Actually, depth charges were the most widely used ASW weapon in WWII, and if you used them right, they'd work very nicely. In fact, the US Navy in WWII very carefully studied things like search patterns, size of areas that could productively be patrolled, which depth charge patterns were most effective, etc. Another thing is that depth charges were not the weak little firecrackers that you see in the movies. In movies like this, Run Silent, Run Deep, and others, you see depth charges going off ten feet from the boat, and maybe the boat keels over for a moment. In reality, there's two or three hundred pounds of high explosive in each of those charges. If a REAL depth charge went off that close to your boat, your ass was fish food. Those big splashes on the surface when they went off? Water conducts the energy of the explosion much better than air does. That's actually what it looks like on the surface when a depth charge goes off three hundred feet down.
Another thing is that most torpedoes at that time were unguided beyond simple depth control mechanisms. I don't recall exactly, but I don't think the first homing torpedoes were fielded until 1943-44ish, and those were simple homing torpedoes with microphones in the nose, which homed in on the loudest noise they heard. They weren't the kind of targetable, retargetable weapons we have today. And because they'd home in on any noise they heard, any ship or submarine that fired one had to stop its engines first. Not a good situation to be in if there's someone else coming after you. I'm not sure, but I think a lot of those homing torpedoes might have been air-dropped, because then you don't have the problem of the torpedo potentially homing on its launching vessel.
And the black stuff coming out of the sub was fuel oil being dumped to sea, making a slick that could confuse the destroyer's sonar.
When a loose cannon flogs a dead horse, there's the Devil to pay!
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Clemencedane
11 years ago
Thank you so much for that detailed and highly knowledgeable explanation. I think it may just be the way they filmed it that made the depth charges seem so ineffective. Or perhaps it was just the parts I watched. They all seemed to go so wide of the mark.
In other films about WWII submarine warfare I have enjoyed, like Das Boot and Below, we are looking through the eyes of the protagonists on the submarine and the depth charges are absolutely terrifying. Each time another one is fired from a ship on the surface not only is the whole sub crew stock still, holding their breath silently while they wait to see if they will be hit, but I found myself holding my breath as well. I could see the terrible power of the depth charges in a way that was utterly gripping. In this film they just didn't seem to be able to aim them very well, perhaps because they did not have a good sonar picture on where the sub was.
I thought the black stuff was oil, but it also seemed they were releasing it deliberately (as opposed to a puncture in the tank) so your explanation confirms that. I was thinking it was almost like an octopus defense!
It's true most of my understanding of torpedoes comes from Tom Clancy novels and these are clearly from a much more recent stage of torpedo design and capability.
Thank you for giving me such an informed perspective.
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fskpilot
11 years ago
You're welcome. There's definitely some cinematographic license taken in these movies. You have to show the depth charges being that close, or the audience may not perceive the danger of it.
There's also the fact that the exact timing of the release of a depth charge pattern was still more art than science, because the destroyer loses sonar contact as it passes over top of the sub, it takes time for the charges to sink to depth (early or late release, charges set too deep or too shallow = miss), and the destroyer captain really only has his sonar operator's best guess as to what depth to set his charges for in the first place. And all the operator really has to work with is a set of ear phones, a microphone, and a dial to tell him which direction his microphone is pointed, and thus where the sound is coming from. They didn't have any of those fancy displays and computers to help them like they did in The Hunt for Red October.
Das Boot really did a good job of showing what a terrifying experience it was to be on a U-boat under attack. They could hear the destroyer coming and hear the splashes of the "wasserbombs", and there was very little they could do about it. They couldn't outrun the destroyer, shooting the destroyer on its attack run would take far too long to set up, and trying to outmaneuver the destroyer would be pointless because the destroyer would still be able to track them. You could try to dive under the eggs, or you could go silent and try to lose him that way (but if you were being pinged that was pointless), or you could release oil to try and confuse his sonar, but really all you could do was wait and pray to God that none of those ash cans had your number on it today. And Das Boot especially does a terrifyingly good job of showing how hard it can be, waiting to live or die.
Try reading RAdm Samuel Eliot Morison's book, "The Two-Ocean War". It's a rather goood one-volume condensation of the battle history of the US Navy in WWII. Operations against German U-boats take up a fair portion of the book, and he neatly describes both the operational, educational, and technical progression that the Navy had to make in order to beat Adm. Doenitz and his boys.
When a loose cannon flogs a dead horse, there's the Devil to pay!
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Clemencedane
11 years ago
Thanks so much for that and the book recommendation. I will check it out.
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fskpilot
11 years ago
It's a good book. It's a nice compromise between a full-on history text and, say, a streamlined docu-drama like Tora! Tora! Tora! or Midway. Enjoy.
When a loose cannon flogs a dead horse, there's the Devil to pay!
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Locomotiva1
11 years ago
I have some doubt about the oil spill.
In most submarine movies, the emission of oil was basically a ruse to 'play dead'.
A spot of oil and some floating debrits surfaced to simulate a ruptured hull, so the destroyer would stop the attack - and wait, or run back to the convoy.
I'm not sure that any amount of oil in the water could 'spoof' any sonar, even the most rudimental ones in WWII.
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