Stupid question, perhaps: was/it possible for this sub to have any kind of beaconing or communication system that works at depth? It seems like one of this first things I'd investigate before deciding to build a sub.
I was wondering how naval submarines work when they get in trouble.
I would expect to see some sort of emergency button (internally) that you could press, that would release some sort of buoy, that would float to the surface and start transmitting with gps etc. I think that would help narrow down the search.
The buoy would be in an external container (to prevent pressure problems), with explosive bolts or something to release.
From what I understand, naval submarines typically have a signaling device called an EPIRB mounted in such a way that it's released automatically if the sub dives significantly below crush depth and/or if a switch isn't activated on some set interval. Then it pops up on the surface and says "Hi, wreck here."
I don't think the former system would have worked here anyway, since the sub is supposed to get very close to the bottom.
They had this but there were problems with it, if I recall correctly. So it would be disabled in "times of war" or whatever because if it accidentally popped off it was not a good time for you.
”The submarine's emergency rescue buoy had been intentionally disabled during an earlier mission and it took more than 16 hours to locate the sunken boat, which rested on the ocean floor at a depth of 108 m (354 ft).”
> I was wondering how naval submarines work when they get in trouble.
Naval subs in trouble?
They go "forever on patrol." A naval sub is an espionage watercraft; signaling an emergency isn't exactly in the playbook for most of their mission cycle. ;)
Spanish/Egyptian. Where the person who was supposed to be a Scot had a Belgian accent.
I'm quite fond of the Bond film where he was disguised as a Japanese man, and all the actors pretended to be fooled. 6'2", with chest hair poking out of his kimono, an obvious wig, and speaking broken Japanese with his typical Scottish brogue. "Arigatoo gozzzimash"
Its practically impossible to do satellite to undersea communications. Being underwater does all kinds of hell to RF signals. Even just reliably doing undersea to surface communications is pretty tricky.
Is your phone waterproof? Stick it a sink full of water. Watch it lose all network connectivity.
I wonder what the drift would be like if you released a buoy 2 miles below the surface. You could theoretically have the last estimated location of the sub, but even then that's largely an estimate as its not like the sub actually has a GPS fix its all dead reckoning.
They already know about where the sub should be, somewhere around the Titanic wreck. If an untethered buoy pops up a few miles away, does it really do much to help clue you into where they are? And if its not much to put a tether on the buoy, why not just have the craft be tethered from the start?
I tried to research, but it's not clear. It says the gulf stream can reach 5mph, but also that that is near the surface, and it's slower the deeper you go.
A buoy ascends at 2.8 m/s. 3000m would yield, meaning about 18 minutes of rise time.
If we assume that water is at max speed the whole way through, we'd be talking about 1-2 miles.
Realistically, because most of its rise is in deep sea conditions, I imagine it'd be less than 1 mile.
But, if it made contact as soon as it reached surface with a GPS location, I'm sure some scientist could calculate about how far it drifted from the water conditions. I'd imagine they could get it down to a few hundred foot radius?
The sub had a limited acoustic telemetry system for transmitting to the host ship. That signal was lost, so presumably the sub has suffered some type of serious failure.
So perhaps the best you could do here are something like emergency buoys that either one can record data on or perhaps automated recording some stats/location/whatever that can be released in an emergency and send a broadcast once topside?
what about fiber ? <4kg per km. throw at end powered buoy. maybe inflatable to hold more of it. currents still will be mess, but with lower than copper weight you could have a few km slack
I think your assumptions are unrealistic. A fiber optic cable weighing 4kg per km with no other reinforcement or protection would be extremely fragile.
According to my back-of-the-envelope math, using the density and tensile strength of typical glass, it would have a breaking load capacity of around 10 newtons (roughly 2 pounds of force). Even a steel cable with the same weight would only be about 20 times stronger.
4kg/km it's not for clean glass fiber. it's fiber drop cable, in whatever plastic sleeving + a couple of steel strands for some added rigidity/structure.
there are also versions with kevlar braiding to protect core and improve resilience.
Yes, you'd think emergency procedures would be at the top of the list right after you made a viable pressure vessel.
They obviously didn't do this. They previously lost the sub for five hours. Why this doesn't have an emergency buoy, or an locator beacon that works when the ship surfaces, I don't know.
