Every war movie I’ve seen with submarine warfare has scenes where the guys are whispering while trying to be undetected by the enemy.
Did whispering vs. talking really make a difference as to whether or not they were detected by enemy subs and/or enemy surface ships?
BTW, U-571 is pretty good war movie.
I’m non-military, so I have to defer to the squids on the board, but from what I understand, submarines (the modern ones, at least) run quietly enough that they can hear transient noise coming from inside another one at close range, including voices coming from inside.
Water, don’t forget, is an excellent conductor of sound energy.
even if the enemy can’t hear you, there has to be an incredibly strong psychological impulse to be as quiet as possible.
-ellis
Yeah, I was gonna say what Ellis said. Having everybody whisper reminds the crew to be quiet in more important ways, like not dropping wrenches, or drumming nervously on the bulkhead with spoons (I’ve never heard of that happening, but it would be bad if it did). I suppose it is a good way to remind new recruits how sound is everything (or nearly everything) in submarine warfare.
I heard of a story of a World War I German merchant submarine (!) which was being hunted in shallow waters around Britain. The Germans were on their way to the neutral U.S., and they were sitting on the bottom waiting for the RN to give up, so they sang, “We’ve rings on our fingers and bells on our toes!” I don’t know if there are German lyrics to that one, or if they sang in English. That’s not particularly relevant since WWI hydrophones were fairly primitive; I don’t even know if the British had them at that point (they got them in 1916?, and this story takes place in 1914 or -15?) I like the story anyway. Upshot: the Germans made it across the Atlantic, but submarines were never a significant part of the Kaiser’s merchant marine.
I asked Mr Lunasea (who is a submariner) and he says that it does make a difference. The listening capability of subs is amazing, and we all know how well sound travels through H20. When they call for quiet it pretty much means all movement & speaking ceases, as far as I know.
Boris said
A month ago I would have wondered whether submarines ever do rest on the bottom. Then I read a book about German U-boats in WWII in which it is mentioned several times that they rested on the bottom, especially when trying to hide from surface ships. I’d heard the myth that a sub resting on the sandy bottom would get stuck because of the pressure. I didn’t quite believe it, but I wasn’t sure. A little research turned up this site that explodes the myth.
Was passive sonar used in WWII? It seems that back then their listening techniques weren’t very refined. There were no helicopters in WWII to carry dipping microphones and I don’t recall naval ships having towed arrays back then either. Remember, your own ship is too loud to allow listening for anything useful if the hydrophone is glued to the keel (hence modern naval ships tow the hydrophone behind them). Also, I don’t think there was any such thing as sub vs. sub warfare in WWII. As a result subs themselves didn’t carry hydrophones of their own. They always came near the surface and checked things out with their periscope. Even if they could detect another sub they couldn’t hit it with anything other than the luckiest shot in the world (torpedos weren’t guided back then).
If this is so then talking on a sub in WWII would make little difference as no one is listening. What the destroyer on the surface is listening for is the return ping of their active sonar. The trick of sitting on (or near) the bottom was so the sub became part of the background and the destroyer couldn’t distinguish the sub from a rock or the sandy bottom.
Of course, today things are much different. As several people have already mentioned the hydrophones these days are VERY good. Talking on a submarine today could quite possibly get you into trouble. This must be the case if for no other reason than the navy goes to EXTREME lengths to make sure there are no noisy anything in a sub (all tools rubber coated, etc.). I doubt they’d go to all the trouble if there wasn’t a real concern of being heard.
I can’t say anything about WWII-era submarines, sonar, or hydrophones, but by the time I was in the Navy from 1989-1993 (admittedly on a surface ship) I knew that it does make a big difference. Submariners (or “bubbleheads” as they like to call themselves) even wear sneakers onboard, as opposed to the noisy hard leather workboots we wore on surface ships. Submarines do everything possible to minimize all kinds of noise.
And, as a tangentially-related fun fact, US Navy minesweepers obsessively minimize their magnetic signature, presumably to protect them from mines. Check it out:
A minesweeper’s hull is made of wood coated with fiberglass.
Its engine is made of non-ferrous metal.
Minesweeper crews go so far as to wear wooden belt buckles, and any bits of metal they may bring on board, like wedding bands or car keys, must be entered into a log upon boarding.
All this, despite the fact that most mines don’t work magnetically these days.
http://www.ob-ultrasound.net/hydrophone.html
http://www.uboat.net/allies/technical/asdic.htm
http://www.ukans.edu/~kansite/wwi-0699/msg00134.html
Those URLs should back up my contention that hydrophones have been used since 1916, at least aboard anti-submarine surface vessels. When they were first fitted to submarines, I don’t know.
The first one contains some weird claims, like hydrophones being used to detect icebergs. I mean, are icebergs really that noisy? So proceed with caution.
The third one is just a BBS message, but the writer seems like he know his stuff.
Yes Boris, icebergs are that noisy. Ice has a lot of shear lines that like to shift as the 'berg melts, and those shear lines creak quite loudly.
Sorry.
This just KILLED me.
I suddenly had a visual flash of everyone on the submarine being really quiet because there’s a British ship going by above, then one guy drops a wrench, and everyone jumps and goes SHHHHHHHHH!!! And then someone starts drumming nervously on the bulkhead with spoons, and everyone jumps and goes SHHHHHHHHHH!!! And then one sailor starts nervously to play the Sousaphone…
A real Monty Python moment.
Head down to the video shop and rent…
Run Silent, Run Deep
Destination, Tokyo
The Enemy Below
Everything you always wanted to know about WWII submarining.
“What is it sir ? I can’t make it out.”
Narile Thanks for the info. I remember hearing something on NPR where somebody tape recorded some pack ice. It was very creaky. So I guess it makes sense that icebergs are noisy; I just always assumed they were detected with active stuff.
Ike Let me guess, then the commanding officer comes down from the tower to figure out what all the fuss is about, gets angry, and draws his pistol, threatening to shoot the next guy who makes noise. The whole crew then looks really worried and shakes their head, fingers to lips.
Five The magnetic signature thing reminds me of speculation that the Soviet Alfa class submarines, with their titanium hulls, would be invisible to NATO magnetic anomoly detectors. I don’t know if there was enough ferrous metal inside them to trigger the MADs, and I don’t know if the titanium hulls were designed for that purpose, or for deep-diving capabilities. The Alfas were said to be able to make 40 knots.
How can you compile such a list and leave out Das Boot?!
Boris_B
Interesting links. While they do show that passive sonar was used it sounded nearly worthless and they relied much more on active sonar (pinging). The passive sonar, according to your links, needed fairly loud noises (machinery) and has to be relatively close to be of much use. I still doubt that talking would cause you to be caught in a WWII submarine.
I will say, however, that it’s probably human nature to be quiet when being hunted. Some primal leftover that tells us if a predator is near making a noise is probably a bad idea. Chances are good that whether or not talking was a bad idea I’d still probably keep my trap shut if a destroyer was lurking above.
And for the punch line, the camera pans up to reveal the highly unsuccessful British anti-sub ship, the H.M.S. Helen Keller:
“Any sign of enemy submarines?”
“What?”
“Huh?”
“Come again?”
“Did you just say sumfin’?”
From Boris B:
Actually, I’ve heard stories that scientists were actually able to translate the creaks and groans of a few North Atlantic icebergs into English:
A: “Hey, remember that big one Bob got in 1912?”
B: “snort haw haw haw…”
A: “Ssssh! Here comes another one.”
Thanks, Five, for mentioning “Das Boot” - I wanted to add it to the list, but didn’t know if the title had been translated.
Oh, and On-On right back at you (Last Boy Scout, H7, Germany).
Not too long ago I saw documentary done on a US sub on patrol. A few things I remember are:
They would go into silent mode and it was silent! Everyone not on active duty had to lie silently in his bunk. Everyone else was extremely silent!
They were listening to everything going on around them and sometimes it was whales and other natural stuff. The sounds were signature analyzed by computer to establish, origin, direction, distance etc. In spaite of everything it wa not always 100% clear.
There was a case of espionage a few years back when the russians got some info about how the USA makes their props so they are very silent, much more silent than Russian props are. This is very important as this prop noise allows sub detection.
In certain strategic places, like the straight of Gibraltar there are plenty of listening devices to track any subs passing.
Hey, all right! R U?
Where in Germany are you? My friend Little Sister (a man) just got back from Frankfurt.