Improving Ship Speed

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

By equipping a Turbine and a Boiler it's possible to make a Battleship like Yamato go from slow to fast. As shown here, using a Improved Kanhon Type Turbine (shown in the expansion slot) and an Enhanced Kanhon Type 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.

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

Overview

There are several effects of increasing ship speed:

• Meeting routing requirements:
  • Fleet speed affect certain map routing.
    • Note that this does not apply to ship type requirements (eg. a BB will not count as an FBB where FBBs are specifically required).
    • Most map routings are only affected by slow/fast fleets, fast+ and fastest being required for routing in very few maps (eg. 3-2 and 4-5).
• Combined Fleet composition:
  • BB/BBV that are fast+ can be placed in the escort fleet of STF/TCF (only fast for Warspite Kai).
• 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 (DE) cannot equip Engine Improvements, they are the only ship type that cannot be sped up.

Speed Change Charts

It is highly recommended to have a Reinforcement Expansion on ships that are sped up. Ships sped up without using a RE will have severely degraded combat efficiency.

So far, only 2 types of "boiler" exist in the game, and they are referred to as:

• 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.

• Devs claim that higher speed values increase evasion. However, its magnitude/scope/existence is still investigated by players (preliminary tests suggest that there is no significant increase in evasion).

Speed and engine synergy
+13 boilers	+10 boilers	Group/Speed							Equipment evasion	Slots required
		Fast				Slow
		A	B1	B2	C	A	B	C
0	1	Fast+	Fast+	Fast+	Fast+	Fast	Fast	Fast	16	2
0	2	Fastest	Fast+	Fast+	Fast+	Fast	Fast	Fast	26	3
0	3+	Fastest	Fast+	Fastest	Fast+	Fast	Fast+	Fast	36+	4+
1	0	Fastest	Fast+	Fast+	Fast+	Fast	Fast	Fast	19	2
1	1	Fastest	Fastest	Fast+	Fast+	Fast+	Fast	Fast	29	3
2	0	Fastest	Fastest	Fastest	Fast+	Fast+	Fast+	Fast	32	3
1	2+	Fastest	Fastest	Fastest	Fast+	Fastest	Fast+	Fast	39+	4+
2	1+	Fastest	Fastest	Fastest	Fast+	Fastest	Fast+	Fast	42+	4+
3+	0+	Fastest	Fastest	Fastest	Fast+	Fastest	Fast+	Fast	45+	4+

Simplified table
Speed Increment	Required Boiler		Fast A	Fast B1 Slow A	Fast B2 Slow B	Fast C Slow C
+1	Any boiler		1
+2	Either	+13 boilers	1	2	2	N/A
	Or	+13 boilers, and	0	1	0
		Total boiler count	2	2	3
+3 (initially-slow ships only)	Either	+13 boilers	N/A	3	N/A
	Or	+13 boilers, and		1
		Total boiler count		3

Speed groups
Initial speed	Group	Ships, classes, types
		Destroyers	Light Cruisers	Heavy Cruisers	Battleships	Carriers	Others
Fast	A	Shimakaze · Tashkent		Tone-class  · Mogami-class		Taihou · Shoukaku-class  · Mogami-class CVL
	B1	Amatsukaze	Agano-class		Kongou-class  · Iowa · Yamato Kai Ni	Souryuu · Hiryuu · Unryuu · Amagi
	B2	Other DD	Other CL · CLT  · Yuubari Kai Ni/D	Other CA	Other FBB	Fast CVL · Other CV
	C	Samuel B. Roberts Mk.II	Yuubari			Kaga	Fast AV
Slow	A				Yamato-class  · Nagato-class Kai Ni	Houshou Kai Ni/Sen
	B	Samuel B. Roberts	Yuubari Kai Ni Toku		Other BB · BBV · Gangut	Slow CVL	Slow AV  · AS  · CT  · Other AO (all forms)  · Shinshuu Maru
	C						SS · SSV · AR · Hayasui · Akitsu Maru

Speed exceptions
Ships	Speed group	Exception	Notes
I-201-class	Slow C	+1 fit bonus with the New Model High Temperature High Pressure Boiler	Not self-stackable
Houshou Kai Ni/Sen	Slow A
Yuubari Kai Ni Toku Samuel B. Roberts/Kai	Slow B	Speed set to Fast when equipping a Improved Kanhon Type Turbine	Not self-stackable Bonus disabled if equipping any "other" variants of Engine Improvement . Regular speed modding behaviors then.