The SMC Carrier/Destroyer is a starship class used during the second Invasion of Stroggos. It can be seen throughout the events of Quake 4. One ship of this class, the USS Patton, transports the members of Rhino Squad to Stroggos.
Little is known about this starship class. It is by far larger than cruisers like the USS Hannibal. The ship can be subdivided into three sections: a wedge-shaped front section that seems to house many crew quarters and makes up about one third of the ship's length; a long middle section with a lot of hangar bays for Dropships; and an engine section that houses the ship's sublight propulsion systems. While the first two sections are built rather slenderly to offer very few surface for attacks, the engine section is about three times as broad as the rest of the ship.
In the intro of Quake 4, dozens of these ships are seen in Stroggos' orbit; therefore, it is likely that this class has already been used by the SMC before the war with the Strogg.
Effectively, these ships seem to be a hybrid between a carrier (large hangar bays) and a destroyer (heavy armor plating and powerful weapons): this versatility can be seen very well during the intro and the first few levels of Quake 4, where those ships first deploy large waves of Dropships and later participate in bombardments of Stroggos' surface.
Very little is known about this class's armament. However, ships of this class have at least four energy-based weapon arrays. These are placed in a very strange manner: two at the underside of the front section and the other two at the underside of the engine section, facing the other array. Therefore, these weapons can never fire in a straight line (as they would hit the ship itself); instead, they fire downwards or to the sides of the ship, making them ideal for bombardments or broadsides in fleet actions, these are probably used to destroy AA cannons, like the one found in MCC landing site, or provide cover to troops on the ground when they face fortifications or large enemy units.
Aside from the bombardment arrays, and a small top mounted turret no other weapons can be seen on these ships. It is likely that they possess missile batteries and smaller gun turrets for point-defense and ship-to-ship combat purposes. It is assumed that these ships are still in orbit above Stroggos after Operation: Last Hope is completed.