Prototype 15cm 9-tube ASW Rocket Launcher

[Edit] Prototype 15cm 9-tube ASW Rocket Launcher No.288 試製15cm9連装対潜噴進砲
Depth Charge Effects: +15 +1 Scrap value: 9 3 2 (Unbuildable)
Refittable Ship Types
Coastal Defense Ship	Destroyer
Light Cruiser	Torpedo Cruiser
Heavy Cruiser	Training Cruiser
Aviation Cruiser	Fast Battleship
Battleship	Aviation Battleship
Light Carrier	Standard Aircraft Carrier
Armored Carrier	Seaplane Tender
Submarine	Aircraft Carrying Submarine
Submarine Tender	Fleet Oiler
Repair Ship	Amphibious Assault Ship

Introduction

爆雷投下軌条は艦の後方、従来型の三式爆雷投射機は艦の舷側方向に爆雷を投射可能でしたが、艦首方向にも爆雷を投射可能な新対潜装備が本噴進爆雷砲です。
まだ、試作段階で欧米の同種兵装に比べて発展途上ではありますが、和製ヘッジホッグに発展する可能性もあった兵装です。

Depth charge launchers on ships' sterns and existing Type 3 depth charge projectors could throw depth charges to the sides of a ship, but this rocket launcher could throw depth charges ahead of the ship's bow as well.
This system was still a mere prototype in comparison to Western developments of similar weaponry, but it had the potential to become something akin to a Japanese-made Hedgehog.

Mechanics

Depth Charges are one of the main equipment used for ASW, greatly enhancing ASW Damage Synergy. Their main stat is "ASW" .

ASW Damage Synergy
Small Small Sonars	Type 93 Passive Sonar Type 4 Passive Sonar Type 3 Active Sonar Type 3 Active Sonar Kai Type124 ASDIC Type144/147 ASDIC HF/DF + Type144/147 ASDIC
Large Large Sonars	Type 0 Passive Sonar
DCP Depth Charge Projectors (DCP)	Type 94 Depth Charge Projector Type 3 Depth Charge Projector Type 3 Depth Charge Projector (Concentrated Deployment) Prototype 15cm 9-tube ASW Rocket Launcher RUR-4A Weapon Alpha Kai AP Mk.32 ASW Torpedo (Mk.2 Thrower) AP
DCR Depth Charge (Racks) (DCR)	Type 95 Depth Charge AP Type 2 Depth Charge AP Lightweight ASW Torpedo (Initial Test Model) AP Hedgehog (Initial Model) AP Type 2 Depth Charge Kai Ni AP
Other ASW Mortars	Type 2 12cm Mortar Kai Type 2 12cm Mortar Kai (Concentrated Deployment)
ASW Damage Modifiers: [math]\displaystyle{ \text{Mod}_\text{synergy} = {Mod}_\text{1} \times {Mod}_\text{2} }[/math]
[math]\displaystyle{ {Mod}_\text{1} }[/math]	+ (Any Sonar + Any Depth Charge)	1.15
[math]\displaystyle{ {Mod}_\text{2} }[/math]	DCP + DCR and NO Small	1.1
	Small + DCP + DCR	1.25
Examples
[math]\displaystyle{ \text{Mod}_\text{synergy} }[/math]	Small + DCP + DCR	1.4375[math]\displaystyle{ 1.15 \times 1.25 }[/math]
	Large + DCP + DCR	1.265[math]\displaystyle{ 1.15 \times 1.1 }[/math]
Armor Penetration
Indepentant of synergies, some equipment provides additional armor penetration to ASW attacks. The affected equipment are: DCR: Type 95 DC, Type 2 DC, Lightweight ASW Torpedo, Hedgehog, Type 2 DC K2 DCP: RUR-4A Weapon Alpha Kai, Mk.32 ASW Torpedo (Mk.2 Thrower). The flat armor penetration value is calculated as follows: [math]\displaystyle{ \text{Pen} = \sum\limits_{\text{Equipment}} \Big( \sqrt{\text{ASW}_\text{Equipment} - 2} + \text{Mod}_\text{ship} \Big) }[/math] With [math]\displaystyle{ \text{ASW}_\text{Equipment} }[/math] the base ASW stat of the applicable equipment, Visible Bonuses and Improvements are not counted here. [math]\displaystyle{ \text{Mod}_\text{ship} }[/math] being 1 for DE, 0 otherwise, Note Armor penetration from equipment stacks, The final armor of the targetted submarine cannot go below 1.

Notes

How To Obtain

From limited-time quest: Su09, 2401 B3 (x2, choice)

Ranking reward for:

• Nov 2021: 1-5 (★+5), 6-20 (★+4), 21-100 (★+3), 101-500 (★+2)

Event reward for:

• Summer 2020 Event E-1: Hard
• Fall 2021 Event E-2: Hard (★+2)
• Summer 2023 Event E-1: Hard (★+2, choice), Medium (choice)

Updates History

• 2018-05-15: Implemented
• 2020-01-14: Visible bonuses added

Fit Bonuses

Ship	Extra Requirement								Note
Isuzu Kai Ni Naka Kai Ni Yura Kai Ni Yukikaze Kai Ni					+2			+1
Yuubari Kai Ni D		+1			+3			+2
Noshiro Kai Ni					+4			+1
Katori-class					+3			+2	Added 2021-03-01

Improvement

Improvement effects
	1★	2★	3★	4★	5★	6★	7★	8★	9★	Max★
	0.75	1.06	1.29	1.50	1.67	1.83	1.98	2.12	2.25	2.37
	0.67	0.94	1.15	1.33	1.49	1.63	1.76	1.89	2.00	2.11