Just had my first ever submarine experience. How did they communicate with the world?

[Dallsim]

After joining the forum, I decided I mind as well learn a thing or two about submarines.

Strangely enough, my first ever experience in a submarine just happened to happen this weekend while I was on holiday in Hamburg, Germany. They had a Russian submarine (U-434 or B-515 in Russian) docked at the port, which was now open and used as a museum (since 2002) for the general public.

My girlfriend is very much into history (pre and post world war) and luckily mentioned the fact that there was a submarine open for visitors in the city. She was surprised to learn that I immediately showed such interest in visiting and I am happy we made the choice to go :)

Unfortunately, they did not seem to have a guided tour in English so I had to rely on my secondary school German skills for most of the tour, which was held in German. My girlfriend speaks the language fluently so I was able to ask a FEW questions after the visit but obviously wonder about a lot more things and hope to get some clarifications from other subsims' forum users if possible.

What I learnt during the tour:

The submarine, or U-Boot as it is called in German, was approx. meters long and 15 meters tall. It could go down to 400 meters maximum and would collapse at 600m. The crew would consist of 84 marine soldiers all together and the submarine would have to come up for air every 3 days. They were mostly at sea for 3-5 months depending on the mission. It was diesel driven mostly around surface but switched to batteries when going deep. Temperatures were 40 degrees Celsius and further 60 degrees in the engine room, which shocked me like crazy! Also, when enemies or perhaps other boats would pass by, they had to switch off the engine and remain completely silent, thus having to turn on the heaters to stay warm. Otherwise they would freeze to death!

Everyone worked 12 hours a day and would sleep or relax for the other 12. There was very little space to move around in, and my recent slight knee and hip injury made it extra difficult to get around. The ideal height for a person would be 160cm, making it quite straining on the back if you were taller. The submarine innards were clearly not made for esthetics but rather function. The rooms were small and the beds were short. The only room with proper space and bed size seemed to be the "panic room", most probably for good reason.

What I definitely took an interest in was with outside communication but do not think too much was explained. How did the submarine communicate with the outside world? On top of the submarine, you could see communication tools in the front section of the sail, like a satellite of some sorts with two periscopes to the back. How was communication between the Russians done securely without it being intercepted or modified? What was the technology like back then compared to now? Are there still any similarities? My girlfriend claimed it was possible to hear speaking "sounds"
coming from a submarine if you were above sea level. Is this actually true?
Man, I have too many questions :)

My girlfriend had not heard of the film "Das Boot" so we will watch this once we're back in the country. Also, "the Hunt for the Red October" should be next on the list. She had at least heard of that one.

http://www.u-434.de/index.php (German only)
https://en.wikipedia.org/wiki/Soviet_submarine_B-515

[Osmium Steele]

Pictures of B-515 show an HF whip antenna precariously mounted on a mast.
HF can be used for voice/morse or teletype but is a very high powered, omni-directional (easily detected) signal.

Soviet submarines used a VLF receiver system similar to NATO boats. Think of it as a news organization's wire broadcasts where anybody tuned into the right frequency, and possessing the appropriate decryption gear, can read the broadcast.

That aft mast looks like a VHF and/or UHF antenna. Standard comms for the period and even today. Everything from satellite to teletype and voice.

Not being an expert on Soviet era communications though, I'm certainly correctable on this.

[Onkel Neal]

Count yourself lucky your gf has an interest in history, that's rare. :Kaleun_Thumbs_Up:

[Dallsim]

Soviet submarines used a VLF receiver system similar to NATO boats. Think of it as a news organization's wire broadcasts where anybody tuned into the right frequency, and possessing the appropriate decryption gear, can read the broadcast.

I had to google VLF receivers and transmitters but interesting to read that VLF waves penetrate down to 40 meters in saltwater and that the submarines had to come up floating some sort of towed antenna just below the water surface. If the submarine were submerged deep in the water while in enemy territory, were they forced to come up in order to receive status updates and new orders? How were they able to remain "in the game" while deep under water?

That aft mast looks like a VHF and/or UHF antenna. Standard comms for the period and even today. Everything from satellite to teletype and voice.

So are you saying that, even with today's technology, a submarine would still need to come up to the surface to receive updates? What about communcating under water? Could they get information under water from a friendly submarine that was in a safe area?

Count yourself lucky your gf has an interest in history, that's rare.

She is only in her late twenties but loves to read world war fiction. Don't know which books exactly but have seen her carry plenty of Ken Follett books around. Cannot judge the quality myself but any book with such themes seem to be on her reading list. Latest TV-series she gave 5 stars on Netflix was a show called The Midwife by the BBC. And no, she's not signalling to me that she wants to get pregnant :)

[CaptBones]

VLF wasn't in use during WWII or for much of the Cold War. VLF messages are very short coded signals; not quite like Fleet Broadcast message traffic and definitely not for 2-way communication.

Getting and sending messages over long distances in WWII and during much of the Cold War was done primarily with HF, using wire or whip antennas....had to be on the surface to send but could receive with wire antennas at shallow submergence. I once established and maintained a two-way "full period termination" teletype link with NAVCOMMSTA Pearl Harbor (Wahiawa) from the North Pacific "Broad Ocean Area", over 2,500nm, with a 55W...55 Watt, not kilowatt...transmitter. Ham radio operators do that, and better, all the time.

Later during the Cold War and today, UHF, VHF and EHF satellite uplink/downlink became the primary methods of two-way communication, which requires putting an antenna on or above the surface. HF Broadcast is still available and can still be received at shallow depths with towed wire antennas. Keep in mind, submarines are the "Silent Service"...they do not transmit unless compelled or required to do so.

[Dallsim]

Getting and sending messages over long distances in WWII and during much of the Cold War was done primarily with HF, using wire or whip antennas....had to be on the surface to send but could receive with wire antennas at shallow submergence.

Perhaps this will be shown in Das Boot, Red October or some of the other films you suggested, but do you have an example of how they tactically rose to the surface without being detected by nearby enemies? Say the submarine needed a status update before committing to strike, how would they go about getting this information? Also, what type of decryption methods were used by the enemies? In the heat of the moment, where it was paramount not to be detected, would submarines have to carry out orders that were already set when departing on the mission? I.e., no turning back once things got heated?

Keep in mind, submarines are the "Silent Service"...they do not transmit unless compelled or required to do so.

Why would a submarine be forced or required to transmit? The U-434 or B-515 could stay submerged up to 3 1/2 days. Would it be to get "sick" crew off the submarine or to report on important findings? How many percent of crew on "injury reserve" could a submarine afford?

[Osmium Steele]

If the submarine were submerged deep in the water while in enemy territory, were they forced to come up in order to receive status updates and new orders? How were they able to remain "in the game" while deep under water?

It is called the "floating wire" for a reason. ;-) The boat can remain submerged at a certain depth and the wire floats to the surface. Boat speed is restricted because the wire will stretch and break at high speed due to surface tension. Oh, and radiomen hate the darn thing because you WILL get wet deploying or retrieving it. (stupidfloatingwireihatethatthingstillhavenightmar es) However, most VLF broadcasts are received at periscope depth utilizing the standard antenna, which doesn't have to break the surface to receive the VLF signal.

So are you saying that, even with today's technology, a submarine would still need to come up to the surface to receive updates? What about communcating under water? Could they get information under water from a friendly submarine that was in a safe area?

The surface, no. Periscope depth, yes. Though I am told that Virginia class boats have a retractable comms buoy so the sail doesn't have to get near the surface. I'm personally skeptical of such newfangled tech.

The sail breaking the surface at PD used to be a problem in high sea states. And if the boat had fairwater planes instead of hull mounted dive planes, the sound of those slapping the water could wake the dead.

And yes, submarines can communicate with each other underwater, via sonar, if close enough.

[speed150mph]

As the others have said, there is no way for a submarine to establish long range communications from deep depths. In the Cold War, and in the russian navy still, a submarine can be called to the surface by an ELF transmission, but the frequency is so low that it can take a minute or more to even send a single letter in a message, but can penetrate the water.

For a submarine to transmit or recieve longer messages like updates or orders, they need to come to periscope depth and raise the mast or stream the floating wire depending on situation. The mast can be picked up on radar, but you can also put up your other masts and periscope and take a peek and listen to other activity around you. The floating wire is less detectable on radar, so would be used in times where possibility of detection was high.


As for why a submarine would transmit, the main reason would be just to check in at home, post a position report and let their bosses know that everything's fine. If a sub is out of contact for too long the are declared missing and a search is conducted...

Other reasons include contact reports, intelligence reports, acknowledgement of orders, damage reports. Pretty much anything that their squadron CO would want to know immediately. Obviously in times of war or during covert ops, these would only be done when able, a submarine attacking a carrier group won't tell the boss he's about to shoot and give himself away.

[CaptBones]

Uhhmmmm…folks…it seems to me that we’re mixing a lot of apples and oranges, adding a few pomegranates and then throwing in an avocado or two for good measure.

First, it would be helpful to remember that there are huge differences in the technologies, strategic employment and tactical operations of WWII submersibles and Cold War submarines. There are also significant differences between today’s submarines and those in service during most of the Cold War.

Second, we should also keep in mind that the WWII German and US submarine forces were very different in many of the ways they operated, but similar too. Not to mention that there are even greater differences between the operational doctrines of today and during the Cold War, and those of any/all WWII submarine services.

So…perhaps we should be clear about the era we’re writing about with each comment we’re writing. Let’s start with this:

Q: “…but do you have an example of how they tactically rose to the surface without being detected by nearby enemies?

A: Which “they” are you referring to? Considering submarines in WWII, “they” didn’t. In general, you wouldn’t surface close to the enemy unless you’re; a) critically damaged and intend to surrender (or fight it out and die valiantly) or; b) “the enemy” is a lone unarmed merchant vessel you’re going to engage with deck gun or; c) it’s the middle of the night and you’re going to engage on the surface.

Q: Say the submarine needed a status update before committing to strike, how would they go about getting this information?

A: That doesn’t really fit in with WWII submarine warfare; what kind of “status update” are you thinking would be needed? To quote Dudley W. Morton; “Find ‘em, chase ‘em, sink ‘em.” Despite the differences in operational methods, the German and American submariners both essentially followed that doctrine. The biggest difference was in the German “Wolfpack” method of operation. There, the gathering and concentration of units to attack a convoy was coordinated and controlled by the HQ Command ashore and that did depend on a steady stream of 2-way communication between the individual U-Boats and BdU. Unless detected by the enemy, the boats would travel to the designated intercept position on the surface and would get updated reports on the convoy and orders from HQ by Enigma-encrypted radio messages (good scenes of that in “Das Boot”). That turned out to be an Achilles heal though; radio direction finding equipment was finally installed aboard ships and aircraft as well as ashore and the ability of the Allies to detect and localize U-Boat transmissions was one of the factors in defeating the wolfpacks.

Q: Also, what type of decryption methods were used by the enemies?

A: That is a story in itself. Google “Enigma” and see what comes up; by all means see the movie “The Imitation Game”. About the only redeeming quality in the movie “U-571” (don’t have a hissy-fit Sailor Steve;>) is the dedication, in the closing credits, concerning the capture of Enigma materials during the war.

Q: In the heat of the moment, where it was paramount not to be detected, would submarines have to carry out orders that were already set when departing on the mission? I.e., no turning back once things got heated?

A: Yes, but with due consideration for the command and control procedures inherent in the “Wolfpack” tactics. Not to put too fine a point on it, but the mission orders were generally very broad…“Proceed to ‘such and such’ a position/area and then “Find ‘em, chase ‘em, sink ‘em.” Of course, there were a lot of special missions as well and those orders would be more detailed.

Q: Why would a submarine be forced or required to transmit?

A: With respect to WWII German U-Boats, that goes back to the “Wolfpack” tactic and the need to communicate between the boats and the HQ ashore. USN subs in the Pacific had much fewer requirements to do so. They did not report their arrival in a patrol area or their positions...unless directed to do so by their Op Orders or by message. But, they were required to report when enroute back to port from patrol and they also needed to copy the “Fox” Broadcast for revisions to orders, contact reports and general information of use to carry out their mission orders.

If you want a lot of accurate and factual information, there are a plenty of good books on these subjects (and a few not-so-good). There are also a couple of threads right here on SubSim that concern the real world of WWII submarine warfare in the Atlantic and the Pacific. Have fun getting “submerged” in all of it.:salute:

[Oberon]

B515 is a Tango diesel electric submarine, so she would be rather quiet, if I recall probably one of the quietest diesel boats the Soviets had until the Kilos.
So...communication. IIRC generally speaking orders would be sent at specific times during the day during which time the submarine would either put up a mast if the coast was clear, or stream a wire if it wasn't. A small line of wire is not that easy to pick up on radar and unless you're pretty much on top of it it's also harder to see than a mast which leaves a trail.
That being said, in certain waters, such as the Pacific, if you're that close to the surface then a passing helicopter might actually be able to see the submarine in the clear water, not exactly ideal, so if a helicopter was detected by the submarine then chances are it would just avoid being near the surface wherever possible or spend as little time up there as possible.

Let's also bear in mind detection, radar is generally done through a series of sweeps and radar returns can be made off all kinds of rubbish in the sea, so if a submarine sticks up a scope and a ship gets no more than two returns off it, the radar operator may classify the returns as ocean clutter, which is when the radar reflects off something random on the sea, like a flock of birds or something. So a quick sub commander can get a mast up, do a sweep and slam it back down again before the surface radar operator gets a solid lock and determines that it's a mast out there. That's one of the reasons that submarines like the Astute and Virginia classes have periscopes that are essentially a load of video cameras around a pole, you can pop it up, grab the footage you need, drop it down again and then analyse the footage you've got without having to leave the mast up or suffering motion blur as you turn the scope around quickly.

There is another method, and that's ELF (Extremely Low Frequency), and this is mainly used for missile submarines in order to tell them to come up to periscope or wire streaming depth in order to receive a more detailed message, since ELF has a very slow transmission time and as such is really only suited for short messages. If you've seen the film 'Crimson Tide', you'll see that they get an ELF message to bring them up to communications depth in order to receive missile targetting instructions.

And, of course, there's the underwater telephone for communication between submarines. IIRC the nickname for it is the Gertrude and it's pretty primative and often a bit like trying to have a conservation on a very bad phone line, but it does work.

In the future, there's a lot of talk about laser based communications, a bit like fiber optics but through the water rather than a fibre tube. The precise physics of it are a bit beyond me, but I do know that laser comms on submarines is something that has been mulled over for a while now and it wouldn't surprise me if it is in actual service but on a classified trial basis.

I hope that makes sense...and that any sub experts can correct me where I've gone wrong, I'm certainly no expert but I have read a bit over the years, especially around Cold War submarines (my favourite era) and so I've picked up the odd thing here and there. There's some articles I'll link as well for some extra reading:

https://en.wikipedia.org/wiki/Communication_with_submarines

https://en.wikipedia.org/wiki/Underwater_telephone

http://www.sea-technology.com/features/2011/0511/laser_communication.php

http://www.naval-technology.com/features/featuredeep-secret-secure-submarine-communication-on-a-quantum-level/

[l02turner]

Ya'll probably know this but the Germans had a weakness when it came to communications - the allies broke the code pretty early and I believe it was Sub overall commander Doneitz who required all subs to report their position on a daily basis, This allowed the allies to direct convoys around the wolfpack positions and avoid them completely. The Germans were convinced we could never break their code but the Poles were hard at work on it early. Before the Germans invaded in 1939 the Poles destroyed all evidence and even though they were tortured none spoke of their work.

[Osmium Steele]

And, of course, there's the underwater telephone for communication between submarines. IIRC the nickname for it is the Gertrude and it's pretty primative and often a bit like trying to have a conservation on a very bad phone line, but it does work.


:k_rofl:

It sounds very much like two cans on a piece of piano wire.

[CaptBones]

Yeah...but without the wire!:har:

[Dallsim]

So many thorough replies so it will take a while to respond to all. I will start by replying and asking more questions to CaptBones and l02turner because I just happened to see “Das Boot” on Blu-ray with the girlfriend this weekend. What a phenomenal film!

The biggest difference was in the German “Wolfpack” method of operation. There, the gathering and concentration of units to attack a convoy was coordinated and controlled by the HQ Command ashore and that did depend on a steady stream of 2-way communication between the individual U-Boats and BdU. Unless detected by the enemy, the boats would travel to the designated intercept position on the surface and would get updated reports on the convoy and orders from HQ by Enigma-encrypted radio messages (good scenes of that in “Das Boot”). That turned out to be an Achilles heal though; radio direction finding equipment was finally installed aboard ships and aircraft as well as ashore and the ability of the Allies to detect and localize U-Boat transmissions was one of the factors in defeating the wolfpacks.

A: That is a story in itself. Google “Enigma” and see what comes up; by all means see the movie “The Imitation Game”.

Ya'll probably know this but the Germans had a weakness when it came to communications - the allies broke the code pretty early and I believe it was Sub overall commander Doneitz who required all subs to report their position on a daily basis

At the very beginning of the film, it was stated that, despite Hitler clearly knowing that the German naval fleet had no chance in surviving against the Allies, he kept sending the submarines into their deaths. The Captain questioned numerous times how the Allies were miraculously able to “anticipate” the whereabouts and attacks of the German submarines. The story takes place in 1941 and I assume Enigma was cracked without the Germans being aware?

If I remember “The Imitation Game” correctly, the Allies purposely sacrificed some of their own convoys in order to not raise too high a suspicion that Enigma had been decrypted. In Das Boot, when the submarine manages to take out two ships while firing at four, they lose track of the Destroyer’s position, leading to the submarine being taken by a surprise attack from another direction. Would you believe this to be a calculated sacrifice, or some form of misdirection by the Allies in order to lure the submarine into a vulnerable position?

In the future, there's a lot of talk about laser based communications, a bit like fiber optics but through the water rather than a fibre tube.

After checking the link provided by Oberon, I became intrigued to read more about Laser Communication and learnt of a new term called “Quantum Key Distribution” (QKD), a new method for secure communication. This technology behaves based on quantum mechanics and takes advantage of light, or laser light to be more specific. Apparently, QKD produces a shared secret key, which is randomly made, to two parties who will use it to encrypt and decrypt the messages they send and receive. If somebody were to eavesdrop or try to read the key, the attributes of the key will be altered and you would instantly know that the key has been tampered with. I.e., once read, it’s known. The key would be discarded and a new would be sent and only used if it remains untouched.

Imagine if the Germans had a similar type of device back then? I assume submarines nowadays are looking to take advantage of laser communication so that they can stay deep under water and remain undetected while still being able to communicate with the world above sea level?

The topic of Enigma QKD actually got my thinking about which similar security measures are in place today in order to make sure our daily conversations stay private. After some digging, I discovered that there are methods to encrypt communication such as emails with something known as SSL (Secure Sockets Layer) and TLS (Transport Layer Security). There was this one site which features a few guides giving a great introduction to how you can send emails securely:
https://www.1and1.co.uk/digitalguide/e-mail/e-mail-security/email-encryption-with-ssl/

Not sure how comparable it is to Enigma, but digital guide explains that, when we send emails without encrypting them, they are sent as plain text and can be easily intercepted and read while underway to the proper recipient. By sending emails using TLS or SSL, the email will be encrypted and cannot be deciphered by “third parties” due to the fact that they do not have access to the key that is needed to decrypt the message.

It also looks as though many email clients seem to offer this encryption feature in the settings, which you can turn on and off yourself. When I think of it, I am not sure if I have enabled mine yet but will have an immediate look right after posting :). Another bonus listed for the use of SSL and TLS seem to be with securing data transmission on websites if important and private information is shared.

I hope the future makes use of Quantum Key Distribution. The great advantage I find with it is the ability to identify any eavesdropping or tampering of the key. I wonder if submarines will be the first to incorporate this technology, while the public still has to wait quite a while before it becomes the norm :)

Anyhow, will get back to other people’s post later. Too much to ask!

[CaptBones]

Q. The story takes place in 1941 and I assume Enigma was cracked without the Germans being aware?

A. Yes. Take a look at uboat.net, under the "Technolgies" tab, for a thorough explanation.

Q. Would you believe this to be a calculated sacrifice, or some form of misdirection by the Allies in order to lure the submarine into a vulnerable position?

A. Neither. It's a filmmaker's presentation of an attack on a convoy...very accurate (Heinrich Lehmann-Willenbrock was a technical advisor), but still a theatrical version of a submarine attack on a convoy. Give it a try yourself in Silent Hunter 3...start with the stock version, then try some MODs like Living Silent Hunter 3 and/or GWX3. Good luck.

[Dallsim]

Some great information on uboat.net. The ultimate site for German submarine info :) A lot to digest.

Back to the film, I cannot forget the scene when the submarine goes under after losing control, sinking towards the maximum threshold before collapsing. I now read on Wikipedia that the "crush depth" for the U-96 at the time was somewhere between 250 and 295 meters. While watching, I had no idea how many meters could be sustained, and I wonder if the crew knew of any specific crushing treshold as well. My heart was pumping, to say the least! Was this type of information transparent? In the Film, they test the submarine at the beginning. Is this normal behaviour or once more made for dramatical effects?

Exciting to read that they are making a TV serie sequel to Das Boot, which will be released in 2018. 8 episodes lasting an hour each. Now that they cannot rely on Heinrich Lehmann-Willenbrock for authenticity, who will they turn to in order to ensure that submarine experts like yourselves won't have a "hissy-fit" when watching :)

[CaptBones]

There's also uboatarchive.net...check it out as well.

"Crush depth" is a calculated value; nobody has ever returned to tell of the actual crush depth that their boat experienced. Given the safety factor used in designing and constructing the hull, crush depth could be anything between two and four times the test depth...even more. In practice, it might be substantially less than the calculated value...age, corrosion, wear and tear, undiscovered damage, all would contribute to that.

Yes, it was somewhat "transparent", the crew would know what the test depth and crush depth were; they would most likely have dived to test depth at least once, during final Sea Trials or Acceptance Trials. In wartime they would most likely have gone to test depth, and deeper, on more than one occasion. After every "overhaul" or regular inport maintenance/upkeep period, you would make at least one dive to test depth to verify that everything had been put back together correctly. In wartime, an astute skipper would push that test dive beyond Test Depth, at least 1-1/2 times as deep, twice if they had strong confidence in the engineers and builders.

If you can get your hands on a copy of Dick O'Kane's book "Clear the Bridge!", he treats the subject of Test Depth well in Chapters 1 and 2 and goes on with real-world applications while on patrol, several more times.

We...or rather some of us ,"experts" will always have "hissy-fits" when it comes to movies (and games) about submarines and submarine warfare. I think we're all "rivet-counters" (with apologies to my fellow model railroaders as well) and all prone to expect the impossible from anyone who dares to produce something that is an "authentic" recreation of a world that you can't recreate or duplicate 100% on a screen (big or little).

BTW...I'll share my definition of "expert" with you; an "ex" is a has-been and a "spurt" is a leak under pressure. One should never let it go to their head.:O: