[REL] Additional Depth Charges v1.0

[tomfon]

Description

SH3 and GWX feature only one type of depth charge. This simple mod introduces another four types of DCs for the American & British destroyers, destroyer escorts and frigates. The appearance of each type of depth charge depends on the type of each warship and of course on the progress of your career. This mod doesn't introduce a new 3D model either for the depth charge racks or for each type of depth charge barell. The core of the mod originates from the NYGM supermod which already includes a mod that adds additional types of depth charges to the game (New Depth Charge Racks & New Depth Charges Mod). 'Stiebler' granted me permission to use the mod and as a result i modified the relative files and also edited the .eqp files.

The mod introduces the following versions of depth charges:

---American DCs---

*Mark 6: The standard depth charge used by the U.S. Navy for most of the war. Its terminal velocity was 2.4 m/s (meters per second) or 8 f/s (feet per second).

*Mark 7 (Mod 1): This version was used early in the war and it had a terminal velocity of 2.7 m/s or 9 f/s.

*Mark 9: The standard version used by USN ships in the latter part of the war (1943 onwards). Despite the fact that it was lighter compared to Mark 6 & 7 types, it was more powerful because its explosive charge was Torpex instead of TNT. The terminal velocity of this depth charge was 6.9 m/s or 22.7 f/s.

---British DCs---

*Mark VII: The standard DC used by the Royal Navy for the first three years of the war. It was relatively faster compared to the American Mark 6 & 7, with a terminal velocity of 3.0 m/s or 9.9 f/s.

*Mark VII Heavy: This depth charge had an improved sinking rate of 5.1 m/s or 16.8 f/s due to a cast-iron weight attached to it.


Things that work (Technical info)

• Sink Rate/Terminal velocity. It works but there is a limitation. Read below.
  
  
• Depth precision. I left it unchanged (15 m). Depth charges will detonate randomly at this variance. Example: If the firing depth is set by the AI to 100 m, the depth charge will explode randomly between 85 and 115 m.
  
  
• Min and Max blast radius. Max radius: For the Mark 9 it is 25 m, for the Mark 7, 30 m and for all others it is 20 m. A single-hulled American WWI/WWII submarine would take minor to moderate damage if a DC charged with 300 pounds (~136 kg) of TNT exploded at a distance of 50 to 100 feet (ref. 1, §15-12). It is known that U-boats could do much better since they were double-hulled. So, with depth precision set at 15 m, if a Mark 6 DC detonates 15 m away from the U-boat's hull, the U-boat will suffer minor to moderate damage. Likewise, the U-boat will suffer almost no damage if the detonation occurs 20 m away. Min radius: I specified a value of 4.5 meters (ref. 5). This means that if your U-boat happens to be within a 4.5 m radius from the epicenter of the explosion then the full amount of points of damage will be applied.
  
  
• Shockwave effect. I made it weaker but has no effect on blast radius. It doesn't affect the performance of depth charges, in general.

Limitations

1. As soon as a depth charge enters water it immediately acquires its terminal velocity. This is not the real case.

2. Every depth charge had a maximum depth setting. In SH3 the maximum depth setting for all DCs is 300 m.


Compatibility & Installation

This mod is JSGME ready. It is compatible only with GWX 'Gold' v3.0. It is also compatible with:

*Longer Repair Times v2.04 (LRT v2.04).
*Every option of "OLC 'Gold' MkII".

Installation instructions are provided in the README file.


Thanks & Acknowledgements

1. 'Stiebler' for allowing me to use specific files (read above).
2. 'skwas' for his S3D utility.
3. 'padi' for his 'Real ASW Mod' from which i derived useful information regarding availability dates.


Interesting readings (References)

1.War Damage Report No.58 (US Hydrographic Office)
2.Depth Charges (The Pacific War Online Encyclopedia)
3.Mark 6 & Mark 7 Depth Charges
4.American & British ASW Weapons
5.Depth Charge (Wiki)


Further development

Though this mod includes most of the basic types of depth charges there are other types which i would like to add to the game. In addition, it would be nice if i could find the time to expand the mod in such a way that it depicts the correct amount of depth charges each type of destroyer & frigate carried. We'll see.

DOWNLOAD (SUBSIM)
DOWNLOAD (MEDIAFIRE)

[A6Intruder]

Hi,
could you please explain the differeces between your Mod and Real ASW Mod from Padi.
Thanks in forward.
Best regards

[tomfon]

Hello A6Intruder.

Well, my mod is compatible with GWX3. If you'd like to use padi's mod instead you should then edit all .eqp files so as to link the 3D model of each ship with the corresponding depth charge taking into account the type of the ship and the date.

There are some other differences regarding the properties of DCs (min & max efficiency radius,depth precision, hit points, shockwave effect).

What really troubled me was the efficiency radius and depth precision.

I will try and post my findings later.

[sublynx]

Very cool!

[Anvar1061]

Originally Posted by sublynx

Very cool!

Additional Depth Charges v1.0 (GWX3)

Real ASW Mod v.3 Beta 4

[tomfon]

@Anvar1061

In case you haven't read the description of the mod: It doesn't include new 3D models for the barrels.

So, please don't hijack the thread. If you don't like it, don't use it.

[Anvar1061]

Why do not you do better than v.2?

[rudewarrior]

I have been using Jungman's RealDC_4 mod to simulate changes in depth charges through the war. It very simply modifies the rate of descent and other features of the depth charges throughout the war to make it a little more challenging. I implement the changes through the war using SH3 Commander.

So the question I have is, would it be better to use this mod instead of RealDC_4? Also, I have some pretty good experience modding, so making the two mods compatible with my mod soup would take some work, so I am trying to figure out if it would be worth the time to make them compatible with each other and then my mod soup, etc. I think someone who is more familiar with the inner workings could give me a quick answer and I can dig into it more from there.

I can't find the link to Jungman's mod, but I have included the read me, so it might help answer questions about it.

RealDC_4 Mod   version 4.0  May 16, 2005   Jungman

This is a simple mod made for Silent Hunter III that changes 
the DepthCharge.zon and DepthCharge.sim files to simulate a more realistic DC model 
over the several years. From early to late war average values.

It was made for patch 1.3 but will work on all versions prior since 
this original file is not changed by any previous patches.

Please backup your original file!

Place the two files directory data/library replacing the original Depthcharge.zon and
DepthCharge.sim file.

"The two changes that are made is Maximum Range reduced from 40 meter to 10 meter,
and the Sinkng Speed increased from 3 m/s to 4.5 m/s war average."

Update for 4.0 depth precision put back to default 5 meters. I do not see that it has
much effect. Maximum blast radius reduced to 10 meters.


So Uboat should not be hurt at all if DC explosion is more than 10 meters away, but harder
to avoid the DC at depth below 50 meters to simulate the improved technology of later years. 
Sinking speed 3 m/s to 6 m/s at war end. I feel 4.5 m/s is good average. 

If you want only the reduced Maximum Blast Radius only (with default 3 m/s sink speed),
then only install the DepthCharge.zon file only.

The DepthCharge.sim will increase sink speed to 'Middle War' value of 4.5 m/s 
making them more chance to hit you at depth.

----------------------------------------------------------------------------
Change Log:
 
1) DepthCharge.zon 

The Mininum Range is still at default 4.5 meter.

The MinEF is still default 170 and MaxEF is still at default 230. (Strength of explosion).

The Maximum Range was reduced from default 40 meter to 10 meter. (version 4.0 change).

---------------------------------------------------------------------------
2) DepthCharge.sim

Sink rate increased from default 3 m/s to 4.5 m/s. (Early and Late War average. Version 4.0)

Depth Precision is back to default 5 meters. (version 4.0)
_________________________________________________________________________________________

Later updates will be done considering feedback.
 
I can change Strength, Sink speed, Precision (does not seem to do anything)
and Blast radius.

Happy Hunting!

[ivanov.ruslan]

Congratulations on the work of Tomfon!


Here is DC4 http://www.subsim.com/radioroom/down...o=file&id=3174

[tomfon]

@rudewarrior

Additional DCs includes a modified depthcharges.dat which has extra nodes added. Each of the extra node (as well as the original one) corresponds to a specific type of DC. The technical parameters of each DC can be found in the .sim and .zon files. So, basically, the mod adds new DCs to the game which will show up according to date and, of course, type of warship. Now every DC has its own specific attributes (terminal velocity, hit points etc.). This is the main difference between Real_DC and this mod. Therefore, i don't see any reason why merge these two mods. Instead, you could modify any of the values according to your taste.

@ivanov.rusian

Thanks!

[geosub1978]

The main problem with the DCs in the game is that they are set to explode at your depth which is not realistic, because it was (and still is more or less) impossible to determine the depth of the submarine. That's why they were set to explode with a depth pattern, unless it was known that the submarine was the previous moments at periscope depth and were set to shallow depth.

[rudewarrior]

Originally Posted by tomfon

So, basically, i don't see any reason why to merge the two mods. Instead, you could modify any of the values to your taste.

Thank you sir! You have confirmed exactly what I suspected! Additional Depth Charges it is!

Great work!

[Pablo]

Originally Posted by geosub1978

The main problem with the DCs in the game is that they are set to explode at your depth which is not realistic, because it was (and still is more or less) impossible to determine the depth of the submarine. That's why they were set to explode with a depth pattern, unless it was known that the submarine was the previous moments at periscope depth and were set to shallow depth.

Hi!

I'm guessing that the time required to develop algorithms, as well as the CPU time required to give AI ships the ability to use realistic depth patterns in a real-time simulation was probably more than the computers of 10 years ago could handle.

Pablo

[pathealey2]

Excellent work. Thank you - trying it now.

[tomfon]

Originally Posted by geosub1978

The main problem with the DCs in the game is that they are set to explode at your depth which is not realistic, because it was (and still is more or less) impossible to determine the depth of the submarine.

I wouldn't know about the efficiency of contemporary sonars and underwater detection systems, though it is quite interesting from a certain perspective.

Now, regarding the behavior of depth charges in SH3: Depth charges do detonate randomly at a given variance. There is a special entry for this in the .sim file called, "depth_precision". So, if you set a value of 5m then, if the AI sets the firing depth, say at 100m, the depth charge will detonate randomly between 95 and 105m.

In my opinion, the main problem with depth charges in SH3 is that the damage inflicted to the U-Boat from a certain type of DC depends exclusively on the distance of the U-boat from the epicenter of the explosion. For a proper simulation to take place other important factors should be taken into account too, such as the relative points of detonation, the fact that the damage is expected to be more effective when the detonation occurs under the hull (see reference 1, §15-10) and, of course, hydrostatic pressure.

Depth charges in SH3 (and why not, in SH4 too) don't/won't work the best way possible. But we do what we can.

Obviously, i'm asking for too much.