[TEC] Depth Charge mod

[doomlordis]

Ok i have spent hours testing the effectiveness of depth charges and they are flawed.

They have to explode within around 2 meters from the hull to do any damage and they only ever damage systems and cause very minor flooding , hull damage never changes.

I modded them using goblin , the normal damage is 50 - 100 , i made them 600 - 600 and no real improvement.

I also changed the AP up to 40 from 20 with no change.

(i patrolled off portsmouth to test this , 5 destroyers attacked )

I think there must be another value maybe to do with the sub that is causing this, anyway i am no expert and would love some help.

If we dont fix this the game is pointless.

[ERPP8]

Ok i have spent hours testing the effectiveness of depth charges and they are flawed.

They have to explode within around 2 meters from the hull to do any damage and they only ever damage systems and cause very minor flooding , hull damage never changes.

I modded them using goblin , the normal damage is 50 - 100 , i made them 600 - 600 and no real improvement.

I also changed the AP up to 40 from 20 with no change.

(i patrolled off portsmouth to test this , 5 destroyers attacked )

I think there must be another value maybe to do with the sub that is causing this, anyway i am no expert and would love some help.

If we dont fix this the game is pointless.
Don't forget the.sim file!

[Heretic]

see this:
http://www.subsim.com/radioroom/showpost.php?p=1352492&postcount=81

[doomlordis]

I opened the gr2 then merged the zon and sim , is that correct?

[wamphyri]

What you want to look at isn't so much the damage amount or AP .. those are good as default. It's the min/max radius that you want to look at. These settings decide how much damage is capable of being done from the initial explosion point.

An example :

In sh5 stock : min max of standard dc barrel = 2m and 4m

In GWX sh3 : min max of standard dc barrel = 4.5m and 40m

So change the damage back to normal and try the different min/max radius .. you'll be happy with the result .. unless you die :)

[doomlordis]

Thanks, will give this mod a try !

[doomlordis]

set mine to 4 - 40 and it is much better, hull damage and flooding now more realistic , thanks!

[keith_uk]

I received 11% hull damage from depth charges two days ago.

Keith.

[Ducimus]

Items i can clarify that might not be apparent:

detonate_depth
has never really worked for DC's in Sh3/4. Works with hedgehogs though.

depth_precision
How accurate the DC is, plus or minus it's intended depth. If the AI sets the DC to explode at 100 meters, with a depth percision of 5 it will explode randomly between 95 meters and 105 meters.

explosion_range
How far you can feel the the explosion. The higher you set this the more you'll feel the DC and rock underwater. Set it REALLY high and DC's will propel your boat underwater at unrealistic speeds, and bounce it up and down in depth.


MinEF
MaxEF
Damage varience. Will do X much at a min, but has chance to do Y much at max. Damage done by each DC is randomized based on these numbers. The closer you set these, the more consistant the damage will be.

MinRadius
MaxRadius

Similar to the damage varience, only it effects damage area. If you have a min radius of 4.5 and a max of 40, then from 0 to 4.5 meters, the FULL amount of damage that DC does (see damage varience) is applied. From 4.6 meters to 40 meters, damage is applied by diminishing returns. The closer you are to the center of the explosion at 4.6 meters, the more damage it does, with being farther way at 39-40 meters doing the least amount of damage.

[Mraah]

Here are some web links about the standerd DC and the Mark 9 ... basic geez wiz facts but note the lb's of explosive, and pistol's min depth (around 45 feet) ... the mark 7 had 290-300 lbs whilst the mark 9 had 200 lbs.

Mark 6-7 ... http://www.hnsa.org/doc/depthcharge6/index.htm

Mark 9 .... http://www.hnsa.org/doc/depthcharge9/index.htm

Now, here's an interesting link talking about damage radius and the underwater explosion ... Note the small radius' ...

http://www.absoluteastronomy.com/topics/Depth_charge

Quote from above link ...
The Mark VII's 290 pound (132 kg) Amatol. Amatol is a highly explosive material made from a mixture of TNT and ammonium nitrate. Amatol was used extensively during World War I and World War II... charge was estimated capable of splitting a 7/8-inch (22 mm) submarine pressure hull at a distance of 20 feet (6.1 m), and forcing the submarine to surface at twice that distance. Change of explosive to Torpex (or Minol) at the end of 1942 was estimated to increase those distances to 26 feet (7.9 m) and 52 feet (15.8 m).

Also, at that link, goto the bottom under the title "Underwater explosions". The damage that an underwater explosion inflicts on a submarine comes from a primary and a secondary shockwave. The primary shockwave is the initial shockwave from the depth charge, and will cause damage to personnel and equipment inside the submarine if detonated close enough. The secondary shockwave is a result from the cyclical expansion and contraction of the gas bubble and will bend the submarine back and forth and cause catastrophic hull breach, in a way that can be best described as bending a plastic ruler back and forth until it snaps. Up to sixteen cycles of the secondary shockwave has been recorded in tests. The effect of the secondary shockwave can be reinforced if another depth charge detonates on the other side of the hull in a close proximity in time of the first detonation, which is why depth charges normally are launched in pairs with different pre-set detonation depths.

The killing radius of a depth charge depends on the payload of the depth charge and the size and strength of the submarine hull. A depth charge of approximately 100 kg of TNT would normally have a killing radius (hull breach) of only 3-4 meters 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. A higher payload only increases the radius by a few meters due to the fact that the effect of an underwater explosion decreases with the distance cubed. The killing range would be greater against a larger submarine and shorter against a smaller submarine. It is doubtful if the hull of a midget submarine with a titanium hull could be sunk by a depth charge by anything less than a direct hit, even though it could be decommissioned with less.


Ducimus? I feel that (looking at the data, in theory) that the detonation_depth and depth_precision are tied together, where the hedge hog has a value of 0 at 2500 meaning it requires a contact detonation up to 2500 meter's (depth) and the DC with 5 at 25 meaning that between 0-25 meters (depth) the DC will detonation within 5 meters of the sub's hull. If those conditions aren't met then it uses the depth setting the escort set .... purely speculation and I know you've done the tests in SH3/4 ... any thoughts?

EDIT NOTE : My other direct comparision thought between the two values goes back to your finding, but it could be a linear relationship. ie, precision=5, detonation=25 meaning that for every 25 meters (depth) it will vary by 5 meters ... so at 50m depth, the variance would be (+/- 10), at 75m (+/- 15), 100m (+/- 20), etc.

Thanks,

Rob

P.S. I'm waiting for the Mark X "One Ton" charge to be modded into the game, although barely seen in SH5 campaign, perhaps sparingly in the Black May camp.

[Ducimus]

I feel that (looking at the data, in theory) that the detonation_depth and depth_precision are tied together, where the hedge hog has a value of 0 at 2500 meaning it requires a contact detonation up to 2500 meter's (depth) and the DC with 5 at 25 meaning that between 0-25 meters (depth) the DC will detonation within 5 meters of the sub's hull. If those conditions aren't met then it uses the depth setting the escort set

Thats a good theory, and worth an experiment, but i'll tell you why i think it behaves the way i think it does.

When i played SH3, i made myself a little cheat, cause i was tired of being killed by hedge hogs. I plugged in a detonation depth of.. ehhh.. i think it was 200 meters. I then gave it a depth precision of 20. What would happen, is if the hedge hog projectile didn't contact me (and thereby explode), it would then behave as a mini depth charge. So imagine that huge circle of hedge hogs, each exploding anywhere between 180 and 220 meters. It made ALOT of noise. If i set the depth precision to 0, it would detonate at 200 meters.

You can't do the same with depth precision with depth charges. It's long been a goal to make depth charges explode at a historically accurate depth, but the games AI settings, always seemingly overwrite whats in the file, and yet, i have always found it hard to completely believe that depth precision does absolutely nothing, but i've never noticed it having any discernible effect. Maybe it takes someone whos head is not "in the box" to figure it out?

[ddrgn]

I have been working on what I call the Feared Hunters mod, getting great results so far, I will post a video in the next few days showing me taking on an elite dd and losing badly trying to avoid him, and a mod to follow of course.

I am tinkering with the barrels .sim, and .zon only.

[Mraah]

You can't do the same with depth precision with depth charges. It's long been a goal to make depth charges explode at a historically accurate depth, but the games AI settings, always seemingly overwrite whats in the file, and yet, i have always found it hard to completely believe that depth precision does absolutely nothing, but i've never noticed it having any discernible effect. Maybe it takes someone whos head is not "in the box" to figure it out?

Ducimus,

I had another theory posted in EDIT ... any thoughts on that or does it go back to what you said above? Thanks for your work, it's always been appreciated!

EDIT NOTE : My other direct comparision thought between the two values goes back to your finding, but it could be a linear relationship. ie, precision=5, detonation=25 meaning that for every 25 meters (depth) it will vary by 5 meters ... so at 50m depth, the variance would be (+/- 10), at 75m (+/- 15), 100m (+/- 20), etc.

[rascal101]

Lord I hope you get somewhere with this - the escort AI is improved with various mods that are already released but its all rendered a bit useless if you go to max dept and silent running - the escorts might as well turn a hose on you for all its worth

Iproving the affectivness of the actual depth charges as they are dropped will be a great thing, also wondering if you can adjust the depth that the charges explode - sure early in the war the allies we'nt quite aware how deep the Uboats could go - but this was fixed and I'd like to see this improvement modeled in the game otherwise it will become increasingly less of a challenge

Thanks again for your work

Regards
Rascal

[tater]

Assuming this is unchanged from SH4 (I did a LOT of work on SH4 DCs), detonate_depth does nothing for ship-launched DCs (except HHs).

Air-dropped DCs use this functionality.

The AI overrides this value, and sets the charge where it thinks you are. This was important for the PTO because IJN DCs only had 2 depth settings until 1943, when they got a 3d—all of which were too shallow.

In addition, the depth precision is the range at which they explode, but really they need a fuse precision as well. If the DC could only be set in 5 meter "ticks" then they'd have to decide to drop some at one depth, some at another. Then some randomness on top of that.

Also, you need to be careful about the radius because if the sub is shallow, there is no MINIMUM setting for depth, so you're at PD, and the escorts drop DCs that instantly go off, and wreck the escort (sinking it sometimes, but often blowing up the DC launchers).

DC thread
http://www.subsim.com/radioroom/showthread.php?t=123307