Is depth charge used in a patrol aircraft?

This new stand alone release based on the legendary War in the Pacific from 2 by 3 Games adds significant improvements and changes to enhance game play, improve realism, and increase historical accuracy. With dozens of new features, new art, and engine improvements, War in the Pacific: Admiral's Edition brings you the most realistic and immersive WWII Pacific Theater wargame ever!

Moderators: wdolson, MOD_War-in-the-Pacific-Admirals-Edition

User avatar
wdolson
Posts: 7690
Joined: Tue Jun 27, 2006 9:56 pm
Location: Near Portland, OR

RE: Is depth charge used in a patrol aircraft?

Post by wdolson »

ORIGINAL: crsutton

TBF avenger could carry four DC. Late war they might have two 500 pound DC and a homing torpedo. The PBY liberator carried more but doctrine generally called for DC to be dropped in a four charge pattern so it did not matter too much. Basically the aircraft was only going to get one chance to attack. Once CVEs were in number the Avengers were more effective due to numbers and time over target. Avengers are credited with sinking "35" U boats. I could not locate numbers for Japanese subs but you can see that they were very effective. An effective aerial sub attack required the element of surprise to be effective. The sub had to be on the surface or just beginning to submerge. Once the sub was underwater the success rate dropped off dramatically. (Homing torpedoes boosted that a bit but you won't see them in the game either). DC attack from the air eventually became highly refined (credit the Brits) and were based on very good statistical analysis.

I see no reason to fool with the game as it works now. Consider the bombing to be an abstracting that reflects the multifaceted aspect of attacking subs. You can read this report about wildcats and avengers attacking subs from the USS Card. It was usually a bit more complex than just a bombing run. In this case the subs were suppressed with strafing, then bombed and then depth charged-a complexity that just cannot be modeled in the game.


https://books.google.com/books?id=-ivBo ... er&f=false

See the link I posted above, it has the cause of every Japanese sub sinking listed by date. Aircraft accounted for fewer subs in the Pacific, but I think it was due to the nature of the types of TFs. The Atlantic was mostly Allied merchant TFs with the occasional warship TF. In the Pacific, the Allied TFs were a higher percentage warships. Warships TFs can have more escorts, especially carrier TFs, and warships are usually faster than merchant ships. If a sub was detected, the escorts would work it over while the other ships got out of there at high speed.

Japanese sub doctrine was also very different from German sub doctrine. The u-boats were hunting merchant ships from the start. The Japanese doctrine was to deploy their subs ahead of the warships to thin out enemy warships before a big battle. Later when the warships were not going to sea much, a lot of their subs were tied up moving supplies to bypassed bases. The Japanese did some ship hunting without the main fleet coming, but it was nowhere near as common as it was with US and German sub doctrine.

Bill
WIS Development Team
User avatar
geofflambert
Posts: 14887
Joined: Thu Dec 23, 2010 2:18 pm
Location: St. Louis

RE: Is depth charge used in a patrol aircraft?

Post by geofflambert »

ORIGINAL: AW1Steve

ORIGINAL: geofflambert

Ooh, I just had a wicked idea. I like to go back in time and fix things. How about an ASW weapon which would consist of two bombs connected by a chain. They would have magnetic exploders (maybe). The trick would be to bracket the front end of the sub if it was shallow enough that you could see it. The bombs would have some sort of fins so that when the chain snagged on something on top of the sub the bombs would rise and close with the sub (assuming the sub was moving forward). I should've worked for DARPA. Naaah.


And I assume the bombs will be made out of plastic or concrete? So that they each don't cause the others magnetic exploder (which certainly did not work in torpedos) to blow each other up? Or the plane carrying them? [:D]


You obviously are completely unfamiliar with personal magnetism.

User avatar
geofflambert
Posts: 14887
Joined: Thu Dec 23, 2010 2:18 pm
Location: St. Louis

RE: Is depth charge used in a patrol aircraft?

Post by geofflambert »

ORIGINAL: Chickenboy

ORIGINAL: geofflambert

In reality, damaging or sinking a sub with one or two depth charges would be like winning the powerball. PBYs could and did carry them. I can't imagine that aircraft carriers would have them in inventory, certainly not fleet carriers. I don't know what went on in the Atlantic, though. All they would be good for is door knockers, letting the sub know to keep underwater and deep. Catching them on the surface is what you want ideally, and bombs would be best for that. In the end, I doubt the game will reward you for having depth charges available, and if I were the coder I might consider penalizing you. A problem with patrol aircraft carrying depth charges is if they encounter enemy surface units. I imagine you'd be cussing yourself (the pilot) out about 'why did I have them load depth charges?' One more thing, concerning carrier aircraft: how are they going to set the depth on the charge? Not that you brought that up, I just thought I'd cover that.

It was very difficult to hit a submarine directly with a bomb fused for a surface target. "Depth bombs" were set to explode at a depth, but were still not as effective as ye olde depth charge per se.

Your characterization is exactly 180 degrees separated from the reality of the situation in the Atlantic. A bomb run was unlikely to meet with success. A depth charge attack on a surfaced or recently submerged submarine was devastating-the DCs would be set for shallow triggering and were ghastly. Read Blair's Hitler's U-boat War for further information.

You're presuming I can read. I have an assistant for that and he doesn't know what you're talking about. I will leave the matter there, and being a gentleman, I'm sure you will too. [:'(]

Alfred
Posts: 6683
Joined: Thu Sep 28, 2006 7:56 am

RE: Is depth charge used in a patrol aircraft?

Post by Alfred »

Hadn't thought it possible for a Gorm to be a gentleman.
 
On the other hand the promise to "be merciful and swift" is exactly the sort of kind consideration expected from a "gentleman".
 
Alfred
User avatar
geofflambert
Posts: 14887
Joined: Thu Dec 23, 2010 2:18 pm
Location: St. Louis

RE: Is depth charge used in a patrol aircraft?

Post by geofflambert »

ORIGINAL: Alfred

Hadn't thought it possible for a Gorm to be a gentleman.

On the other hand the promise to "be merciful and swift" is exactly the sort of kind consideration expected from a "gentleman".

Alfred

I was referring to Chickenboy. I am certainly no gentleman. And don't capitalize gorn unless you're referring to the planet, Human.

Cavalry Corp
Posts: 4308
Joined: Tue Sep 02, 2003 5:28 pm
Location: Sampford Spiney Devon UK

RE: Is depth charge used in a patrol aircraft?

Post by Cavalry Corp »

Note how many Jap subs were killed by allied subs - not sure we would see anything like that in the game?
User avatar
Chickenboy
Posts: 24648
Joined: Fri Jun 28, 2002 11:30 pm
Location: San Antonio, TX

RE: Is depth charge used in a patrol aircraft?

Post by Chickenboy »

ORIGINAL: geofflambert

ORIGINAL: AW1Steve

ORIGINAL: geofflambert

Ooh, I just had a wicked idea. I like to go back in time and fix things. How about an ASW weapon which would consist of two bombs connected by a chain. They would have magnetic exploders (maybe). The trick would be to bracket the front end of the sub if it was shallow enough that you could see it. The bombs would have some sort of fins so that when the chain snagged on something on top of the sub the bombs would rise and close with the sub (assuming the sub was moving forward). I should've worked for DARPA. Naaah.


And I assume the bombs will be made out of plastic or concrete? So that they each don't cause the others magnetic exploder (which certainly did not work in torpedos) to blow each other up? Or the plane carrying them? [:D]


You obviously are completely unfamiliar with personal magnetism.

You are right. Where can we sign to have you attached to explosives and dropped from aircraft, gorn? [:'(]
Image
User avatar
Lecivius
Posts: 4845
Joined: Sun Aug 05, 2007 12:53 am
Location: Denver

RE: Is depth charge used in a patrol aircraft?

Post by Lecivius »

ORIGINAL: Chickenboy

ORIGINAL: geofflambert

ORIGINAL: AW1Steve




I can take care of that. Let me get to my transporter...


And I assume the bombs will be made out of plastic or concrete? So that they each don't cause the others magnetic exploder (which certainly did not work in torpedos) to blow each other up? Or the plane carrying them? [:D]


You obviously are completely unfamiliar with personal magnetism.

You are right. Where can we sign to have you attached to explosives and dropped from aircraft, gorn? [:'(]
If it ain't broke, don't fix it!
User avatar
crsutton
Posts: 9590
Joined: Fri Dec 06, 2002 8:56 pm
Location: Maryland

RE: Is depth charge used in a patrol aircraft?

Post by crsutton »

ORIGINAL: wdolson

ORIGINAL: crsutton

TBF avenger could carry four DC. Late war they might have two 500 pound DC and a homing torpedo. The PBY liberator carried more but doctrine generally called for DC to be dropped in a four charge pattern so it did not matter too much. Basically the aircraft was only going to get one chance to attack. Once CVEs were in number the Avengers were more effective due to numbers and time over target. Avengers are credited with sinking "35" U boats. I could not locate numbers for Japanese subs but you can see that they were very effective. An effective aerial sub attack required the element of surprise to be effective. The sub had to be on the surface or just beginning to submerge. Once the sub was underwater the success rate dropped off dramatically. (Homing torpedoes boosted that a bit but you won't see them in the game either). DC attack from the air eventually became highly refined (credit the Brits) and were based on very good statistical analysis.

I see no reason to fool with the game as it works now. Consider the bombing to be an abstracting that reflects the multifaceted aspect of attacking subs. You can read this report about wildcats and avengers attacking subs from the USS Card. It was usually a bit more complex than just a bombing run. In this case the subs were suppressed with strafing, then bombed and then depth charged-a complexity that just cannot be modeled in the game.


https://books.google.com/books?id=-ivBo ... er&f=false

See the link I posted above, it has the cause of every Japanese sub sinking listed by date. Aircraft accounted for fewer subs in the Pacific, but I think it was due to the nature of the types of TFs. The Atlantic was mostly Allied merchant TFs with the occasional warship TF. In the Pacific, the Allied TFs were a higher percentage warships. Warships TFs can have more escorts, especially carrier TFs, and warships are usually faster than merchant ships. If a sub was detected, the escorts would work it over while the other ships got out of there at high speed.

Japanese sub doctrine was also very different from German sub doctrine. The u-boats were hunting merchant ships from the start. The Japanese doctrine was to deploy their subs ahead of the warships to thin out enemy warships before a big battle. Later when the warships were not going to sea much, a lot of their subs were tied up moving supplies to bypassed bases. The Japanese did some ship hunting without the main fleet coming, but it was nowhere near as common as it was with US and German sub doctrine.

Bill


Thanks Bill, I missed your link. Allied subs did sink quite a few. I am guessing it is because they had radar and most likely got the tactical advantage over Japanese subs more often than not.

Interesting to see how effective DEs became as the war progressed. I recall reading about the England, all six of her kills were achieved exclusively with hedgehogs. In fact only in one of the six separate actions were depth charges used ( and only just once) by any of the ships taking part. The hedgehog had made depth charges virtually obsolete because depth charges which always exploded under water would disrupt the ability of sonar operators to maintain constant fixes. Skilled crews using advanced sonar could fix a Japanese sub and never lose contact when using hedgehogs because the hedgehogs only exploded when they actually hit a sub. Yet in the game I have never seen mousetraps or hedgehogs do much. Guess you have to look at that as an abstraction. Allied DC are pretty deadly in the end.
I am the Holy Roman Emperor and am above grammar.

Sigismund of Luxemburg
User avatar
Barb
Posts: 2503
Joined: Tue Feb 27, 2007 7:17 am
Location: Bratislava, Slovakia

RE: Is depth charge used in a patrol aircraft?

Post by Barb »

I suppose the Hegehog/Mousetrap/Squid works as "damaging" content of the ASW attack, while the "killing" part is done by the regular DCs in game.
Those ASW mortars do not carry big punch, but are highly accurate - thus few hits will damage the sub sufficiently to be effectively targeted by less accurate and more deadly DCs...

High portion of japanese subs sunk by subs was also thanks to the allied Ultra/Sigint interceptions... Knowing an enemy sub will transit an area at given date and time it is easy to send one of your own subs to intercept... USS Batfish (SS-310) claimed RO-115 on 10 February 1945 (some conflicting claims here), RO-112 on 11 February 1945 and RO-113 on 13 February 1945...
Image
User avatar
Lowpe
Posts: 24582
Joined: Mon Feb 25, 2013 2:25 pm

RE: Is depth charge used in a patrol aircraft?

Post by Lowpe »

From the Japanese side of things:

The Japanese also developed air-deliverable depth bombs. The Navy Type 99 Model 6 Mark 2 was a 132 lb (60 kg) weapon with a kill radius of about 12 feet (4 m). It was the usual weapon carried by aircraft on routine patrol. The Type 1 Model 25 Mark 2 was 551 lb (250 kg) weapon with a kill radius of about 33 feet (10 m) that was normally loaded only when a target was already located by surface ships or another aircraft. There was also a experimental Type 19 Model 25 Mark 2 of 398 lbs (180 kg) weight and with a kill radius of 25 feet (8 m), which was intended for the Q1W "Lorna" and other aircraft with magnetic anomaly detectors. All of these depth bombs used timed fuses corresponding to various estimated depth settings. The Type 15 fuse could set for any depth up to 50 feet (15m), though the selection had to be made when the bomb was loaded on the aircraft. Other fuses were preset for 80, 150, or 300 feet (26, 46, or 91m). The last corresponded to a time delay of 17 seconds.
spence
Posts: 5421
Joined: Sun Apr 20, 2003 6:56 am
Location: Vancouver, Washington

RE: Is depth charge used in a patrol aircraft?

Post by spence »

On 14 May a Catalina of the US Navy attacked and destroyed a U-boat; this was either U-657[3] or U-640.[4] On 13 May Liberator B/86 had attacked a U-boat with a FIDO, but this vessel, U-456,[5] was only damaged, sinking the following day from damage received. One of these vessels was the first U-boat sinking achieved using FIDO. During its career, the torpedo sank a total of 37 submarines, achieving an effectiveness of about 22%, compared with about 9% for depth charges.

from US Navy OEG Study No. 289, 12 August 1946 provides the following data related to Mark 24 effectiveness:
Number of attacks in which Mark 24s were launched 264
Total number of Mark 24 torpedoes launched - all targets 340
Number of Mark 24s launched against submarines 204
Number of Mark 24 attacks on submarines by US aircraft 142
Number of Mark 24 attacks by Allied (primarily British) aircraft 62
Number of German U-boats sunk by FIDO 31
Number of German U-boats damaged by FIDO 15
Number of Japanese submarines sunk by FIDO 6
Number of Japanese submarines damaged by FIDO 3
Total number of submarines sunk by FIDO (German & Japanese) 37
Total number of submarines damaged 18
General characteristics

Diameter: 19 inches (46 cm).
Length: 84 inches (2.13 m).
Weight: 680 lb (308 kg).
Warhead: 92 lb (41.7 kg) HBX high explosive.
Propulsion: 5 hp (3.7 kW) electric motor driving a single propeller, powered by a 48 volt lead acid battery.
Speed and endurance: 12 knots for 10 minutes, giving a range of about 4,000 yards (3,700 m)
Homing system: 4 piezoelectric hydrophones operating at 24 kHz and vacuum tube signal processing system with proportional steering.
Maximum drop altitude: 200 to 300 ft (60 m to 90 m)
Maximum aircraft launch speed: 120 knots (220 km/h).

So 9 Japanese subs were destroyed by FIDO's. Although that seems like a small number in the Pacific the ratio of aircraft attributed kills to surface ship attributed kills much much less (probably because of the size and geography of the Pacific compared to the Atlantic).

Technically it was called a mine but it behaved like a torpedo. It is not included in the game even though on average it was 2 and 1/2 times as effective as depth charges.

Always remember that this is only a game and we MUST MUST MUST give the Japanese Player a chance to change history (improved ASW) even if it means discounting Allied tactical counter-developments (Mark 26 anti-escort torpedo) and their own improvements in ASW. That way the Japanese can park their subs 1 hex away from your airbases and almost never worry about air attack. German experience to the contrary doesn't count.


User avatar
Lowpe
Posts: 24582
Joined: Mon Feb 25, 2013 2:25 pm

RE: Is depth charge used in a patrol aircraft?

Post by Lowpe »

ORIGINAL: spence
That way the Japanese can park their subs 1 hex away from your airbases and almost never worry about air attack. German experience to the contrary doesn't count.

When I try that, I get a sunk Iboat, or at best a heavily damaged one. Only safe to do if no planes are flying ASW.
wegman58
Posts: 460
Joined: Sat Dec 28, 2013 1:15 pm
Location: Edina, MN (FROM the Bronx)

RE: Is depth charge used in a patrol aircraft?

Post by wegman58 »

ORIGINAL: spence
On 14 May a Catalina of the US Navy attacked and destroyed a U-boat; this was either U-657[3] or U-640.[4] On 13 May Liberator B/86 had attacked a U-boat with a FIDO, but this vessel, U-456,[5] was only damaged, sinking the following day from damage received. One of these vessels was the first U-boat sinking achieved using FIDO. During its career, the torpedo sank a total of 37 submarines, achieving an effectiveness of about 22%, compared with about 9% for depth charges.

from US Navy OEG Study No. 289, 12 August 1946 provides the following data related to Mark 24 effectiveness:
Number of attacks in which Mark 24s were launched 264
Total number of Mark 24 torpedoes launched - all targets 340
Number of Mark 24s launched against submarines 204
Number of Mark 24 attacks on submarines by US aircraft 142
Number of Mark 24 attacks by Allied (primarily British) aircraft 62
Number of German U-boats sunk by FIDO 31
Number of German U-boats damaged by FIDO 15
Number of Japanese submarines sunk by FIDO 6
Number of Japanese submarines damaged by FIDO 3
Total number of submarines sunk by FIDO (German & Japanese) 37
Total number of submarines damaged 18
General characteristics

Diameter: 19 inches (46 cm).
Length: 84 inches (2.13 m).
Weight: 680 lb (308 kg).
Warhead: 92 lb (41.7 kg) HBX high explosive.
Propulsion: 5 hp (3.7 kW) electric motor driving a single propeller, powered by a 48 volt lead acid battery.
Speed and endurance: 12 knots for 10 minutes, giving a range of about 4,000 yards (3,700 m)
Homing system: 4 piezoelectric hydrophones operating at 24 kHz and vacuum tube signal processing system with proportional steering.
Maximum drop altitude: 200 to 300 ft (60 m to 90 m)
Maximum aircraft launch speed: 120 knots (220 km/h).

So 9 Japanese subs were destroyed by FIDO's. Although that seems like a small number in the Pacific the ratio of aircraft attributed kills to surface ship attributed kills much much less (probably because of the size and geography of the Pacific compared to the Atlantic).

Technically it was called a mine but it behaved like a torpedo. It is not included in the game even though on average it was 2 and 1/2 times as effective as depth charges.

Always remember that this is only a game and we MUST MUST MUST give the Japanese Player a chance to change history (improved ASW) even if it means discounting Allied tactical counter-developments (Mark 26 anti-escort torpedo) and their own improvements in ASW. That way the Japanese can park their subs 1 hex away from your airbases and almost never worry about air attack. German experience to the contrary doesn't count.



You need to go down the page some, but NavWeaps tends to be pretty good:

http://www.navweaps.com/Weapons/WTUS_WWII.htm

Bill Goin
Post Reply

Return to “War in the Pacific: Admiral's Edition”