Ok. Finally ADC Mod

[hopkins32]

Ok. Finally the Accurate Depth Charge is Historically Correct for the standard 300 pound DC. Here is some info on it.

At 8 to 10 m it will cause serious to fatal damage, Flooding Destroy engages , dive planes and so on .

At 25 to 30m light damage such as deck guns , flack guns radio antenna and so on.

For patch 1.4b only
Now up for download on my site at http://www.freewebs.com/subchallenge/

This is going into a realism mod im working on and I hope to have out within the next month or so. However to do it right this will take much time. I truly hate to mess with the Campaign_SCR and Campaign_RND files so if there is anyone who is good at this and would like to take part please contact me by PM or Email: jhopkins92@yahoo.com and ill send you the info on what I have now and what we will need. I'm also open to any input or suggestions your may have.

[Gizzmoe]

You want to make a realism mod with campaign changes and everything? Are you really sure that you want to reinvent the wheel??? ;)

[hopkins32]

You want to make a realism mod with campaign changes and everything? Are you really sure that you want to reinvent the wheel??? ;)

Its really not that hard to add historically correct data or events to the game , really just a matter of the research. :up:

[bobo]

hopkins, what Gizzmoe is trying to say is that there is/are mod(s) that already exist that contain historically correct data/fixes. . . . . . of course, some things are open to ones own interpretation I suppose. There is a big effort underway in the "Ops mod" (historical accuracy) and RUb-1.43 (another realism mod) contains the first beta of opsmod.

I do look forward to test drivin yer DC mod.

[hopkins32]

yeah i think your right bobo . I don't want to get into doing a project when there are already extremely good mods addressed this issue.

anyway the DC mod is up on my site :up:

http://www.freewebs.com/subchallenge/

[HW3]

I might be speaking out of turn here but, if you wanted to help on RUB or the OPS mod, you could contact Beery and he could put you in touch with the people doing it.

[CCIP]

Well I think the current position of beery and RUb on the whole DC thing is pretty different. I guess we're going by different data here; but generally speaking, DC's were a very ineffective weapon against uboats, which were further helped by their excellent double-hull design. And using surface-level effectiveness for a weapon that will usually be used against the boat when it's waay below isn't something I'd really agree with.

So in RUb, the wabos are indeed rather ineffective, which I agree with. There's a reason these weapons basically disappeared after WWII. Very few DC attacks (about 5% I believe) were successful, so the kill ratio per individual weapon (there'd be dozens of them dropped per attack) is very, very, very low.

However, an interesting mod, and it'll definitely add to the excitement. But I think DC settings in RUb are about right for realism on the whole, even if (much as with other things) they don't account for all possible factors. It's the survivability against them in the long run that counts.

[Col7777]

On reflection, although a different sim, in SH2 the DC's were deadly, and there was a mod to make them less effective.
So I suppose it is up to the individual, if he/she wants them then this mod is there for them.

[hopkins32]

CCIP , you make a vary interesting point but ill have to disagree with hear. I understand double-hull design and took it into consideration however it is not the super sub you may think , take in to account that sonar early in the war was not an extremely effective tool for determining an accurate depth of the sub so many DC's where dropped at deferent depths. Think about it a 300 pound DC at 200 feet in depth 20 feet away from you sub , what kind of shock wave is that ? Soo many men did not die to ineffective weapons . I did not base this mod on my personal opinion i did the research and did not use a surface-level effectiveness as a source of data .. For very ineffective weapon there was a good amount of subs lost just in 1939 to 1940 if consider the total number of subs sent to sea each month this is a rather high amount .

[CCIP]

Well, another factor to consider is accuracy. I think DC's in SHIII can be very, very accurate.

But, whatever the disagreements might be, there's one good thing: depth charge and weapon mods in general are very easy to implement over the top of any mod. So, you can definitely make it as a safe option for players.

I suggest, by the way, that you also give values like Depth Error a look. That's also in the depth charges file, and it seems to me like DC's are far too depth-accurate in the game by default.

As far as RUb - again, I think Beery's observations are generally based on long-term statistics of survivability. The settings might not be completely realistic per depth charge, but they've so far more or less proven themselves to result in very realistic survivability rates.

[Kpt. Lehmann]

Whatever you do Hopkins... Never stop looking at how to make things better. Keep doing what you are doing. Everyone has different preferences and the beauty of SH3 is its versatility.

This community is composed of many schools of thought and strong opinions are plentiful.

Don't get discouraged. :up:

[Der Teddy Bar]

hopkins32,
Historical evidence tends to suggest that your settings are overly ambitious.

There are many written examples where several depth charges in the ‘kill zone’ have caused only damage. Most U-boats sunk by depth charges were destroyed by damage accumulated from a long barrage rather than by a single carefully-aimed attack. Many survived hundreds of depth charge detonations over a period of many hours; 678 depth charges were dropped onto U-427 in April, 1945. The U-boat survived.

The experience of the standard depth charge initially used by aircraft completely refutes your proposal.

In the first two years of the war depth charges were mainly set for explosion at a depth of 30/45 metres [this figure having being set years ago and never altered since]. Analysis of pilot reports by ORS (Operational Research Section) showed that in 40% of attacks the U-boat was either still visible or had been submerged less than 15 seconds (these are the U-boats that we would expect to have most chance of killing as we have a good idea of their position). Since the lethal radius of a depth charge was around 5-6 metres it was clear that a shallower setting was necessary. Explosion at a depth of 15 metres was initiated and as new fuses became available at 10 metres and then 8 metres.

The above was normally in a group of 6 depth charges.

I quote from Naval Weapons...
In the first few months of the war only 5 percent of all depth charge attacks were successful. Normal combat conditions reduced that figure to 3 percent. Combat records showed that in early 1942 the lethal probability of a single depth charge pattern (barrage) was about 3 percent and five attacks would raise the chance of a kill to about 10 percent. The possibility of damaging a submarine was about 30 percent after five attacks.

By the end of 1943, better weapons and tactics had improved these figures such that about 30 percent of all detected submarines suffered at least some damage and 20 percent were killed. By the last year of the war, at least 35 percent of the submarines attacked were damaged while 30 percent were killed.

The British claimed this DC would split a 0.875 inch (22 mm) hull at 20 feet (6.1 m) and force a submarine to surface at about twice that distance. However, again, a lot of historical text proves that this was not a cut and dried situation, as again, where even in 1945 a u-boat survived 600+ depth charges.

As these aircraft attacks demonstrate, it was not easy to rupture the preassure hull of a u-boat.

U-128
Against U-128 74-P-6 dropped six Torpex-filled Mark 44 depth charges ahead of the swirl. All six were set at 25 feet. They exploded around the forward part of U-128. The pressure hull was ruptured near the forward starboard torpedo tubes, and water poured in through a four-finger wide gap and also through the forward galley hatch. The electric motors were put out of commission, as was the gyro compass.



U-1229
Shortly after noon on 20 August U-1229 was proceeding fully surfaced, as had been her recent custom, when an aircraft was sighted coming in for an attack some distance away. Fire was immediately opened on the plane which continued to come in at a low altitude and dropped its bombs close aboard the U-boat to port. The resulting explosions hurled five members of the gun’s crew, including the pharmacist’s mate, and one of the 20-mm. cannon overboard. The five men did not get back on board and were lost. The remainder of the bridge watch scrambled down the hatch as the U-boat crash-dived.

Within the boat there was little immediate damage noticeable although she was severely shaken up. Lighting came off the board, but was soon restored, and there was a small water entry through the conning tower hatch which was plugged without difficulty. The boat had plunged to 60 meters when it was realized that the batteries had been badly damaged. An estimated 35 cells had been cracked and the motors were losing power rapidly. The boat was then brought back up to 30 meters. In the meanwhile fear was expressed in the boat that one or more of the fuel tanks had been ruptured and that they were leaving an oil trace. (O.N.I. Note: This, in fact, was correct. Pilots were able to keep a constant watch on the U-boat’s position until she surfaced again largely due to the presence of a bubbling oil trace.)

The boat was now at 17 to 20 meters and it was decided to raise the Schnorchel and attempt to start the Diesels, although the top of the Schnorchel was still below the surface. The pressure on the exhaust proved too great, however, and the Diesels would not start. The two previous attempts having failed, tanks were now blown and the U-boat surfaced. As the periscopes and Schnorchel broached, a sharp rapping was heard in the boat which was accurately diagnosed as strafing from aircraft. The position of the boat was now considered hopeless and the order was given, now some two hours after the first attack, to abandon ship. AS the crew emerged from the conning tower they came under heavy strafing fire from the attacking aircraft and casualties were heavy. No attempt was made to man the guns. No attempt was made to scuttle as damage from strafing had already left the boat in sinking condition.

I hope that this helps :up:

[hopkins32]

Ahhh CCIP i can always count on you hehe , yes i have received 2 PM messages asking if this mod is done and complete and my reply to this is no there are many other aspects having to do with the DC's that i still need to edit , one of witch i know you are just going to hate LOL so ill be prepared for your next depth charge attack :-j oh and by the way please don't take me as if im mad or being sarcastic i just like to joke a bit and this is an argumentative topic . When the mod is complete and 100% you will see that it is a very accurate. The file that i have provided is enough to let people test the DC ranges for them selves to better get an understanding of what i am trying to do . I think Beery and the team are working in an a deferent direction than I and as you stated are generally based on long-term statistics of survivability. I am working the individual combat scenario where this risk is always there, a problem iv had with the game since it came out...

Der Teddy Bar i can provide many examples of DC attacks that are exactly the opposite lets take U-49 for example 5 DC's dropped set at various depths 150 to 350 feet. One charge exploded close to the conning tower and the boat began to flood. 1939 ... The fact is you can go all day at this there is tons of info that can confirm and dispute my current settings i dont think i need to make a page out of them ... what i am trying to do is find a good middle ground for SHIII .

I do enjoy your input thow so thanks guys.

[Beery]

Der Teddy Bar i can provide many examples of DC attacks that are exactly the opposite lets take U-49 for example 5 DC's dropped set at various depths 150 to 350 feet. One charge exploded close to the conning tower and the boat began to flood. 1939 ... The fact is you can go all day at this there is tons of info that can confirm and dispute my current settings i dont think i need to make a page out of them ... what i am trying to do is find a good middle ground for SHIII ..

Well a good middle ground should take the middle ground. It seems to me that you are heavily leaning towards one side, because there is a lot of info out there which suggests that, if you were using the standard depth charge that was in use in WW2, 5m was the maximum range at which fatal damage could occur.

Having said that, there's nothing to stop anyone releasing any mod, and there's nothing to stop people claiming their DC mod is ultra-realistic, even if it blows U-boats apart at a distance of 500 yards. Just be prepared for a bit of criticism if you err on the side of 'arcade'. :know:

[Twitch]

the way i see it..... yea, the DCs are a little underpowered as far as i can tell..

BUT

this is cancled out by the uber massive accuracy of the ships dropping them...

so the 2 kinda offset eachother..

[Pablo]

Hi!

IRL the fatal damage radius isn't fixed, but varies with the power of the depth charge explosion (more means a bigger radius) and the depth at which the explosion occurs (deeper means a smaller radius). Discussions of the physics involved may be found here (http://www.fas.org/man/dod-101/navy/docs/es310/uw_wpns/uw_wpns.htm) (and here (http://caltechbook.library.caltech.edu/22/01/chap6.htm) for the more mathematically inclined). I should think it extremely difficult for any mod using a fixed damage radius to be "realistic"; however, a fixed radius is all that SH3 has given us.

Given SH3's limitations, it seems to me that the physics are known and understood, so that it is likely the British were correct in claiming that a depth charge at a certain range would split metal of such-and-such a width at a specific depth (I'm guessing at or near the surface); a post-war U.S. Navy test sank a surfaced U-boat when a single depth charge was detonated 30 feet away (see this site (https://www.denix.osd.mil/denix/Public/ES-Programs/Conservation/Panther/panther2.html)).

If you assume that submarines are usually depth charged at greater depths, a "fatal radius" of from 4-7 meters is probably reasonable, but IMHO not going to affect the game very much given the difficulty in getting the depth charge to within a small fatal radius (be it 5 meters or 10 meters) - in game terms, dropping depth charge within a "game-ending" radius on the order of 15-30 feet when the submarine is moving both horizontally and vertically (see Teddy Bar's post regarding the analysis that went into setting depth charge depths for aircraft). Data at Navweaps.com (here (http://www.navweaps.com/Weapons/WAMBR_ASW.htm)) indicate that accuracy in depth charge placement was a significant factor, with relatively low effectiveness for depth charges fired from k-guns or rolled off the stern, but much greater effectiveness when depth charge settings were correlated with depth-finding sonar (such as with "Squid" launchers), or when knowing the U-boat's depth wasn't a significant factor (as with "Hedgehog").

The accuracy issue appears to be the problem in SH3: folks think the destroyers place depth charges much too accurately. For example, in SH3 surface ships lose contact with destroyers at a fixed radius, while IRL the distance varies with the depth of the submarine: a deep-diving submarine drops below the sonar beam further away from the destroyer, and thus can maneuver up, down, or away from the last sonar contact before the destroyer can move in and drop depth charges. No such luck in SH3 - a good destroyer crew can track you within (default) 200 yards of its position, regardless of depth, and then begin an attack run.

One complicating factor: IRL good destroyer teams would coordinate, with one destroyer maintaining lock-on with sonar and radioing position reports to the other ships which would close in for the kill. It's hard to tell how much of this information-sharing is either occuring (or is assumed to be occuring) with the ASW ships in the game.

Hope this helps!

Pablo

[hopkins32]

Ok after taking everyone's opinion and evidence into consideration this is what i have come up with at 5 to 7 meters the DC will cause fatal damage at 5 meters and can cause some flooding (mostly light for what iv seen in testing the files) at about 7 meters along with damage to internal and external equipment also at about 10 to 12 meters im getting some vary light damage... after this is complete then i can move on to the sonar since this is being made for 1.4b ..