSO a tolerance for risk that is somewhere between race-car driver and wingsuit-enthusiast.

I think this bit of marketing helps too.. “95% of the Earth’s ocean is unexplored. You can change that.”

Their money is going to philanthropic activity exploring the oceans.

What is philanthropic about spending "a million dollars on gas" per trip to send some billionaires on a glorified elevator ride?

I suppose very little in some people's eyes maybe more in others. I think it depends on how much unexplored ocean this team dedicates their budget towards exploring.

You are probably not their target demographic. People who spend $250,000 on vacations probably hear about it regularly.

https://incredible-adventures.com/ has been offering wild adventures similar to this for a long time.

Looks like the company’s website is down (https://oceangateexpeditions.com/).

It's working for me. Maybe a bit of a hug of death

Ironic.

They are likely lost forever. Even a pinhole at depth puts enough pressure into the cabin to liquify everyone inside moments before the external pressure crushes the vessel like an empty can of soda. Assuming it was not a loss of pressurization or hull related failure - say it was electrical or mechanical, it is very cold i̶n̶ s̶p̶a̶c̶e̶ on the ocean floor.

https://twitter.com/OceanGateExped/status/166937494022143590...

Maybe Elon Musk can help out and make it about himself by calling the people working on the rescue team pedophiles.

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