D7 Class Battle Cruiser

a D7 Class Battle Cruiser

The D7 Class Battle Cruiser was a 23rd century warship that was originally designed by the Klingons that was also utilized by the Romulans during the late-2260s.

History

The D7 class Klingon battle cruiser served as the backbone of the Klingon Imperial Fleet for several years during the 23rd century. (TOS: "Errand of Mercy" remastered, etc.)

By 2267, they were prominently featured in the Klingon-Federation Cold War, where they posed a serious threat to the security of Starfleet and the Federation. (TOS: "Elaan of Troyius"; TAS: "More Tribbles, More Troubles")

The Romulan Star Empire later began using the same the design by 2268. (TOS: "The Enterprise Incident")

According to the Star Trek Chronology the line regarding a Romulan-Klingon Alliance was added to TNG: "Reunion" to explain the Romulan use of D7s.

The K't'inga Class Battle Cruiser began to replace the D7 class during the 2270s. The D7 was finally "retired decades" prior to 2377. (Star Trek: The Motion Picture; VOY: "Prophecy")

Interest in these vessels by the Federation continued to appear well into the 2370s, as data on this class was commonly found within numerous Starfleet files. (TNG: "The Naked Now", "The Last Outpost", "Conspiracy"; VOY: "Drone", "The Voyager Conspiracy")

Physical arrangement

The D7 class was almost predatory in its appearance, with a spread-wing primary hull, long neck and head-like command pod. The early Romulan variants had a large bird-of-prey design painted on the hull, identical to what was found on the Bird-of-Prey. (TOS: "The Enterprise Incident") Other Romulan D7s had red and yellow feather-like detailing painted on the upper wing and nacelle pylon. (TAS: "The Survivor", "The Practical Joker")

The D7 bird-of-prey paintings have only appeared in the D7s of the remastered version of "The Enterprise Incident".

The bulk of the ships overall mass was incorporated in the aft section of the ship. The bridge was located on the bulbous head, which was separated from the aft section by a relatively thin neck that flared out into the wings. Jutting from below these wings were a pair of outboard warp nacelles. The ship's impulse Engines were located on the caudal section of the ship. (TOS: "Elaan of Troyius")

This design had evolved from a classic design lineage dating back well into the 22nd century with the early D5 Class Battle Cruisers. (ENT: "Judgment") In terms of dimensions, it was comparable in size to the Federation's Constitution Class starship. (TOS: "The Enterprise Incident")

Tactical systems

During the mid-23rd century, the D7 class posed a significant threat to the Federation with the classes impressive armament consisting of dual wing-mounted Disruptor Cannons, a forward-mounted Phaser emitter, and a forward launcher capable of firing Photon Torpedoes as well as magnetic pulses. (VOY: "Prophecy"; TOS: "Errand of Mercy"; TAS: "More Tribbles, More Troubles")

Unlike preceding and proceeding classes, the D7 does not appear to have possessed any aft firing torpedo tubes.

While often viewed as a threat to a Constitution Class starship a D7 cruiser, under certain circumstances, it was possible for a Constitution to destroy a single D7 with a barrage of phaser fire. Following such an instance at the outbreak of the Federation-Klingon War in 2267, the USS Enterprise encountered a fleet of eight D7s, which was considered by Captain James T. Kirk to have superior odds. Despite these odds, Hikaru Sulu was confident the Enterprise could have defeated them. (TOS: "Errand of Mercy" remastered)

In 2269, the Klingons developed a prototype weapon, described as a Projected Stasis Field, which was first encountered on the IKS Gr'oth by the Federation. The field could be projected in up to three different directions at one time. The weapon, which was extremely powerful, was capable of completely paralyzing an enemy vessel, including all its vital systems. It was however equally crippling to the firing ship itself. Ultimately, it was determined by the Federation that this was so impractical in standard combat, that it posed no real threat. (TAS: "More Tribbles, More Troubles")

By the late 24th century, these vessels were considered rather antiquated, and were identified as being inferior in firepower to a Federation Intrepid Class starship. (VOY: "Prophecy")

Cloaking device

Like its predecessor, the Romulan Bird-of-Prey, the Romulan D7 was equipped with cloaking technology.

Klingon ships were outfitted with cloaking devices as late as 2269. One of the first Klingon vessels to acquire the new technology was the IKS Klothos. (TAS: "The Time Trap"; DS9: "Once More Unto the Breach")

According to the Star Trek: The Next Generation Technical Journal the cloaking device was acquired by the Klingons as an exchange to several D7s with the Romulans during the Romulan-Klingon Alliance.

Propulsion systems

Some Klingon ships in the 23rd century were equipped with an S-2 Graf Unit, which was roughly equivalent to the warp drives in the Federation's Constitution-class starships. The warp drive of the D7 enables it to reach the speed of warp 9. (TAS: "The Time Trap"; TOS: "Elaan of Troyius", "The Enterprise Incident")

The only glimpses we have seen of the D7's warp core were briefly shown in "More Tribbles, More Troubles".

In addition, D7s impulse drive consisted of four-port engines, presumably giving the ship enhanced maneuverability at sublight speeds. (TOS: "Elaan of Troyius" remastered) [edit] Other systems

Romulan D7s were outfitted with food synthesizers. (TAS: "The Practical Joker")

Interior design

Crew complement

The average crew complement of a Klingon D7 was comparable to a Constitution-class, and consisted of around 430. (TOS: "Day of the Dove")

Main bridge

Referred to by the Romulans as "Control Central", the bridge was the nerve center of the D7 class. (TOS: "The Enterprise Incident")

Conference room

The conference room was used as a meeting place for the ship's senior staff for mission briefings. It contained a triangular table embossed with the emblem of the Klingon Empire, with each side of the table having its own set of chairs. Surrounding the table are various computer consoles. (TAS: "The Time Trap")

Mirror Universe

In the Mirror Universe the Klingon-Cardassian Alliance was still using Modified D7s. A large number of them were destroyed by the ISS Rosenante when they deployed the Omega Device which also destroyed Sunali II.