Partials/Speed system

See full page: Improving Ship Speed

A ship is either slow or fast natively, the speed can be increased (from slow to fast to fast+ to fastest) using engine synergies, by equipping a turbine (can be equipped in the Reinforcement Expansion) and one or more boilers (Enhanced Kanhon Type Boiler and New Model High Temperature High Pressure Boiler) on a ship.

• As some branching rules are affected by speed, speeding up a fleet can make it follow a different routing.
  • Note, however, that this does not change ship types, initially slow BB and BBV can have fast speed, but still are not FBB.
• BB/BBV that are fast+ can be placed in the escort fleet of STF/TCF (only fast for Warspite Kai).

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
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
	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
	C	SS, SSV, AR	AO: Hayasui LHA: Akitsu Maru
	None	DE	N/A

Speed exceptions
Ships	Speed group	Exception	Notes
All Fast A		Effects at 1-5 & 8-10 unverified yet. +1 fit bonus with the New Model High Temperature High Pressure Boiler at 7+	Stackable
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.
Amatsukaze Kai/Ni Shimakaze Kai	Fast A/B1	Can equip Boilers in the RE