[REL] Additional Depth Charges v1.0

[tomfon]

Description

This simple mod introduces four additional types of depth charges for American and British destroyers, destroyer escorts, and frigates.
The type of depth charge deployed depends on the class of warship and, of course, on the progress of your career.

This mod does not introduce new 3D models for either the depth charge racks or the individual depth charge barrels.

The core of the mod originates from the NYGM supermod, which already includes an expansion that adds new types
of depth charges (the New Depth Charge Racks & New Depth Charges Mod). Permission to use this mod was kindly granted by Stiebler.
Based on that, I modified the relevant files and edited the .eqp files accordingly.

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 had a terminal velocity of 2.4 m/s (meters per second),
or approximately 8 ft/s (feet per second).

*Mark 7 (Mod 1): This version was used early in the war and had a terminal velocity of 2.7 m/s (meters per second),
or approximately 9 ft/s (feet per second).

*Mark 9: The standard version used by U.S. Navy ships in the latter part of the war (from 1943 onward). Although it was lighter than the Mark 6 and Mark 7 types,
it was more powerful due to its explosive charge being Torpex instead of TNT. Its terminal velocity was 6.9 m/s (meters per second),
or approximately 22.7 ft/s (feet per second).

---British DCs---

*Mark VII: The standard depth charge used by the Royal Navy during the first three years of the war. It was relatively faster than the American Mark 6 and Mark 7,
with a terminal velocity of 3.0 m/s (meters per second), or approximately 9.9 ft/s (feet per second).

*Mark VII Heavy: This depth charge featured an improved sinking rate of 5.1 m/s (meters per second),
or approximately 16.8 ft/s (feet per second), thanks to a cast-iron weight attached to it.


Things that work (Technical info)

• Sink Rate/Terminal velocity. It works, however, there is a limitation. Read below.
  
  
• Depth precision. I left the depth variance unchanged at 15 meters. Depth charges will detonate randomly within this range.
  For example, if the AI sets the firing depth to 100 meters, the depth charge will explode at a random depth between 85 and 115 meters.
  
  
• Min and Max blast radius.
  
  Max radius:
  
  For the Mark 9, the depth variance is set to 25 meters; for the Mark 7, it is set to 30 meters; and for all other types, it is set to 20 meters.
  
  A single-hulled American WWI/WWII submarine would sustain minor to moderate damage if a
  depth charge containing 300 pounds (~136 kg) of TNT detonated at a distance of 50 to 100 feet
  (see ref. 1, §15-12). U-boats, being double-hulled, were known to withstand such blasts more
  effectively.
  
  With the depth precision set to 15 meters, a Mark 6 depth charge detonating 15 meters from a
  U-boat's hull would result in minor to moderate damage. If the detonation occurs 20 meters
  away, the U-boat would likely suffer little to no damage.
  
  Min radius:
  
  I specified a value of 4.5 meters (see ref. 5). This means that if your U-boat is
  within a 4.5-meter radius of the explosion's epicenter, the full amount of damage points
  will be applied.
  
  
• Shockwave effect. I reduced its strength, but this has no effect on the blast radius. Overall, it doesn't impact the performance of depth charges.

Limitations

1. As soon as a depth charge enters the water, it immediately reaches its terminal velocity. However, this is not realistic.

2. In reality, each depth charge had a maximum depth setting. In SH3, however, the maximum depth setting for all depth charges is set to 300 meters.
This means that all depth charges will detonate once they reach that depth, unless they have already exploded. Therefore, if you want to increase your
chances of surviving the war, it would be a nice idea to acquire a VIIC/41 U-boat, as soon as the type becomes available...


Compatibility & Installation

This mod is JSGME ready. It is compatible 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 can be found 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 the 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

Although this mod includes most of the basic types of depth charges, there are other types I would like to add to the game.
Additionally, it would be great if I could find the time to expand the mod to accurately depict the number of depth charges carried by each type of destroyer and frigate. 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.

[pathealey2]

Excellent work. Thank you - trying it now.

[tomfon]

Originally Posted by pathealey2

Excellent work. Thank you - trying it now.

Hello, pathealey2 and welcome onboard!

[geosub1978]

If this is for any help:

I had once met a wolfpack outside Portugal. I fired a stern tube at one of the submarines just to see what would happen...the torpedo hit the submerged submarine at the rear...however, the only apparent effect was a paint scratch...

[rudewarrior]

Two questions:

1. Is what you define as "shockwave effect" the same as explosion_impulse?
2. What exactly is explosion_impulse? Perhaps the time length of the explosion in ms?

Thanx for the info.

[tomfon]

@rudewarior

1. Exactly.
2. It defines the change of momentum due to a nearby explosion. If you specify a large number the boat will be "dragged" through the water... This parameter has no effect on the performance of depth charges and it is not related to the damage inflicted on the U-boat. So, yeah, it's the shockwave effect.

[Izgud]

Great mod! Exactly what GWX needs.