Can you expand? To a layman like myself, tracking is part of communications and it seemed clear there was no tracking because they didn't know where the sub was.
What is the specific type of tracking device you're referring to? What signals does it emit? And if overall power was lost, for example, why wouldn't the tracking stop just like communications stopped?
To clarify EM waves which are used for most(all?) tracking in the atmosphere, are attenuated very quickly in water. Underwater sound waves work better. I don't know what this submarine used but I would expect at minimum an acoustic transponder to aid in underwater tracking. with a acoustic telephone as a comm channel. However reading about some of their other engineering decisions this is probably too optimistic of me.
Data recorders(airplane black boxes) have a sound pinging unit for this exact case. being lost under water.
> Submarines cannot communicate more hundred meters in the bottom of sea.
Sorry if I am misunderstanding you. It sounds like you are saying that it is impossible to design a system which would be able to keep in contact with the submarine/submersible all the way down to the bottom?
Because if that is what you are saying that is simply false. We have the technology to keep in contact with a submarine all the way to the bottom of even the deepest oceans.
This is not even speculative. We know it is possible because James Cameron had full communication during his dive all the way to the deepest point on earth. Here is a really cool article about the technical challenges with that system: https://www.hydro-international.com/content/article/communic...
If you read the article, you know that the context was extremely specific and not suitable for general use.
The noise is too big problem.
In ”normal” context such signal is not currently known to be really possible.
You know that submarines are not equipped with these.
The ship on the surface had to drop cable 100 meters below the ship to combat noise.
Which means that for communication to be possible, ship cannot really move.
And the ship is supposed to be almost directly above the submarine, to reduce the noise again.
For signal to be practical, it should go either over the surface or go long distances horizontally and be usable even with some noise.
Rest assure that I have read the article i have linked.
> the context was extremely specific and not suitable for general use
What does general use mean? The context is the same. We are talking about an expeditionary submersible having constant and reliable communication with its support ship all the way to the bottom. This was the setup of Cameron’s dive and this was the setup of the ill-faited Titan mission.
The people lost lived on the support ship, and only boarded the submersible when they arrived right above the Titanic. There the crew from the support ship bolted the crew of the submersible in, and the support ship remained in position and in communication with them until they lost that link. Then they waited for a long time, and only when the submersible was overdue that is when they raised the alarm. The only reason why we did know that the submersible went missing is because those on the support ship raised the alarm.
> And for that there is no reliable technology yet.
You can say that, but you are wrong. Sound waves propagate very well. I think what you might be confused about is that military submarines do not communicate with the shore during operations. They remain silent because if they start to transmit everyone will know where they are. But that is not because there is no reliable technology for it. In fact they can just blast a loud sound wave out with their active sonar and everyone all around the ocean will hear them who cares to listen.
I'm not saying that it is easy. All I'm saying that it is perfectly within our capabilities if we want to.
I think for 3-4km it’s practical to run a wire from the surface all the way to the submersible - that’s what they do for torpedos and anti-tank TOW missiles.
> Sorry if I am misunderstanding you. It sounds like you are saying that it is impossible to design a system which would be able to keep in contact with the submarine/submersible all the way down to the bottom?
You can always throw a cable down, if you have a handy 2kM long one.
Personally I'm not sure most people can actually grasp the scale of the ocean on it's own. We have the best we have already - transponders.
Assumptions are very dangerous, you've made a few here and that's unfortunately the mentality that can result in disaster.
The assumption being that its easy and should just be a 'given'. The problem is with that and not proper testing/validation you can have false confidence in the systems.
The article is actually really interesting, but it's exception, it's certainly not impossible.
I have made no such assumption. The person who I was responding to said it is not possible. I said it is possible to do. That is all the claim I'm making.
Of course it is very hard. It is kinda implied by the fact that I linked an article about the technical challenges! If you order some custom built equipment and the company then later writes an article about all the challenges with it, you can bet that it was a super expensive and specialist device.
> When the signal is lost, the expectation is that the submarine is under the water.
Yes! This is true, I would just like to clarify that there is a difference between 'coms' and 'transponder' here. Some friends of mine conflate the two and think they are almost on the same 'circuit'.
In most cases of the Sub (specifically military because there are not many tourist subs), you don't WANT to be located unless in an emergency, whereas here in this situation you most certainly do and in that case you can be located by way of the transponder.
So we're actually really good at enforcing circuits and components against atmospheric pressures. Also they run relatively low voltage.
As an example I can immediately think of the Compatt devices, they're tested and proven far beyond 4Km depth, and they come with a few options of power supply.
They have their own independent power source as you would expect, but depending on the configuration can pull from the device / vehicle.
The v4 of the Compatt also comes with extensive warnings around the power draw in relation to reserve so if for example they left and it was only on battery-power for some reason, it will start screaming.
The fact that from reports (obviously we don't know for sure) they went at the same time, sadly Occam's razor.
Edit : Disclosure : Worked on firmware for off-shore drilling rigs with devices measuring the vibrations and resistance of material being probed for viability.
What is the specific type of tracking device you're referring to? What signals does it emit? And if overall power was lost, for example, why wouldn't the tracking stop just like communications stopped?