Learn to speak "Submariner" - your handy guide to submarine terms

[Transhumanist]

EM emission can't be detected outside any metal shell. so a personal computer on wifi will never be noticed outside.

Talk to @SvenSvensonov about that, I'm sure he wont agree. Impurities in a submarine's hull, such as welds, the individual properties of each metal type (its resistance to RFs) there are more factors that go into blocking RF or EM signal beyond something just being metal. Not every metal stops RF or EM signals anyways, magnetic permeable metals actually increase the propagation and occurrence of RF and EM signals - they don't block, they draw EM and RF to them, thus concentrating those signals in large "pockets," but that would prevent said signals from escaping the sub and thus would severely limit wifi communications.

 

[AugenBlick]

Talk to @SvenSvensonov about that, I'm sure he wont agree.

but its basic electrophysics (not my strength , i'm a mechanical engineer)... EM radition can not penetrate a metal shell....unless its a composite / designed for EM transparency.....
That is why mac books , even though aluminum have plastic hinges below their screens.

 

[Transhumanist]

but its basic electrophysics (not my strength , i'm a mechanical engineer)... EM radition can not penetrate a metal shell....unless its a composite / designed for EM transparency.....
That is why mac books , even though aluminum have plastic hinges below their screens.

Nope, there will be leakage:

EM waves can penetrate metal shells to a certain distance, but are attenuated (weakened, but not suppressed or destroyed) as they travel through. The wave will be mostly reflected, but the remainder will travel through being exponentially attenuated.

So a thin film of metal will have some small amount of EM radiation leak through. Make the metal thicker and less will leak through.

Materials Research

This leakage is significant enough that it can be detected and pieced back together. Talk to @SvenSvensonov this was his job in the Navy - he had a major focus on submarine communications, he'll be a better source of data than I can be on submarine EM properties. He's done a number of threads on the topic, I've tracked them down:

What is Electronic Warfare? - The Basics

Principles of EMSEC

EMSEC - What is it?

Soft TEMPEST - electronic eavsdropping

EMSEC - Communications Security

 

[MastanKhan]

Not really, when they have downtime, submarine crews are allowed to use the wifi for personal communications, even when at sea. Submarines are specifically designed with all-aspect emissions suppression, this included electronic communications. Not only that, but submarine communications are highly directional, and this means that to eavesdrop on them you need to get between the submarine and its relay. That's not easy.

If said relay is a satellite, you need to first find the sub, then the satellite and get between them and stay between them while you spy on their communications. Aircraft tend to travel too fast; surface-ships are too noticeable.

If the relay is an aircraft, well, an aircraft is going to notice something underneath it and it will stop acting as a relay until the threat is gone.

Submarine communications are secure, and using wifi isn't going to give away their position, using wifi just isn't too common for personal use, not because its dangerous, but because submarines tend not to have too many computers due to space limitations. There's only so much you can put on one.

@SvenSvensonov anything to add or correct?

Hi,

So---how do they do it---send it in a short burst----. But then they have to surface or close to surface---is that right----or pop up the antennae.

VLF ELF, VHF----

If the aircraft notices something---the sub is exposed----

 

[Transhumanist]

Hi,

So---how do they do it---send it in a short burst----. But then they have to surface or close to surface---is that right----or pop up the antennae.

VLF is commonly used, while most radio frequencies are foiled by seawater, VLF are able to penetrate nearly 20 meters of seawater, this still means they need to come relatively near the surface, but they don't need to expose an antenna above water either, they can stay submerged and communicate.

HOWEVER, and this is important, VLF arrays are too big for submarines themselves, typically several square kilometers, thus submarines only have VLF receiver antenna.

Because of their narrow bandwidth, VLF also can't carry audio messages, and they transmit very slowly: VLF data transmission rates are around 300 bit/s - or about 35 8-bit ASCII characters per second (or the equivalent of a sentence every two seconds) - a total of 450 words per minute.

ELF can penetrate hundreds of meters of seawater, but again, their arrays are too large. This is the Clam Lake ELF facility as part of the now-closed Project Sanguine

You're not putting one of those on a submarine.

ELF communication works on the Reed-Solomon Error Correction that relies on transmitted code-words to be received for a coded signal to be decoded. 1/2 of the coded signals must be sent for the message to be valid. Because of their low signal-to-noise ratio, the ELF form of communication is considered very secure, if only because there aren't too many pseudo-random sequences representing actual message characters, and thus there aren't too many ways to spoof an ELF receiver.

So this is how a shore-based communicator would talk to a submarine, but how do submarines communicate with the world outside?

The current standard in the USN is the SSIXS - Submarine Satellite Information Exchange Sub-System... unfortunately details are classified so I can't really go into depth on it.

Perhaps @SvenSvensonov can give us some non-classified details?

 

[Donatello]

VLF is commonly used, while most radio frequencies are foiled by seawater, VLF are able to penetrate nearly 20 meters of seawater, this still means they need to come relatively near the surface, but they don't need to expose an antenna above water either, they can stay submerged and communicate.

HOWEVER, and this is important, VLF arrays are too big for submarines themselves, typically several square kilometers, thus submarines only have VLF receiver antenna.

Because of their narrow bandwidth, VLF also can't carry audio messages, and they transmit very slowly: VLF data transmission rates are around 300 bit/s - or about 35 8-bit ASCII characters per second (or the equivalent of a sentence every two seconds) - a total of 450 words per minute.

ELF can penetrate hundreds of meters of seawater, but again, their arrays are too large. This is the Clam Lake ELF facility as part of the now-closed Project Sanguine

You're not putting one of those on a submarine.

ELF communication works on the Reed-Solomon Error Correction that relies on transmitted code-words to be received for a coded signal to be decoded. 1/2 of the coded signals must be sent for the message to be valid. Because of their low signal-to-noise ratio, the ELF form of communication is considered very secure, if only because there aren't too many pseudo-random sequences representing actual message characters, and thus there aren't too many ways to spoof an ELF receiver.

So this is how a shore-based communicator would talk to a submarine, but how do submarines communicate with the world outside?

The current standard in the USN is the SSIXS - Submarine Satellite Information Exchange Sub-System... unfortunately details are classified so I can't really go into depth on it.

Perhaps @SvenSvensonov can give us some non-classified details?

How long is the ELF/VLF antenna on the shore to transmit to submarines? Must be a full wavelength long,right?

 

[Transhumanist]

How long is the ELF/VLF antenna on the shore to transmit to submarines? Must be a full wavelength long,right?

I don't know the specific wave-lengths (it's reportedly 76 Hz though) - I'm not afforded that info, but this is an individual antenna for Project ELF (shut-down in 2004):

There are dozens of such antenna for a given array.

 

[Moon]

Yeah and the roooskie will slide a torpedoe up the boats arse.

During peacetime?

 

[MastanKhan]

During peacetime?

What peace time----rooskie have never been able to track one sub for a minute. That was just a matter of speech.

The connection is like a micro busrt----not something like---hey bud whats up---you smoking----.

 

[S.U.R.B.]

Rig for silent running is the one I remember hearing the most. It basically means what it says, STFU and keep that way, we're not supported to make noise.

Rig ship for lady visitors I heard this one too. Never for when we had ladies, but always for senior officers. Put your p*rn away and watch your language.

Mushroom Club Submariners refer to themselves with this. It means they feed us, but keep us in the dark. We never truly know what the hell we're doing, most submariners don't even know where they are at any given point.

Reactor scram Another joke we played on people who didn't belong, N.U.Bs mostly. Like fetching a water slug, reactor scrams are BS in really life, but it sounds scary and keeps people away from places they shouldn't be for fear of radiation contamination.

Sherwood Forest We didn't have one on the boats I was on (not with nukes anyways), but this is a SSBN's missile tubes.

“Smile! At least your wife is getting laid” A fun way to piss off a sailor, it works best the longer they've been at sea.

Single digit midget This was me from time to time. Anyone who spends less than 10 days on a sub before returning to port.

“There is tit in the third reel” any movie shown that has bo*bs. We rewind those a lot.

“You have two hand and three holes. Cover the ones you don’t want hit first” The first thing you say to your wife after returning home.

Sweet terms and phrases.
Bookmarked.

 

[Indus Pakistan]

@Transhumanist Reading that had me enthralled. You guy's are the real stuff ......
I could not spend more than ten minutes inside a sub ....