Klingon starships
In the Star Trek franchise, the Klingon Empire makes use of several classes of starships. As the Klingons are portrayed as a warrior culture, driven by the pursuit of honor and glory, the Empire is shown to use warships almost exclusively and even their support ships, such as troop transports and colony ships, are armed for battle. This contrasts with the exploration and research vessels used by Starfleet, the protagonists of the franchise. The first Klingon ship design used in The Original Series, the D7-class battlecruiser, was designed by Matt Jefferies to evoke a shape akin to that of a manta ray, providing a threatening and instantly recognizable form for viewers. The configuration of Jefferies's design featured a bulbous forward hull connected by a long boom to a wing-like main hull with the engine nacelles mounted on each wingtip. Though a variety of Klingon ships have appeared in Star Trek, their design generally conforms to this style. Most Klingon vessels were physically built as scale models, although later computer-generated imagery was used to create the models. In recent years, many of the original studio models have been sold at auctions.
All Klingon ships are equipped with some form of sublight engine, and most of these ships are equipped with superluminal propulsion technology called warp drive. Klingon vessels are usually depicted as being heavily armed, equipped with particle beam weapons called disruptors and photon torpedoes, an antimatter weapon, as primary offensive weaponry. Later Klingon ships use cloaking devices. For The Next Generation and Deep Space Nine, Klingon ships were designed by Rick Sternbach to reflect technology exchanges as a result of an alliance between the Klingons and Starfleet. In the prequel television series Enterprise, Klingon ships are designed to appear more primitive than those chronologically later in the franchise. The interior of Klingon vessels is utilitarian in nature: this is intended to mimic an old submarine. Klingon ship names are usually preceded by the prefix "IKS", an abbreviation for "Imperial Klingon Starship".
''The Original Series'' era
D7-class
The D7-class battlecruiser is the first Klingon starship observed in the Star Trek franchise. The vessel was designed by Matt Jefferies to be distinctive and quickly recognized by viewers. As Jefferies wanted the D7-class to appear "threatening, even vicious", the design was modeled on a manta ray in both basic shape and color. The spread-wing primary hull, long neck and bulbous command module configuration of the D7-class became the basic blueprint for Klingon vessels in the later television series. Jefferies's original model for the D7-class now resides in the Smithsonian Institution's National Air and Space Museum, along with the original studio model for USS Enterprise.The D7-class model was originally produced for The Original Series episode "Elaan of Troyius"; however, as the episodes were not aired in their production order, the vessel first appeared in "The Enterprise Incident". It is shown to be armed with several disruptor banks that fire in pulses, and in the remastered version, with a torpedo launcher in the forward module. In one episode of The Animated Series, "More Tribbles, More Troubles", a D7-class battlecruiser is equipped with an experimental stasis weapon, capable of paralyzing target vessels. The vessel possesses both impulse engines and warp drive, allowing for faster-than-light travel. While Klingon vessels in the television series set after The Original Series possess cloaking devices, the Klingon D7-class does not at first. This is changed after "The Enterprise Incident", several D7-class battlecruisers are shown under Romulan control as the result of a technology exchange between the Romulans and the Klingons; these vessels use a cloaking device.
The appearance of the D7-class has been revisited several times in the Star Trek series; an entirely new studio model was created by Greg Jein for the Deep Space Nine episode "Trials and Tribble-ations". With an overall green hue, this model had a significantly more detailed hull in comparison to the bland gray of the original. A D7-class ship also appears in the Voyager episode "Prophecy"; however, as a CGI model of Jein's model was not available, the ship was instead portrayed with a CGI model of the K't'inga-class battlecruiser. The D7-class was again revisited for the remastered version of The Original Series, in which Michael Okuda created a new CGI D7-class model, with improved hull detail and Romulan bird markings for the D7-class vessels in "The Enterprise Incident". This remastered D7-class was digitally inserted into episodes earlier than their original appearances.
''K't'inga''-class
An upgrade of the design used for the D7-class vessel, the K't'inga-class battlecruiser was first conceived for use in the pilot episode of Star Trek: Phase II. When Phase II was abandoned, the story of the pilot was adapted for Star Trek: The Motion Picture, where three K't'inga-class battlecruisers are used in the opening scenes. Andrew Probert is credited as the designer of the K't'inga model in its design patent, while the class name was given by Gene Roddenberry in his novelization of The Motion Picture. Although sharing a nearly identical configuration with the D7-class, the primary difference in the K't'inga-class is the level of detail on the hull, enhanced to make the model appear more believable to viewers on screen. The configuration of the vessel's impulse engines also differs from that of the D7-class. The K't'inga model was later revisited for Star Trek VI: The Undiscovered Country, in which Industrial Light & Magic enhanced the original studio model with glowing engine nacelles and changed the color from muted gray-greens to light gray with gold accents and maroon paneling. ILM's alterations were meant to "contrast... with the Enterprise-A, which is very smooth and monochromatic and cool, while this Klingon ship is very regal and ostentatious and warm". A CGI version of the ship, with a slightly modified nacelle design, was created for the later seasons of Deep Space Nine; this particular model was erroneously used to represent older Klingon ships in the Voyager episode "Prophecy" and the Enterprise episode "Unexpected". The original studio model for the K't'inga-class battlecruiser was later sold in a 2006 Christie's auction for US$102,000.The K't'inga-class battlecruiser has similar armaments to the D7-class battlecruiser, with a photon torpedo launcher in the forward module and six disruptor cannons. In addition, the ship possesses an aft torpedo launcher and can fire a powerful disruptor beam from the forward module. The Voyager episode "Flashback" also shows the K't'inga-class using concussion weapons. Unlike the D7-class, the K't'inga-class uses a cloaking device. In The Next Generation episode "The Emissary", these ships are used as sleeper ships, which could travel for decades with its crew in suspended animation. However, the class is equipped with both impulse engines and warp drive. The class is stated to have a crew of 800 and a length of. The interior of the battlecruiser was designed by Douglas Trumbull, with the intent of appearing like "an enemy submarine in World War II that's been out at sea for too long". The K't'inga-class is used extensively throughout the Star Trek series, appearing from the first feature film set in 2273 to the closing episodes of Deep Space Nine set in 2375, often appearing as a ship of the line in battle scenes.
Bird-of-Prey classes
The Bird-of-Prey is one of the most common Klingon ships seen in the Star Trek franchise. Introduced in Star Trek III: The Search for Spock, the Bird-of-Prey has featured in five of the films and frequently appears in The Next Generation and Deep Space Nine. Industrial Light & Magic designed and built the Bird-of-Prey for Star Trek III, assisted by the film's director, Leonard Nimoy. In early drafts of the script, the Bird-of-Prey was to be a Romulan vessel; although this idea was later dropped, the Bird-of-Prey maintained its cloaking device as a plot point in the film and the Romulan bird feather patterns on its wings were kept. The Bird-of-Prey is the first Klingon vessel depicted with a cloaking device; all classes chronologically later in the series would also use a cloaking device. The wings of the Bird-of-Prey are able to move, lowering to attack, maintaining just above horizontal in flight mode and raising high when the ship lands. However, as the studio model's mechanism for moving the wings broke, in later Star Trek series' episodes the wings are usually fixed in either flight mode or attack mode. This was not rectified until the creation of a CGI model for the vessel. The studio models for the Bird-of-Prey were sold in the 2006 Christie's auction; the original model sold for US$307,200, while an enlarged wing, used for close-up shots in Star Trek V: The Final Frontier, was sold for US$8,400. The Boeing Bird of Prey developed by McDonnell Douglas's Phantom Works division was named after the Klingon Bird-of-Prey.Although several variants are seen throughout the franchise, design notes state that the Bird-of-Prey has two main classes: the B'rel-class and the K'Vort-class. Both classes used the same studio model, differing in sizes in proportion to other starships depending on variant. The B'rel-class is a scout vessel, used for espionage, skirmishes and raids, while the K'Vort-class is a light cruiser. Both classes are armed with disruptor cannons mounted on the tips of the wings and a forward torpedo launcher. Likewise, both classes are equipped with cloaking devices and are capable of impulse and warp speeds. These design notes for the show hold that with a crew of only 12 and a length of, the B'rel-class is far smaller than the K'Vort-class, which measures and possesses a crew of around 300. In its onscreen appearances, however, the Bird-of-Prey model was not scaled consistently to these notes, creating the impression of ships both far larger and smaller than the design notes intended. The interior of the Bird-of-Prey is similar to that of Douglas Trumbull's submarine-like designs for the K't'inga-class; some Birds of Prey are even shown with periscopes to allow the captain to personally target weapons. Despite relatively light armaments, Birds of Prey are shown to be effective craft; both the USS Enterprise and USS Enterprise-D are destroyed in part due to the activity of Birds of Prey. Most cloak-capable Star Trek vessels are unable to use weapons when cloaked; the film Star Trek VI: The Undiscovered Country features a modified experimental Bird-of-Prey that appeared to be able to fire torpedoes while cloaked although later observations revealed that the ship briefly decloaked.