damagelethality of depth charges

[DuckofTindalos]

Once the Mid-Atlantic Air Gap (aka the Black Hole) was closed by long-range aircraft, that was the end for the U-Boats. BTW, I'd always thought the FIDO wasn't that effective?

[rtrapasso]

ORIGINAL: Terminus

Once the Mid-Atlantic Air Gap (aka the Black Hole) was closed by long-range aircraft, that was the end for the U-Boats. BTW, I'd always thought the FIDO wasn't that effective?

Depends what you mean by "effective"... i think it had around a 25% kill rate, and they were pretty small so you could carry several in a bomber.

[Sardaukar]

ORIGINAL: Terminus

Once the Mid-Atlantic Air Gap (aka the Black Hole) was closed by long-range aircraft, that was the end for the U-Boats. BTW, I'd always thought the FIDO wasn't that effective?

From Uboat.net:

http://www.uboat.net/allies/technical/fido.htm

Number of MK24s launched against submarines 204
Total number of submarines sunk by FIDO (German & Japanese) 37*
Total number of submarines damaged 18

Not too bad, over 25 % hit rate.

[Nikademus]

FIDO wasn't particularily effective though it improved with time. Aircraft actually scored most of their kills/damage using conventional bombs.

To me, FIDO just added to the growing list of technological challenges facing the Uboats as time went by. But in the end, it was simply the presence of aircraft that was the decisive factor.

[Sardaukar]

True. FIDO was effective against subs that had time to crash dive and thus was making lot of propeller noise. Aircraft itself was deciding factor in that, indeed, no matter what kind of weapons it carried as long as effective.

[spence]

There is a old S&T mag out there somewhere with a table of how many U-Boats got killed by what combination of what....think it's the issue with the game "Wolfpack" in it.
In any case the sample of dead U-Boats is so large that even if surface ships alone only accounted for a third that's over 200 kills. 

[RUPD3658]

ORIGINAL: Terminus

Next he'll be lecturing us in his usual condescending tone that flak was ineffective as well

It knocked down only about 2% of attacking aircraft IRC. This may have been the numbers for attacking heavy bombers in WW2 but I recall using this stat (got it from someplace official) during a debate class in High School to show why the Star Wars missle defense system would not work.

[dtravel]

But I've also heard that AA was the defense most hated/feared by Allied bomber crews because there was absolutely nothing they could do about it.  They couldn't shoot back, they couldn't try to dodge it because they would be on their bomb runs and they could see it going off all around them.  In game terms that would equate to a morale hit even if few aircraft are damaged or destroyed.

[Speedysteve]

Agreed dtravel. The 8th crews HATED it. The only enemy they could not hit back at. Became even more pronounced into 44 when on most missions the LW did not interfere en masse and the number of flak guns employed increased. Politz alone had 220+ HAA[X(]

[Sardaukar]

That's why infantryman also hates both artillery and sniper fire. Both are very unnerving because there is usually not much to do to fight back, just try to take cover. Even worse in bomber plane vs. flak..cannot even do that.

[spence]

UBoat.net lists the causes of loss for German U-boats in WW2 as follows:

3 captured
35 to mines
43 to bombing in port
37 to combined operations of ships and aircraft
250 to aircraft alone while at sea
264 to ships alone (includes several sunk by merchant ship guns)
53 to unknown causes

Interesting in that one needs to combine the sunk by bombing in port with sunk by a/c at sea to exceed the number sunk by ships alone.  Personally I had thought that a/c sinkings exceeded ship sinkings of UBoats by a substantial margin.

Oops; didn't read to bottom of page: 32 more lost:

25 to accidents or friendly fire
4 taken over by Japan after German surrender
2 interned by Spain
1 sunk by SOVIET SHORE BATTERIES

[el cid again]

ORIGINAL: spence

Sub hulls are round - and are able to survive even a nuclear shockwave at remarkably short ranges! They simply reflect the wave

750 dead UBoats must be wrong!!!

At least you are consistent! Generally overlooking the significant data:

how many of those 750 UBoats were sunk by depth charges? How many by contact detonating weapons like Hedgehog? How many by torpedoes?
How many by mines? How many by bombs? How many by rockets? How many by gunfire hits? How many by a combination?

More significantly still, how many subs were ENGAGED with depth charges? While there is no way to answer the question, surely it is more than in any other campaign in history. The effectiveness of depth charges is dismal. Most escorts never damaged an enemy submarine - even if they engaged several or many times. [The great, glorious exception is USS England - of course - but note they don't often mention she had an entire task group including a CVE in attendence - and no one alleges she got them without using her Hedgehogs.]

[el cid again]

ORIGINAL: Terminus

ORIGINAL: ChezDaJez

Actually El Cid isn't far wrong this time. The outer hull was whatever shape the designers decided on but the pressure hull (inner hull) of most WWII submarines was round or oval shaped. Basically all the ballast piping and fuel cells were located between the hulls. Most designers did create somewhat oval outer hulls for improved seakeeping abilities when on the surface.
Chez

My problem is the "a submarine can withstand a nuclear pressure wave" claim...

If you are going to have a problem, at least don't chop of the qualifing clause from the sentence: - I didn't say at ANY range -
If you look at actual test data you will be impressed with how close you can be without doing structural damage to a submarine with a nuclear weapon. It is nothing like what you would expect. It is not the same thing as saying you won't get the sub if you are close enough - far from it.

Nevertheless, we had a problem with nuclear depth charges not being very effective. IF you could locate the target sub, you could use modern non-nuclear weapons with a high degree of effect. If you could not locate the target, firing nuclear depth charges didn't solve the problem. [There was the Russian concept of "sterilization" - fly heavy bombers on parallel courses - and drop a charge every so often - not so much because it would kill any subs as because it would surely render them deaf and unable to detect anything. But that is not what I am talking about. A trainee ordering use of a nuclear ASROC was a sure sign of a trainee in trouble. It wasn't going to work.]

[el cid again]

ORIGINAL: spence

I think the ASW routines are pretty good now.

Taken in isolation Cid's comments re ASW give the impression that ASW in WW2 was pretty ineffective. Close to 1000 dead axis subs from that conflict belie that contention. Yes, airplanes, mines, bombs, acoustic torpedos and accidents all killed some, perhaps the majority, but plain old depth charges killed a very statistically significant number. The same is very large, larger than any other class except merchies.

Spence has a remarkable ability to reason from conclusions: since he already "knows" the truth - he looks for reasons he must be correct. He does not consider the entire data set: the sheer number of submarines sunk, even by depth charges (if we allow it is large - which I will only for this point) - is in itself NOT an indication that a SINGLE depth charge is likely to kill a submarine - the topic under discussion. WHEN depth charges kill a submarine they virtually always do so due to CUMULATIVE damage - and one can never say "DC number 3 of salvo number 7 was the fatal one" - and could not even if one had perfect telemtry data on every attack in WWII. It is much more remarkable how LOW the chance is of a fatal hit is PER DC than it is true that they are effective weapons.

Note that I formally studied ASW in a USN school and served on a US destroyer with a secondary ASW mission - and even got to play with US and Soviet submarines on occasion. Anyone who thinks ASW is easy does not understand the subject! This was much worse in WWII. The greatest of IJN destroyer commanders - Takishi Hara - tells us of his first attack on a US submarine. The submarine is identified, and recorded his attack in its log. But his DCs were NOT fatal - and we can read the log because they were not - and his ASSUMPTION they MUST HAVE BEEN effective was flawed - based on an exaggerated (but still popular) view of DCs. It is quite normal not to be sure there is a target at all - and it is normal not to know what you did to the target - even today.

Note that US WWII ASW doctrine was not based on the concept of "kill enemy submarines." It was based on the concept of "get the escorted ships through" - a very different mission. If you could mess up the submarine's situation to the point it could not deliver torpedoes or mines effectively, you won - and you didn't have to sink it to do that. Only late in the war (see the case of USS England and its TF rolling up an entire patrol line in a week) was it possible to be aggressive in the sense implied by "one DC should be fatal." And even then, it was not true one DC had a good chance of inflicting fatal damage - but a TEAM of ships and planes using MANY DCs and other weapons did have a good chance.

[DuckofTindalos]

Who here has claimed that ASW is "easy"? The only one who's even used that word is you, cid, twice now...

[el cid again]

ORIGINAL: spence

UBoat.net lists the causes of loss for German U-boats in WW2 as follows:

3 captured
35 to mines
43 to bombing in port
37 to combined operations of ships and aircraft
250 to aircraft alone while at sea
264 to ships alone (includes several sunk by merchant ship guns)
53 to unknown causes

Interesting in that one needs to combine the sunk by bombing in port with sunk by a/c at sea to exceed the number sunk by ships alone.  Personally I had thought that a/c sinkings exceeded ship sinkings of UBoats by a substantial margin.

Oops; didn't read to bottom of page: 32 more lost:

25 to accidents or friendly fire
4 taken over by Japan after German surrender
2 interned by Spain
1 sunk by SOVIET SHORE BATTERIES

How have you managed to go from "a single DC should inflict fatal damage" to "all subs lost to surface ships were killed by DCs" as a meaningful position? Those same surface ships used guns, ahead throwing weapons and DCs, and note that DC patters of small numbers were so ineffective that huge patterns became the norm for the Allies.
IF DCs were normal - a Japanese PC with a pattern of 3 would be a nice ASW vessel. It ain't.

[spence]

In WitP there are "hits" a la combat report which seemingly cause cumulative damage and there are "hits" in the animation which seemingly show explosions on or immediately adjacent to the submarine.  One of those is should inflict catastrophic damage on the submarine, perhaps not fatal but a 'mission kill' anyways.  I do not dispute that it generally took a lot of depth charges thrown into the water to get the one that "hits". 
 
WitP does not (to my knowledge) allow escort types to finish off of a submarine which has been damaged by depth charges with gunfire or ramming (or by the crew scuttling a severely damaged boat.  Thus for the purposes of the game those "finishes" must be included in the "hits" caused by depth charges or other ASW weapons.  Reading throught the UBoat Fates Section at Uboat.net I noticed there did not seem to be any differentiation between killed by a depth charge or killed by a hedgehog.  It reports that the first hedgehogs were deployed in 1943 so I think it is safe to say that any uboat reported sunk by surface ships before '43 were killed outright using depth charges or so severely damaged by depth charges that they surfaced and were finished off with gunfire, ramming, torpedoes, or scuttling (all of which for game purposes would have to be included in depth charge hits).  The "Fates" section also lists the personnel casualties involved in the loss of each boat.  There is a strong correlation between boats lost with relatively light personnel losses and ones that were finished off by something other than depth charges.  "Lost with all hands" goes hand in hand with "sunk by depth charges from HMS/HCMS/USS...."
 
Of the Uboats reported sunk by ships (264), 22 were torpedoed by Allied submarines (mostly British).  Of the boats reported scuttled a like number reported scuttled were in fact scuttled after depth charge attacks so damaged them that they were unable to either fight, run or hide.  So the total of uboats effectively sunk by surface ships stays about the same.  And well over a hundred of those Uboats were killed by surface ship depth charges (with the aforementioned game qualifications about scuttling, gunfire etc) before 1943.   
 
 

[spence]

Some figures from the Pacific: DATA FROM IJN SUB TROMs at COMBINED FLEET

IJN subs sunk by surface warship alone (subs forced to the surface by ASW weapon damage and finished off with guns, torpedoes or ramming by the same surface ships are included (since WitP does not model this sequence of events - the number of such incidents is roughly 15 or about 25% of the total with more of the incidents relating to depth charge damage than hedgehog damage):

PRINCIPLE ASW WEAPON

DEPTH CHARGE - 44 KILLS

HEDGEHOG - 19 KILLS

MOUSETRAP - 1 KILL

There were three additional surface ship kills but the TROM did not specify what sort of weapon delivered the fatal attack. In one case there was no mention of weapons used; in the other 2 both depth charges and hedgehogs were used.

[Cmdrcain]

ORIGINAL: ChezDaJez


As far as the Falklands war goes, the Brits made a deliberate decision to attack any suspected submarine contact whether it was verified or not.
Chez

Wonder how many Large Fish, Dolphins, Whales, Sharks and such were shot....

[:D]

[ChezDaJez]

Wonder how many Large Fish, Dolphins, Whales, Sharks and such were shot....

Well, as someone who once "bombed" a disappearing radar contact (determined to be a whale a short while later) with active sonobuoys, I would say probably quite a few!

Torpedo suppository anyone?

Chez