Improving Ship Speed

Introduction

By equipping a Turbine and an Engine it's possible to make fast destroyers like Shimakaze go speeds far beyond fast. As shown here, using a Improved Steam Turbine and a New High Pressure-Temperature Steam Boiler will result in Shimakaze going to Fastest

Speed represents the speed of a ship girl. Ship girls are either slow (低速) or fast (高速) by default. As of the 10 Jan 2017 Update, ship girl speed can be further increased to fast+ (高速+) or fastest (最速) by using a combination of Turbine with one or more Boilers
.

Overview

By equipping a Turbine and an Engine it's possible to make Battleship like Yamato go from slow to fast. As shown here, using a Improved Steam Turbine (shown in the expansion slot) and an Enhanced Steam Boiler will result in Yamato going to Fast allowing her access to path branching she would otherwise not have access to when she was Slow.

There are several effects of increasing ship girl speed:

• Meeting routing requirements.
  • Slow ships can be sped up to fulfil certain branching requirements.
    • Note that this does not apply to ship type requirements. Eg a BB will not count as a FBB where FBBs are specifically required.
  • Fast+ and fastest are required to fulfil routing requirements in some maps. Eg. 3-2 and 4-5.
• Combined Fleet composition.
  • Slow battleships that are fast+ can be placed in the escort fleet.
• Evasion increase.
  • Although this has been stated by the developers to occur, testing has not shown any significant increase in evasion.
• Because Coastal Defense Ships cannot equip , they are the only ship type that cannot be sped up.

Speed Change Charts

It is highly recommended that you have a Reinforcement Expansion on ship girls that you wish to speed up. It can severely degrade their combat efficiency if you attempt to speed up ship girls without one.

• Enhanced Kanhon Type Boiler = +10 Boiler
• New Model High Temperature High Pressure Boiler = +13 Boiler

All synergies listed below already include 1 Improved Kanhon Type Turbine because it is an absolute requirement for speed ups.

Speed Groups
Base Speed	Speed Group	Type	Exceptions
Fast	A	CAV	CV(B/L): Shoukaku-class, Taihou, Mogami-class Kou Kai Ni CA: Mogami-class, Tone-class DD: Amatsukaze Kai Ni, Shimakaze, Tashkent AV: Mikuma Kai Ni Toku
	B1	N/A	FBB: Kongou-class, Yamato Kai Ni, Iowa-class CV: Souryuu, Hiryuu, Unryuu, Amagi CL: Agano-class DD: Amatsukaze/Kai
	B2	FBB, CV, CVB, CA, CL, CLT, DD	CVL: Ryuujou, Ryuuhou Kai Ni, Shouhou-class, Chitose-class Kou, Independence-class
	C	AV	CV: Kaga CL: Yuubari/Kai DD: Samuel B. Roberts Mk.II
Slow	A	N/A	BB(V): Yamato-class, Nagato-class Kai Ni CVL: Houshou Kai Ni/Sen
	B	BB, BBV, CVL, CT, AS, AO, LHA	FBB: Gangut CL: Yuubari Kai Ni Toku DD: Samuel B. Roberts/Kai AV: Mizuho, Akitsushima, Commandant Teste, Kamoi Kai AR: Asahi Kai
	C	SS, SSV, AR	AO: Hayasui LHA: Akitsu Maru
	None	DE	N/A

Speed exceptions
Ships	Speed group	Exception	Notes
All Fast A		+1 Fit Bonus with the +13 Boiler at 7+	Stackable
All Slow A		+1 Fit Bonus with the +13 Boiler at 7+ & a Turbine
Houshou Kai Ni/Sen	Slow A	+1 Fit Bonus with the +13 Boiler	Not self-stackable Stackable with above only for +13 Boiler at 6-
Sentaka Type	Slow C		Not self-stackable
Yuubari Kai Ni Toku Samuel B. Roberts/Kai	Slow B	Speed set to Fast when equipping a Turbine	Not self-stackable Bonus disabled if equipping any "other" variants of Engine Improvement . Regular speed modding behaviors then.
Amatsukaze Kai/Ni Shimakaze Kai	Fast A/B1	Can equip Boilers in the RE

Simplified Engine Synergies
Speed Increments	Boiler Type	Boilers Required
		Fast A	Fast B1 Slow A	Fast B2 Slow B	Fast C Slow C
+1	Any boiler	1
+2	+13 boilers	1	2	2	N/A
	+13 boiler + +10 boiler = Total	0+ 0+ 2	1+ 0+ 2	0+ 0+ 2
+3 (Slow A only)	+13 boiler + +10 boiler = Total	N/A	1+ 0+ 3	N/A

Engine Synergies
Engine Improvements							Speed groups
							Fast				Slow
							A	B1	B2	C	A		B		C
Main Slots Required		Turbine	+10 Boiler	+13 Boiler	+13 Boiler 7+						Houshou K2/Sen	A	Yuub K2T SamyB/K	B	Sentaka Type	C
0	0	0	0		fast				slow
0	1	0	0		fast				slow		fast	slow
1+	0	1+	0		fast				slow
1+	0	0	1+	0	fast				fast	slow			fast	slow
1	0	0	0	1	fast +	fast
2+	0	0	0	2+	fast ++
1	1	1	0		fast +	fast +	fast +	fast +	fast		fast		fast
2	1	2	0		fast ++
3+	1	3+	0				fast ++				fast +
1	1	0	1	0	fast ++	fast +	fast +		fast +	fast	fast		fast +	fast
2	1	0	2	0		fast ++	fast ++		fast ++	fast +	fast +
3+	1	0	3+							fast ++
2	1	1	1			fast ++	fast +		fast ++	fast +	fast
3+	1	2+	1+			fast ++	fast ++		fast ++		fast +
3+	1	1+	2+			fast ++	fast ++		fast ++		fast +
1	1	0	0	1	fast ++	fast +	fast +	fast +	fast +		fast		fast +	fast
2+	1	0	0	2+		fast ++	fast ++		fast ++		fast +
2	1	0	1	1		fast ++	fast ++		fast ++	fast +	fast +