Jump to content
You need to play a total of 5 battles to post in this section.
dmckay

A sub question...but not what you think!

24 comments in this topic

Recommended Posts

1,032
Members
4,725 posts
8,129 battles

I love sub movies.  Favorites are Das Boot (best ever), Run Silent Run Deep, and The Enemy Below. That said I have a question.  May need a sub expert here. Ok, in EVERY sub movie there is the obligatory depth charge attack scene. Every one!  Good drama for sure but I have an issue. Most of these depth charge attacks will have depth charges blowing up within like 10-20 yards of the sub....or closer it seems at times in a movie.  Sub crew gets tossed around, emergency lights come on, leaks happen, crew craps themselves, etc. Now seems to me if a depth charge or charges blow up that close to a sub that should be a dead sub but they survive these very close depth charge explosions in the movies. Is this Hollywood crap or could a WWII sub actually survive depth charge explosions going off as close as you see in these movies. Truth or just Hollywood drama? What WAS the kill zone for a depth charge blowing up near a sub in WWII?  Anyone know?  This is my key question.

Knew a guy who served in subs in WWII. He told me when I was a kid that lots of that is total B-Dung Hollywood crap. He survived these kinda attacks. Terrified him.

Edited by dmckay

Share this post


Link to post
Share on other sites
129
[LRM]
Supertester
550 posts
5,813 battles

A depth charge of approximately 100 kg of TNT (400 MJ) would normally have a killing radius (hull breach) of only 3–4 meters (10–13 ft) against a conventional 1000-ton submarine, while the disablement radius (where the submarine is not sunk but put out of commission) would be approximately 8–10 meters (26–33 ft).

Source: Wikipedia

Share this post


Link to post
Share on other sites
1,032
Members
4,725 posts
8,129 battles
1 minute ago, DonKarnage2 said:

A depth charge of approximately 100 kg of TNT (400 MJ) would normally have a killing radius (hull breach) of only 3–4 meters (10–13 ft) against a conventional 1000-ton submarine, while the disablement radius (where the submarine is not sunk but put out of commission) would be approximately 8–10 meters (26–33 ft).

Source: Wikipedia

Tks.  That surprises me.

Share this post


Link to post
Share on other sites
5,125
[SOUP]
Privateers, Modder
8,327 posts
8 minutes ago, dmckay said:

Tks.  That surprises me.

Water is a magical thing, both a cushion and a conductor of energy

  • Cool 1

Share this post


Link to post
Share on other sites
1,883
[RKLES]
Members
8,965 posts
10,828 battles

Yeah that is part of the reason they dumped several depth charges in sequences to get one close enough to do some damage. But even if a sub is put out of commission it can be about as good as destroyed since the crew would likely have to surface and surrender.

Share this post


Link to post
Share on other sites
1,032
Members
4,725 posts
8,129 battles
1 minute ago, Chobittsu said:

Water is a magical thing, both a cushion and a conductor of energy

This is true. But I will say a HELL of a lot of subs were killed in WWII. Germany lost something like 3/4 of all their subs.  Of course many were killed on the surface once the allies could find em with radar. U.S. lost a hell of a lot also.

Share this post


Link to post
Share on other sites
489
[SFBG]
[SFBG]
Members
1,599 posts
8,373 battles

You increased the chances of a successful hit by laying a long pattern over the suspected sub location. That's why many ships had those twin rails, for rolling them off the stern.

 

My dad's 3rd ship, a Fletcher-class destroyer primarily carried and used, a Hedgehog against subs...  https://en.wikipedia.org/wiki/Hedgehog_(weapon)

Slinging the charges in a wide circle cut down on the need for pinpoint accuracy, although advances in sonar technology toward the end of the war, led them to be pretty darn close to guessing where the sub was.

Share this post


Link to post
Share on other sites
1,032
Members
4,725 posts
8,129 battles
7 minutes ago, Admiral_Thrawn_1 said:

Yeah that is part of the reason they dumped several depth charges in sequences to get one close enough to do some damage. But even if a sub is put out of commission it can be about as good as destroyed since the crew would likely have to surface and surrender.

Allies got a German ultra (enigma) code machine from a sub that was forced to the surface.

Edited by dmckay

Share this post


Link to post
Share on other sites
1,883
[RKLES]
Members
8,965 posts
10,828 battles
3 minutes ago, dmckay said:

Allies got a German ultra (enigma) code machine from a sub that was forced to the surface.

Exactly and that one disabled U-Boat ended up being worth more than a thousand destroyed U-Boats since not only did they get the Enigma machine, but also the code books. And the German Naval codes were some of the last to be broken, due to the fact it had the most rotors in it thanks to Kriegsmarine leadership having been concerned about security.

Americans were heroic in boarding that sub to stop the scuttling so it could be captured.

  • Cool 1

Share this post


Link to post
Share on other sites
1,032
Members
4,725 posts
8,129 battles
7 minutes ago, OtterWolf said:

You increased the chances of a successful hit by laying a long pattern over the suspected sub location. That's why many ships had those twin rails, for rolling them off the stern.

 

My dad's 3rd ship, a Fletcher-class destroyer primarily carried and used, a Hedgehog against subs...  https://en.wikipedia.org/wiki/Hedgehog_(weapon)

Slinging the charges in a wide circle cut down on the need for pinpoint accuracy, although advances in sonar technology toward the end of the war, led them to be pretty darn close to guessing where the sub was.

Read your link.  Says by the end of the war 1 in 5 Hedgehog attacks resulted in a kill.  Not bad...not bad at all. No wonder that by the last 2 years of WWII going out to sea in a U-Boat was damn near a death sentence.

Share this post


Link to post
Share on other sites
1,032
Members
4,725 posts
8,129 battles
4 minutes ago, Admiral_Thrawn_1 said:

Exactly and that one disabled U-Boat ended up being worth more than a thousand destroyed U-Boats since not only did they get the Enigma machine, but also the code books. And the German Naval codes were some of the last to be broken, due to the fact it had the most rotors in it thanks to Kriegsmarine leadership having been concerned about security.

Americans were heroic in boarding that sub to stop the scuttling so it could be captured.

Did Admiral Donitz ever learn before he died that the Enigma codes were compromised?  I forget.  I know that was kept secret for a long time after the war. 

Share this post


Link to post
Share on other sites
1,883
[RKLES]
Members
8,965 posts
10,828 battles

Possibly not since many of these stories were hushed up until fairly recently and I heard a little of the code breaking papers are still classified, although some were able to be declassified recently.

Although think he might have suspected something about the codes being broken maybe.

Share this post


Link to post
Share on other sites
51
[OPEC]
[OPEC]
Members
79 posts
2,180 battles

Ha!  Gray Lady Down only has a collision with a (presumably) drunken Swedish freighter - no depth charges!

GLD.JPG

  • Cool 1

Share this post


Link to post
Share on other sites
1,032
Members
4,725 posts
8,129 battles
11 minutes ago, Admiral_Thrawn_1 said:

Possibly not since many of these stories were hushed up until fairly recently and I heard a little of the code breaking papers are still classified, although some were able to be declassified recently.

Although think he might have suspected something about the codes being broken maybe.

I read the book Spandau by Albert Speer who served 20 years in prison and of course knew Donitz well...he served 10 years with Speer..  He was clueless at that time. If I recall correctly he was rather mystified that he had lost so many subs. My have found out later before he died. I dunno. Died in 1980 at the age of 89. 

Edited by dmckay

Share this post


Link to post
Share on other sites
4,820
[GWG]
[GWG]
Alpha Tester, In AlfaTesters
19,770 posts
10,986 battles
1 minute ago, dmckay said:

I read the book Spandau by Albert Speer who served 20 years in prison and of course knew Donitz well...he served 10 years with Speer..  He was clueless at that time. If I recall correctly he was rather mystified that he had lost so many subs. My have found out later before he died. I dunno. 

Maybe but the Allies were so fearful of the German's figuring out that it had been compromised that they would let attacks through that they thought would tip them off, Coventry was one of those.

Killing the sub was not actually necessary as just keeping the sub from pressing its attack was actually almost as good as a kill.

Share this post


Link to post
Share on other sites
1,614
[HYDRO]
Members
3,006 posts
4,609 battles

Regarding ASW during WWII and not that much about depth charges, the Allies in the Atlantic were after the middle of the war very well equipped to deal with U-booten.  In addition to depth charges and radar, the British were using the Leigh Light for the final approach in attacks on U-booten that were charging their batteries at night. https://en.wikipedia.org/wiki/Leigh_Light

Supposedly,

Quote

Introduced in June 1942, it was so successful that for a time German submarines were forced to switch to charging their batteries during the daytime, when they could at least see aircraft approaching.

So you can imagine how hostile an environment in terms of countermeasures KMS U-booten were facing to justify such losses.

  • Cool 1

Share this post


Link to post
Share on other sites
4,820
[GWG]
[GWG]
Alpha Tester, In AlfaTesters
19,770 posts
10,986 battles
11 minutes ago, warheart1992 said:

Regarding ASW during WWII and not that much about depth charges, the Allies in the Atlantic were after the middle of the war very well equipped to deal with U-booten.  In addition to depth charges and radar, the British were using the Leigh Light for the final approach in attacks on U-booten that were charging their batteries at night. https://en.wikipedia.org/wiki/Leigh_Light

Supposedly,

So you can imagine how hostile an environment in terms of countermeasures KMS U-booten were facing to justify such losses.

Every man that went out on the U-Boats was a volunteer. In many ways it was a similar situation to WWI where becoming a pilot/aircrew and looking at a 2 week combat lifespan was a vast improvement over being in the trenches. The US sub force had the highest loss rate of all the combat forces too. Iron men in steel tubes all of them.

  • Cool 1

Share this post


Link to post
Share on other sites
1,032
Members
4,725 posts
8,129 battles
24 minutes ago, BrushWolf said:

Maybe but the Allies were so fearful of the German's figuring out that it had been compromised that they would let attacks through that they thought would tip them off, Coventry was one of those.

Killing the sub was not actually necessary as just keeping the sub from pressing its attack was actually almost as good as a kill.

Totally correct. 

Share this post


Link to post
Share on other sites
1,032
Members
4,725 posts
8,129 battles
7 minutes ago, BrushWolf said:

Every man that went out on the U-Boats was a volunteer. In many ways it was a similar situation to WWI where becoming a pilot/aircrew and looking at a 2 week combat lifespan was a vast improvement over being in the trenches. The US sub force had the highest loss rate of all the combat forces too. Iron men in steel tubes all of them.

I looked up the U.S. sub loses some time ago and it shocked me. I forget the figure. A bunch. 

I just checked.  52 subs lost. 1 out of 5. 

Edited by dmckay

Share this post


Link to post
Share on other sites
Beta Testers, In AlfaTesters
3,167 posts
9,567 battles

If you ever go to Pearl don't miss the Bowfin!  

Share this post


Link to post
Share on other sites
Alpha Tester
10,267 posts
4,608 battles

I've been on two subs in my life, the U505 in Chicago and the one that sat next to the Alabama. I'm not real claustrophobic but even as a kid both seemed so cramped and vulnerable. Very interesting to find out that depth charge info.

Share this post


Link to post
Share on other sites
3,770
[PSP]
Members
8,201 posts

If you have scubaed or know anything about the lateral line sense organ in fish, or perhaps have studied physics or remember something about your high-school science, then you will know that water is nearly non-compressible.  An explosion several meters away from a hull is not much different than one occurring right at the hull. This is why military and civilian divers who set charges have to be a long distance away before the charges go off. Amazingly, the data are scare and inconsistent as to exactly how far an underwater charge would be lethal to a diver but you would not find me anywhere within 300 meters of one.

https://www.researchgate.net/publication/283898513_Underwater_blast_injury_a_review_of_standards

I've been on the museum subs Nautilus and Pampanito. Both were well worth the trip.

Edited by Snargfargle
  • Cool 1

Share this post


Link to post
Share on other sites
1,032
Members
4,725 posts
8,129 battles
3 hours ago, Snargfargle said:

If you have scubaed or know anything about the lateral line sense organ in fish, or perhaps have studied physics or remember something about your high-school science, then you will know that water is nearly non-compressible.  An explosion several meters away from a hull is not much different than one occurring right at the hull. This is why military and civilian divers who set charges have to be a long distance away before the charges go off. Amazingly, the data are scare and inconsistent as to exactly how far an underwater charge would be lethal to a diver but you would not find me anywhere within 300 meters of one.

https://www.researchgate.net/publication/283898513_Underwater_blast_injury_a_review_of_standards

I've been on the museum subs Nautilus and Pampanito. Both were well worth the trip.

That is why I stated this thread. I knew NOTHING about all this. Just that in movies depth charges LOOKED like they should have killed that sub.  I want to thank all for responding. Just a great bunch of guys whom I will KILL given the opportunity. I will kill. I am rutherless. Ruthless......what ever. :Smile_honoring: U get it. Heh

Share this post


Link to post
Share on other sites
1,032
Members
4,725 posts
8,129 battles
4 hours ago, J30_Reinhardt said:

I've been on two subs in my life, the U505 in Chicago and the one that sat next to the Alabama. I'm not real claustrophobic but even as a kid both seemed so cramped and vulnerable. Very interesting to find out that depth charge info.

The one in Chicago is very neat. U-boat. Been there. Cramped as all hell.  There are very few real U-Boats on display in the world. Most where killed.  OR sunk after the war.  Of course Hitler made it to Argentina on one in the Spring of 1945. He is now in Bolivia with Elvis, JFK, Marilyn Monroe and assorted others. :Smile_glasses:

Edited by dmckay

Share this post


Link to post
Share on other sites

  • Recently Browsing   0 members

    No registered users viewing this page.

×