Manufacturing line/Submarines/Extra-large unmanned undersea vehicle
Autonomous · Submarines

Extra-large unmanned undersea vehicle

A small, long-range unmanned submarine, built one a week.

Phase 7 · 2033+Concept design
Length
26 m
Endurance
Months
Energy use
≈ 16 kWh / hr
Crew
0
I · Blueprint
Side elevation, live systems
2.5 m5 m7.5 m10 mDEPTHAABBCCAcoustic modemAutonomy & nav electronicsFree-flooding bayPayload modulePayload railsFree-flooding fairingBattery moduleDC busGeneratorDiesel engineInverterShaft sealStator vanesLifting pointSnorkel mastMast fairingPayload bay doors26 m length overall34 ft payload module · up to 8 t040506070308010209
SECTION A–A · BATTERY SECTIONØ 2.4 mFairingFree-floodKeelBattery housingBattery moduleDC busSECTION B–B · PAYLOAD BAYBay doorsFree-flooding bayKeel framePayload modulePayload railsGeneric payloadSECTION C–C · TAIL, LOOKING FORWARDX-stern fins ×4Tail coneMotorShaftSections look forward. Diameter 2.4 m to scale; internal arrangement generic, drawn as a modular payload-section layout.
01Pump-jet & X-sternPropulsion
02Propulsion motor & shaft sealPropulsion
03Li-ion battery modules, with inverter & DC busPower
04Communications mastStructure
05Pressure-tolerant hull — free-flooding fairingStructure
06Modular payload bayPayload
07Forward sensor arrayPayload
08Diesel generator & snorkel mastPower
09Autonomy core — 2 light AI modules, safety controller, navigationPayload
II · Power & drivetrain

A diesel, batteries and patience.

A diesel generator recharges Li-ion battery modules when the vehicle is surfaced or at snorkel depth; submerged, the batteries alone feed a single motor at low speed. No reactor and no air-independent engine: diesel, batteries and a low-drag hull.

Diesel generator, battery and motor — rotating view
A four-cylinder turbocharged diesel, drawn with pistons, rods and crank webs moving, turns a 250 kW generator when the vehicle is at snorkel depth; the exhaust leaves through the mast (top left). The 2 MWh battery and inverter feed a 150 kW motor and the pump-jet rotor at right; submerged, the battery alone runs everything.
01Diesel engine — 4 cylinders, turbocharged, 1,800 rpm, snorkel only
02Generator — 250 kW, recharges the battery in ≈ 9 hr
03Battery — 2 MWh Li-ion, 8 t, ≈ 5 days submerged at 4 kn
04Inverter & DC bus — 700 V
05Propulsion motor — 150 kW permanent-magnet at 300 rpm; ≈ 6 kW at 4 kn
06Pump-jet rotor — 7 blades, in its duct
07Snorkel mast — air in, exhaust out
08Hotel load — ≈ 10 kW: compute, sensors, pumps
Pump-jet rotor
Power plant250 kW diesel generator + 2 MWh Li-ion battery
Shaft output150 kW motor; ≈ 6 kW at 4 kn
FuelDiesel (generator only)
Consumption≈ 16 kWh / hr at 4 kn
Metal content≈ 60% (steel & composite)
Naked drivetrain — energy to motion
Conceptual · not to scaleSnorkel airExhaustRuns surfaced orat snorkel depthRectifierLI-ION BATTERY SECTIONBMSDC +DC −ContactorAutonomy &sensorsIGBT half-bridges ×33-phase ACStator windingsRotorBearingHull · shaft sealStatorRotorDiesel generatorBattery modulesDC busInverterPM motorShaftPump-jet
III · Armament

One bay, eight tonnes, laid where a commander says.

The 34-foot payload module carries up to eight tonnes. Its first weapon mission is mine laying: the vehicle creeps along the bottom and releases each mine at a point a human authorized before it sailed. It carries no guns and no missiles. Watch a lay, or open the module to see how the mines are stowed, released and reloaded ashore.

Payload bay closed; the vehicle is on transit
34-ft payload module, up to 8 t · encapsulated anti-submarine mine and seabed mine (in development) · standoff torpedo pod announced · no guns, no missiles
Launchers and mounts
Launcher or mountCountCells or roundsRange classReload
Payload module, 34 ft (10.4 m), about 2,000 ft³1Up to 8 t of mines or effectors; the number per sortie is not publishedLaid in placeAshore only: the whole module is swapped at the pier
Standoff heavyweight-torpedo deployment system (announced 2026)1 (option)Heavyweight torpedoes in the moduleStandoffAshore, by module swap
Guns, missiles, air defenseNone———
Compatible munitions
Mines
Hammerhead, encapsulated anti-submarine torpedo mine (order raised 2026)In development
Clandestine Delivered Mine, seabed mine from mobile-mine partsIn development
Hunter expeditionary mining payload (announced 2026)In development
Anti-sub and torpedo
Mk 54 lightweight torpedo, inside the encapsulated mineIn service
Standoff heavyweight-torpedo pod (announced 2026)In development
Defenses
Low signature, depth and expendability; no defensive payload publishedBy design
Decoy canisters in the payload bay (projection, 2030s)In development
Authority
Release only on a human-authorized lay plan, under DoD Directive 3000.09Policy
The bay release mechanism, mine sizes and the number per sortie are not published: the release, sink rate and spacing shown are illustrative. Nothing about how a mine acts is shown. Sources and checks are listed in BUILD_NOTES.md.
IV · How it is put together

Housings on a keel frame, pier-side launch.

A keel frame carries the sealed battery, electronics and machinery housings inside a free-flooding fairing; sections are butt-joined on the frame, then masts, fins and sensors go on. A pier crane sets it in the water with no host ship.

A keel frame carries sealed housings; the rest of the hull floods freely.
Battery housings fill with modules; the payload bay gets rails and doors.
Generator, motor and tail sections are joined to the battery section.
Masts, four stern fins, the pump-jet and the forward sensors go on.
A pier crane sets it in the water; it trims, dives and sails itself.
I
Keel frame and pressure housings
II
Battery and payload sections outfitted
III
Power and tail sections joined
IV
Masts, fins and sensors fitted
V
Pier-side launch and dive trials
V · Specification

Concept specification.

Design specification for the autonomous extra-large unmanned undersea vehicle.

Length overall
26 m
Displacement
85 t
Payload bay
34 ft module, up to 8 t
Power plant
250 kW diesel generator + 2 MWh Li-ion battery
Consumption
≈ 16 kWh / hr at 4 kn
Endurance
Months
Range
6,500 nm
Shaft output
150 kW motor · ≈ 6 kW at 4 kn
Submerged endurance
≈ 5 days at 4 kn on battery
Recharge
≈ 9 hr at snorkel depth
Propulsor
Pump-jet
Comms
Mast + acoustic link
Build rate
1 per week
Top speed
≈ 12 kn; 4 kn cruise
Metal content
≈ 60% (steel & composite)
Crew
0
Onboard compute
Two light AI modules, because every watt is range
Modules2 light AI modules + 1 certified safety controller
CPU16 cores (2 × 8) + 2 lockstep real-time cores per module
AI throughput3,000 TOPS total (2 × 1,500, INT8 / FP4 sparse)
Memory2 × 64 GB LPDDR6, 300 GB/s per module; 4 TB mission log
Power draw70 W compute; ≈ 110 W with the safety controller, 4 cameras and the sonar front-end — 0.7% of the 16 kW average load
Process node2 nm-class SoCs; safety controllers on a mature 16 nm node, 15-year supply
RedundancyEvery sensor is wired to both modules. Each module is primary for its zone (vehicle, or mission and payload) and hot standby for the other, and each restarts from a cold image. A software fault can never drive the vehicle outside its certified safe envelope: the SIL 3 controller, on its own depth gauges, fin encoders, leak detectors and battery monitors, surfaces the vehicle, drops ballast and calls home by itself. Loss of both modules ends the mission safely.
SensorsForward-looking and side-scan sonar, 4 cameras (visible and low-light) on an automotive Ethernet camera switch, inertial navigation with Doppler log, 300 plant sensors
LinkSatellite and radio through the mast when surfaced; acoustic link to other vehicles; the mission plan is carried aboard. The motor drive closes its own current loop at 1 kHz; every safety loop closes aboard.
Service lifeThe vehicle serves 20 years. Compute is a line-replaceable unit, swapped at mid-life.
At 4 knots a 110 W computer is 0.7% of the vehicle’s load, so two light modules are the right size: enough for navigation, obstacle avoidance and payload handling with a hot standby, and small enough that months of endurance are set by diesel and batteries, not by silicon.
Today vs IC
Power and range: today’s extra-large undersea vehicle beside the IC design
Today · extra-large unmanned undersea vehicleIC design
Size26 m with a 34 ft payload module, 85 t26 m, Ø 2.4 m, 85 t, 34 ft payload module up to 8 t
PowerDiesel generator recharges Li-ion batteries at snorkel depth; outputs not published250 kW diesel generator + 2 MWh Li-ion battery → 150 kW motor on a 700 V bus
Speed8 kn top, 3 kn typical≈ 12 kn top, 4 kn cruise
Range and endurance6,500 nm; months6,500 nm; ≈ 5 days submerged per charge, ≈ 9 hr to recharge; months
Build rate≈ 1 per year planned, ≈ $113–120 M each1 per week
Crew0 aboard; run by a shore squadron0 aboard; fleet plan re-solved by The Brain each time a vehicle surfaces
The IC column is the design shown on this page. Sources for the Today column are listed in BUILD_NOTES.md.
Runs on The Brain
Every mission of this vehicle is planned by The Brain’s orchestration layer, mirrored in the fleet’s digital twin, and re-planned each time it surfaces.
See how it works →
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