06Reactor compartment — integral reactor: core, steam generators and pressurizer in one vesselPower
07Missile compartment — 16 tubesMission systems
08Outer hull, pressure hull & ring framesStructure
09Battery buffer — 6 MWhPower
10Sail — masts & sensorsStructure
11Autonomous command coreMission systems
12Weapons room & tubesMission systems
13Spherical bow sonarMission systems
14Main ballast tanksStructure
15Towed array & reelMission systems
II · Power & drivetrain
Silence is the whole job.
Electric drive removes the reduction gear, the loudest part of a submarine. Power comes from a life-of-ship reactor, so patrol length is set by maintenance, not fuel.
Natural-circulation reactor and direct drive — rotating view
A tall 120 MWt integral reactor carries its steam generators inside the vessel and circulates by convection at patrol speed, so no coolant pump runs on patrol. Its four-stage 36 MWe turbo-generator feeds a 30 MW motor at 120 rpm, bolted straight to the pump-jet shaft: no reduction gear. The arrangement is generic.
02Natural circulation — riser up the core, downcomer at the wall; sprint pumps only above 25% power
03Steam turbo-generator — 4 stages, 36 MWe
04Condenser — sea-water cooled
05Main switchboard — 6.6 kV, electric drive
06Propulsion motor — 30 MW permanent-magnet, direct drive at 120 rpm
07Pump-jet rotor — 11 blades, in its duct
08Shaft — no gearbox: the loudest part of a submarine, removed
Pump-jet rotor
Power plantPressurized reactor, 120 MWt
Shaft output≈ 30 MW, electric drive
FuelHighly enriched uranium, ≈ 93% U-235
Consumption≈ 5.25 g fissile / hr
Metal content≈ 93% high-yield steel
Naked drivetrain — energy to motion
III · Armament
Sixteen tubes, loaded once, never touched at sea.
Sixteen missile tubes in four quad-packs abaft the sail carry the Trident II D5 family, one missile per tube for the whole patrol, loaded only in port. Four 21-inch tubes hold heavyweight torpedoes for self-defense. Choose a system to watch it fire, or open the magazines to see the tube column and the port load. Release authority stays with humans ashore, always.
All systems stowed; the boat is submerged on patrol
16 Trident tubes in four quad-packs · 4 × 21-inch Mk 48 tubes for self-defense · external decoy launchers · release authority stays with humans ashore
Launchers and mounts
Launcher or mountCountCells or roundsRange classReload
87-inch ballistic-missile tubes (Common Missile Compartment, 4 quad-packs)16 (2 rows of 8)1 missile per tube; the tube is the magazineIntercontinentalNever at sea: in port at a strategic weapons facility wharf, by overhead crane, days per boat
21-inch torpedo tubes (self-defense)4Heavyweight torpedoes in the tubes and on racksShort to mediumFrom the racks at sea: tray and hydraulic rammer, minutes per tube
Countermeasure launchersExternal and internalExpendable acoustic decoysVery shortIn port
Compatible munitions
Strategic
Trident II D5 and D5LE, submarine-launched ballistic missile, three solid stagesIn service
D5LE2 (fleet introduction planned FY2039)In development
Anti-sub and torpedo
Mk 48 Mod 7 heavyweight torpedoIn service
Mk 48 Mod 8In development
Defenses
Expendable acoustic decoys, ADC familyIn service
Mk 58 Compact Rapid Attack Weapon, anti-torpedoIn development
Quieting, depth and manoeuvre: the primary defenseIn service
Not carried
No cruise missiles, guns or air defenseBy design
No autonomous launch, in any tier: crewed weapons authority ashorePolicy
Systems are named by US Navy designation. The launch sequence follows public descriptions at animation pace; the spacing between the two launches shown is illustrative. Nothing about the payload is shown or stated. Sources and checks are listed in BUILD_NOTES.md.
IV · How it is put together
Sixteen tubes in pairs, six modules joined.
Hull cylinders are rolled from plate while sixteen launch tubes are welded separately; the tubes go into the midbody in pairs, six super-modules are joined end to end with the reactor compartment sealed in, then sail, X-stern and pump-jet. The lead boat is planned at 84 months.
Hull cylinders are rolled from plate; sixteen large tubes are welded separately.
Tubes go into the midbody in pairs; modules are outfitted before joining.
Six super-modules are joined end to end; the reactor compartment is sealed in.
The sail, X-shaped stern planes and ducted propulsor are fitted.
The boat floats off, trials alongside, then dives for the first time.
I
Hull cylinders and launch tubes made
II
Tubes set in pairs, outfitted
III
Six super-modules joined
IV
Sail, X-stern and pump-jet
V
Float-off and dive trials
V · Specification
Concept specification.
Design specification for the autonomous ballistic-missile submarine.
Length overall
170.7 m
Displacement (submerged)
20,815 t
Missile tubes
16
Power plant
Pressurized reactor, 120 MWt
Consumption
≈ 5.25 g fissile / hr
Core life
Life of ship
Speed (submerged)
20+ kn
Propulsor
Pump-jet, electric drive
Patrol
Continuous, remote command
Sonar
Spherical bow array
Electric output
≈ 36 MWe, 30% steam cycle
Shaft output
≈ 30 MW, no reduction gear
Natural circulation
No coolant pumps below 25% power; 13% at 8 kn patrol
Battery buffer
6 MWh; 1.3 hr at 8 kn patrol
Metal content
≈ 93% high-yield steel
Crew aboard
0
Onboard compute
Four AI modules and a verifier that must always agree
Modules4 AI modules (navigation & patrol plan; sonar classification; ship control & plant; verifier) + 2 certified safety controllers; the weapons system is separate and under human control ashore
AI throughput20,000 TOPS total (4 × 5,000, INT8 / FP4 sparse)
Memory4 × 128 GB LPDDR6, 600 GB/s per module
Power draw400 W compute; ≈ 0.7 kW with sonar front-ends and 4 mast cameras — 0.002% of the 36 MWe plant
Process node2 nm-class SoCs; safety controllers on a mature 16 nm node, 15-year supply
RedundancyEvery sensor is wired to both module pairs. Each module is primary for its own job and hot standby for its partner; the verifier must agree before any change of depth, speed or course, and any one module can hold the boat safe. A software fault can never drive the submarine outside its certified safe envelope: two SIL 3 controllers own reactor protection, depth and ballast on their own depth gauges, plane and rudder angle sensors, shaft encoder and reactor instruments. Weapons release is never an onboard software decision.
SensorsSpherical bow array, flank and towed arrays, 4 mast cameras on an automotive Ethernet camera switch, inertial navigation, 2,400 plant sensors
LinkVery-low-frequency receive on patrol; satellite at communication depth; the patrol plan is carried aboard. Motor drives close their own current loop at 1 kHz; every safety loop closes aboard.
Service lifeThe boat serves 42 years on one core. Compute is a line-replaceable unit, swapped at mid-life.
On patrol the boat listens, stays quiet and follows a plan set ashore. Its modules classify sonar contacts and keep the boat within its box; a verifier module must agree with every manoeuvre. The weapons system is separate, and release authority stays with humans ashore.
Today vs IC
Power and crew: today’s missile submarine beside the IC design
Today · ballistic-missile submarineIC design
Size and tubes170.7 m, 18,750 t, 24 tubes; the successor in build is 20,815 t with 16 tubes170.7 m, 20,815 t, 16 tubes
ReactorPressurized-water reactor, rating not published; the successor gets a life-of-ship core of ≈ 42 years120 MWt integral reactor, natural circulation on patrol, life-of-ship core
Drive2 geared steam turbines, ≈ 26 MW → reduction gear → 7-blade propeller; the successor moves to electric drive36 MWe turbo-generator → 30 MW direct-drive motor at 120 rpm → 11-blade pump-jet