Star cruiser

The star cruiser was a starship classification for the largest cruisers in Federation Starfleet in the early 25th century. Star cruisers were larger and held the largest crew complements of any other starship type in Starfleet, except for dreadnoughts. Star cruisers dwarfed heavy cruisers by a magnitude. Star cruisers acted as flagships and support for fleets.

In the mirror universe, the Terran Empire swapped the ship classes associated with the regular star cruisers with those of the assault cruisers. 

Specifications
The star cruisers were introduced in the early 25th century. This starship type consisted of individual ship classes. These were designed to be modular, allowing commanding officers to swap sections between ship classes, including the saucer section, secondary hull, nacelle pylons and nacelles.

Star cruisers had a crew complement of 1,000 and access to four cruiser command abilities: strategic maneuvering, shield frequency modulation, weapon system efficiency and attract fire. These abilities allowed a star cruiser to improve maneuverability, deflector shield strength or weapon power; or to attract enemy fire to support weaker fleet ships.

Because of their power, star cruisers were rated tier 5, requiring a commanding officer ranked rear admiral, lower half or higher.

Standard equipment was rated mark VII. Weapon systems included four phaser arrays and photon torpedo launchers each, four aft and fore each. The deflector array, shield array, impulse engine and matter anti-matter warp core were rated Mk VII. All of the equipment was replaceable.

Due to its high mass, a star cruiser's maneuverability was poor. Hull and shields were more resistant than on science vessels and escorts. Weapons were less powerful compared to escorts.

Like all Federation starships of the early 25th century, all star cruisers had access to the Federation transwarp network. All star cruisers commanded by an officer ranked vice admiral or higher was equipped with quantum slipstream drive, and its shuttlecraft were equipped with QSD, too. Star cruisers were capable of speeds in excess of warp factor 9.9. 

In the mirror universe, the Terran Empire called their assault cruisers, star cruisers, and vice versa. 

Star cruiser classes

 * United Federation of Planets:
 * Terran Empire:
 * Terran Empire: