Military service of the Klingon Empire. The Klingon Defense Force is responsible for defending the Empire's boarders against enemies and for operating the Empire's space fleet.
Vor'cha-class attack cruiser:
Starship of the Klingon Defense Force. The Vor'cha-class attack cruisers were among the largest and most powerful vessels in the Imperial fleet. In 2367, Klingon High Council leader K'mpec was transported aboard an attack cruiser on his final mission; his plea for Jean-Luc Picard to serve as Arbiter of Succession after K'mpec's death. The Vor'cha-class attack cruiser was designed by Rick Sternbach and built by Greg Jein. It first appeared in "Reuinion".
K't'inga-class battle cruiser:
Conjectural designation for an uprated version of the Klingon D7-type starships.
Large version of the Klingon Bird-of-Prey ship. Three of these vessels arrived and surounded the starships Enterprise-D and C as Enterprise-C was trying to return through the temporal rift. The smaller versions of this ship were called B'rel-class vessels.
Small Klingon Bird-of-Prey with a crew of about a dozen, commonly used as a scout ship. We assume that the Bird-of-Prey in Star Trek III was a B'rel class ship, while the larger versions of that ship sometimes seen on Star Trek: The Next Generation were K'Vort-class vessels.
D7 battle cruiser:
Starships that formed the backbone of the Klingon Defense Force for decades. The D7 type vessels were in service in the 2260's, a design shared with the Romulan Star Empire during the brief alliance between the two powers. These vessels, some 228 meters in overall length, were equipped with warp drive and phase-disrupter armament. By the 2280s, an uprated version, known as a K't'inga-class vessel, was introduced into service. The Klingon battle cruiser was designed by Matt Jefferies and introduced during the third season of the original Star Trek series. A more detailed version was built by Magicam for Star Trek: The Motion Picture, and was reused in Star Trek II, Star Trek VI, as well as Star Trek: The Next Generation. The terms D7 and K't'inga are conjectural.