Taigei-class

Diesel-electric attack submarine class jointly built by Mitsubishi Heavy Industries and Kawasaki Heavy Industries for the Japan Maritime Self-Defense Force, the successor to the Soryu-class. It is the first Japanese submarine class to use lithium-ion batteries in every hull rather than air-independent propulsion, extending submerged endurance.

In service since 2022 · 1 operator countries

Compiled from public sources ·primary reference ↗ ·last verified 2026-07-02

3,000

crew

Procurement snapshot

Availability & export

National export licensing

Subject to Japan export-control approval; verify eligibility with the manufacturer.

Channel: Direct commercial / G2G

Fielded & proven

Limited · 1 operator

In service since 2022. Status: active · ~3 built.

Lifecycle cost (est.)

No public unit price to model from.

Interoperability

No standardised NATO calibre / datalink detected in public specs.

Derived guidance from public data — export regime by country of origin, lifecycle from the GAO ~30% acquisition rule. Verify eligibility, pricing and offsets with the manufacturer and your acquisition authority.

Full specifications

Firepower

Armament, payload and guidance.

Torpedo tubes Number of torpedo tubes (submarines and some surface ships).: 6

Stronger than 53% of submarines

Physical

Dimensions, weight and crew.

Length Overall length including gun/probe where applicable.: 84 m

Naval

Displacement, speed, endurance and diving depth.

Displacement Standard displacement in tonnes — the ship’s size class. Larger hulls carry more but cost more and are less agile.: 3,000 t
Submerged speed Maximum speed while submerged (submarines). Higher is faster underwater.: 20 kn

Stronger than 29% of submarines
Complement Crew size. Fewer eases manning cost; more may indicate a larger, more capable platform.: 70
Propulsion plant Machinery type — nuclear reactor, gas turbine (COGAG), CODAG, diesel-electric, AIP.: Diesel-electric with lithium-ion battery storage

Program

Cost, production scale and operators.

Units built Total production run. Higher means proven manufacturing, mature logistics and spares availability.: 3

Stronger than 25% of submarines
Operator countries Number of countries operating the system. More operators means broader support ecosystem.: 1

Stronger than 39% of submarines

Specifications compiled from public Kawasaki Heavy Industries and reference sources ↗. Published defense figures are approximations — treat comparisons as directional. Last verified 2026-07-02.

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