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A point defense cannon (PDC) is used by all military vessels for defense against missiles and ships.


HammurabiPDC (1)

An example of a PDC extended outward from the hull of the ship on its "arm".

PDCs are turreted rotary autocannons, utilizing a set of more, or less than six barrels. PDCs are laid out on a ship's hull to cover most angles for more effective point defense. Most PDCs are positioned on "arms" that can extend outwards from the hull of the ship to allow sufficient clearance when deployed. Some turrets can also be retracted into the hull and can extend outwards in mere seconds.

PDCs are fire control radar-controlled as even juiced-up human gunners would find it nearly impossible to effectively track and destroy fast targets like missiles. Human gunners do, however, select targets for their guns. PDCs are mainly used against guided ordnance, but they also perform fairly well as close range ship-to-ship weapons and can be used for direct ship-to-surface strikes on personnel. The rounds seem capable of moderate penetration.

Although uncommon, PDCs have been known to jam while in combat.[1][2]

Ships equipped with PDCs:[]

RPG MCRN flag Martian Congressional Republic Navy (MCRN)[]

RPG UNlogo United Nations Navy (UNN)[]

RPG OPA logo Outer Planets Alliance (OPA)[]

Protogenlogofromspacedockvideo Protogen[]

Laconia-mockup Laconian Imperial Navy[]


Donnager Point-Defence

The Donnager employing its Nariman Dynamics 40mm point defense cannons.

PDCs were first seen in use on the MCRN Donnager, which used her numerous PDCs to shoot down a hail of plasma missiles launched by an attacking squadron of six Amun-Ra-class stealth frigates. While most of the torpedoes were shot down, the advanced missiie guidance systems, as well as their sheer number, allowed two to get through and damage the Donnager's reactor. In the ensuing CQB battle, the Donnager used focused fire from her PDCs to destroy at least one assailant. As the Tachi (later to be renamed Rocinante) escaped the Donnager's hangar bay under a hail of small arms fire, it returned fire with its PDCs to wipe out many of the Protogen soldiers that had boarded the Donnager and blow open the hangar door, allowing the ship to escape.

At the assault on Thoth Station, the Rocinante's PDCs were used to intercept torpedoes, destroy an anti-asteroid cannon on the station, and even take out the Amun-Ra-class, the Osiris by riddling it with thousands of rounds. The Osiris also used its PDCs to disable one of the Rocinante's port-side thrusters, hampering her maneuverability during the battle until Amos Burton repaired the damage.

During the sudden and unexpected Ganymede Incident, due to the close proximity and chaos of the incident, PDCs were used as the main weapon by MCRN and UNN ships engaging in combat in Ganymede's orbit, destroying ships on both sides as well as several orbital structures, resulting in a cloud of debris falling to Ganymede's surface and the loss of thousands of military personnel and civilians.

The MCRN Hammurabi opening fire upon hybrid pods with its PDCs.

The MCRN Hammurabi opening fire upon hybrid pods with its PDCs.

During the Io Campaign, the UNN Agatha King used its PDCs to destroy several volleys of missiles fired at it by UNN ships loyal to Admiral Michael Souther in retaliation for UNN Jupiter Fleet Commander Fleet Admiral Augusto Nguyễn's personal destruction carry out of the UNN Jimenez. Later, when the Hybrid pods were launched en masse towards Mars from the surface of Io, the Rocinante and all the UNN and MCRN ships in the area opened fire on the pods with their PDCs attempting to shoot them down with the Agatha King being the only ship not to engage them. However, many pods were able to escape unharmed due to their stealth tech and sheer number. The MCRN Hammurabi's PDCs struck one of the pods before its drive could engage, resulting in the pod crashing into the Agatha King, leading the ship and her crew becoming infected by the Protomolecule.

When the Nauvoo was recovered, Johnson had it renamed the OPAS Behemoth. In addition to attaching several missile pods and railgun turrets, 170 PDCs were mounted to the ship's 2km hull, giving it an impressive defensive coverage.

During the Free Navy conflict, some of the Rocinante's Nariman Dynamics 40mm PDCs jammed while in battle against Free Navy forces.[3][4] These were ultimately repaired, however.

Known Models[]

Mikazuki Munitions PDC

Mikazuki Munitions PDCs.

UN logo Mikazuki Munitions PDC[]

A type of PDC manufactured by Mikazuki Munitions that is used by some older UNN warships. The Leonidas-class is equipped with 20 - 21 Mikazuki Munitions PDCs spread across the hull for proper defensive coverage.

UN logo Redfield Ballistics 40mm PDC[]

Redfield Ballistics 40 mm PDCs

Redfield Ballistics 40 mm PDCs.

A type of PDC manufactured by Redfield Ballistics that is used by some UNN warships. The Truman-class dreadnought is equipped with 42 Redfield Ballistics 40mm PDCs spread across the surface of its hull for maximum defensive coverage with 4 mounted on either side of the bow, 28 on the neck, and 6 at the ends of the Epstein drives. These are not retractable.

Martian Congressional Republic Nariman Dynamics 40mm PDC[]

Nariman Dynamics 40mm PDC

A Nariman Dynamics 40mm PDC.

A type of PDC manufactured by Nariman Dynamics that is used by most MCRN warships. The Morrigan-class patrol destroyer is equipped with two Nariman Dynamics 40mm PDCs on its dorsal hull. A dozen of these guns are employed on the Scirocco-class assault cruiser and full network on the Donnager-class battleship. These are able to be retracted into the utilized ships hull.

OPA logo Kess-Hashari PDC[]

A type of PDC manufactured by Kess-Hashari. The Outer Planets Alliance's retrofitted OPAS Behemoth is equipped with a total of 170 of these weapons to compensate for its large target profile and poor maneuverability.

Protogenlogofromspacedockvideo Bush Shipyards Hyper-cooled PDC[]

PDC turrets specifically designed by the Bush shipyards for Protogen's Amun-Ra-class stealth frigates. Retractable into the hull, they were designed to be rapidly cooled down, and partially retracted for stealth.



  • PDC rounds are repeatedly described as "Teflon-coated tungsten."[Citation needed] While not explained in detail in the books, this fact could make PDC rounds "armor-piercing sub-caliber ammunition;" a long narrow tungsten arrow acting as an armor breaking component, surrounded with light Teflon-edged sabot, providing maximum barrel exit velocity.
    • The Teflon does not affect the ballistics of the round used, but rather allows for harder armor-piercing materials like tungsten to be used without excess barrel wear, as the Teflon lubricates the bullet, allowing it to better engage the barrel without grinding it down.


  1. The Expanse TV Series - Season 6, Episode 1: "Strange Dogs"
  2. The Expanse TV Series - Season 6, Episode 3: "Force Projection"
  3. The Expanse TV Series - Season 6, Episode 1: "Strange Dogs"
  4. The Expanse TV Series - Season 6, Episode 3: "Force Projection"