Leavenworth class

The Leavenworth class frigate was a type of Federation starship on active duty during at least the late 23rd century. Construction of the class was authorized in mid-2288 and the first ships of the class were commissioned probably ca. 2291 or 2292. 

The design lineage of the Leavenworths was derived from the heavy cruisers. However, the LN-72 type (or similar) warp nacelles of the Leavenworth class were mounted on pylons similar to those on Excelsiors, albeit positioned downward. (At least one unoriginal critic referred to the Leavenworths as an "Excelsior version of a frigate.")

The primary role of Leavenworth-class frigates was to transport troops and assault fighters into battle. Two full wings of fighters were embarked. Standard crew complement was 533 officers and crew plus 112 surface action specialists.

Ships of the Leavenworth class were heavily armed: three megaphaser units mounted on short pylons above the primary hull, 10 phaser banks and two photon torpedo bays.

Reference

 * Kristiansen, Eric.