Partials/Speed system

Ship's speed can take the following values:

• Slow (低速)
• Fast (高速)
• Fast+ (高速+)
• Fastest (最速)

Initially, a ship is either slow or fast, the speed can be increased (from slow to fast to fast+ to fastest) using the engine synergy, by equipping a turbine (can be equipped in the expansion slot) and one or more boilers (Enhanced Kanhon Type Boiler and New Model High Temperature High Pressure Boiler) on a ship. The effects are

• Increase in speed, slow ships will be fast and will count as fast for branching rules. It is also assumed that fast+ and fastest will have their own branching rules in the future.
• Devs claim increase in evasion is currently the only effect provided by the higher ship speed. However its magnitude/scope/existence is still investigating by players.

Speed and engine synergy
+13 boilers	+10 boilers	Group/Speed							Equipment evasion	Slots required
		Fast A	Fast B1	Fast B2	Fast C	Slow A	Slow B	Slow 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
0	4	Fastest	Fast+	Fastest	Fast+	Fast	Fast+	Fast	46	5
1	0	Fastest	Fast+	Fast+	Fast+	Fast	Fast	Fast	19	2
1	1	Fastest	Fastest	Fast+	Fast+	Fast+	Fast	Fast	29	3
1	2	Fastest	Fastest	Fastest	Fast+	Fastest	Fast+	Fast	39	4
1	3	Fastest	Fastest	Fastest	Fast+	Fastest	Fast+	Fast	49	5
2	0	Fastest	Fastest	Fastest	Fast+	Fast+	Fast+	Fast	32	3
2	1	Fastest	Fastest	Fastest	Fast+	Fastest	Fast+	Fast	42	4
2	2	Fastest	Fastest	Fastest	Fast+	Fastest	Fast+	Fast	52	5
3	0	Fastest	Fastest	Fastest	Fast+	Fastest	Fast+	Fast	45	4
3	1	Fastest	Fastest	Fastest	Fast+	Fastest	Fast+	Fast	55	5
4	0	Fastest	Fastest	Fastest	Fast+	Fastest	Fast+	Fast	58	5

Speed groups
Initial speed	Group	Ships, classes, types
		Destroyers	Light Cruisers	Heavy Cruisers	Battleships	Carriers	Others
Fast	A	Shimakaze		Tone-class Class, Mogami-class Class		Taihou, Shoukaku-class Class
	B1	Amatsukaze	Agano-class Class		Kongou-class Class, Iowa	Souryuu, Hiryuu, Unryuu, Amagi
	B2	Others	Other CL, CLT	Others	FBB	Fast CVL, Akagi, Katsuragi
	C		Yuubari			Kaga	Fast AV
Slow	A				Yamato-class Class
	B		CT		Other BB, BBV	Slow CVL	Slow AV, AS
	C						SS, SSV, LHA, AR, AO

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