The uncloaking of a warbird of this type in 2364, during an encounter with the USS Enterprise-D on the edge of the Neutral Zone, signaled the end to fifty three years of Romulan isolation. (TNG: "The Neutral Zone") Over the next ten years, these warbirds, under the command of both the Romulan military and Tal'Shiar, would participate in numerous encounters with Starfleet and the Dominion. By 2374, they were prominently featured in the Dominion War, where they were instrumental in forcing the Dominion fleets back time and again. The design saw action during the First and Second Battles of Chin'toka, as well as the final showdown of the conflict, the Battle of Cardassia. (DS9: "Tears of the Prophets", "The Changing Face of Evil")
At least four warbirds were used in the Battle of the Omarion Nebula, joined with at least twelve Cardassian Keldon class cruisers in a combined fleet of twenty ships. The entire fleet was ambushed and destroyed by a fleet of 150 Dominion ships. (DS9: "The Die is Cast") At least seven warbirds were present in the Federation Alliance fleet at the Battle of Cardassia. One is known to have been destroyed and at least five were seen to have survived. (DS9: "What You Leave Behind")
The D'deridex-class warbird was classified as a battle cruiser by Starfleet. Using a forced quantum singularity as a power source and the latest in Romulan cloaking technology, the D'deridex was not only one of the most advanced vessels in the Romulan Star Empire, but also in the Alpha Quadrant. These warbirds were roughly twice as long as a Federation Template:ShipClass starship with a lower overall maximum speed. (TNG: "The Neutral Zone", "Tin Man")
The outboard plan of the warbird's design incorporated a unique horizontally split-"shell" hull design, with a prominent forward section. The bulk of the ships overall size was incorporated in the open-shell, which resemble two separate "wings" that meet at either side at the warp nacelles, at the "tail" and off the "neck", which was connected to the "head" or primary forward hull section. The "head" featured the bridge, main engineering and a majority of the primary weapon systems of the vessel. (TNG: "The Neutral Zone", etc.)
The primary directed energy weapons array of a warbird was located in its "head", and consisted of a disruptor array, capable of firing both beams and pulses, which also appears to have been shared with a torpedo launcher. (DS9: "The Die is Cast"; TNG: "Face of the Enemy", "Timescape"; VOY: "Message in a Bottle") Some warbirds have also been known to be equipped with phasers. (TNG: "Contagion")
Three additional weapon arrays were located, one each, along the top of the upper "neck" support, along the bottom of the lower "neck" support, and at the tip of the "nose". (TNG: "Contagion", "Unification II"; DS9: "What You Leave Behind")
Like earlier Romulan ships, D'deridex-class warbirds were equipped with cloaking devices, which protect them from detection in most evasive situations. Like all cloaking devices, the D'deridex-class could utilize them when in defensive situations or combat situations. However, cloaked warbirds radiated a slight subspace variance at warp speeds; therefore ships traveling at speeds above warp 6 ran a much greater risk of being detected through their cloak. (DS9: "The Search, Part I", "The Die is Cast") There were other unconventional means to penetrate the warbird's cloak. While traveling under cloak, all electromagnetic emissions, including communications, aboard a warbird were carefully monitored. (TNG: "Face of the Enemy")
The warbird utilized a forced quantum singularity as a power source. If that system was not functioning perfectly, or was damaged even slightly, it might have shown through the cloak as a magnetic disturbance of some kind. The destruction of the engine core of a D'deridex-class warbird usually led to the complete destruction of the entire ship.
In order for a warbird to remain undetected while under cloak, the radiative emissions from the warp engines had to be precisely balanced. A slight misalignment in any of the warbirds' nullifier cores would create a small magnetic disturbance in space whenever the ship was in motion. This could make the ship detectable while cloaked. The effect of this disturbance, when it occurred, appeared intermittently as a polarized magnetic distortion. (TNG: "Face of the Enemy")
The use of the confined singularity limited the warbird's overall maximum speed. For a warbird to match the maximum speed of a Galaxy-class starship, it needed to exceed its engine output by 30%. Doing this would typically cause the warbird's warp drive to sustain irreparable damage. (TNG: "Tin Man")
The confined singularity could occasionally cause time shifts into the future. This occurred to Miles O'Brien for a brief period. As a result of this effect, he was able to prevent an attack on Deep Space 9 by a Romulan warbird. Also, if the singularity signature was carefully scanned, it could be monitored through the cloak. (DS9: "Visionary")
The primary color scheme aboard warbirds was distinctively beige and green-gray or teal.
Located in the front of the bridge, against the forward bulkhead, was the ship's main viewscreen.
Directly behind the viewscreen, and to the left, was the location of the pilot's console, which contained helm (and possibly navigator) functions. In some ships, the pilot stood at his console; in others the pilot was allowed a chair.
The command chair was located near the rear of the bridge on a raised platform. Around the perimeter of the command chair were various stations. (TNG: "Contagion", "Face of the Enemy"; DS9: "The Die is Cast")
Adjacent to the bridge was the commander's ready room or command center. Although appearing to vary by ship, one style included (but was not limited to) a large desk and couch, with removable table and a window viewing into space. (DS9: "Improbable Cause", "The Die is Cast")
In some cases, ready rooms functioned as command centers, and included monitors and display consoles. This allowed the commander to monitor the control of ship or fleet activities without actually being on the bridge. (TNG: "Redemption II")
The Wardroom was the conference or officers' room connected to the main bridge by a set of doors. Its function was similar to that of an observation lounge, but also served as the dining area for the ship's senior officers. (TNG: "Face of the Enemy")
The engine room section was located at the ventral base of the forward "head" of the warbird. Its layout was similar to that of a Galaxy-class starship, with primary situation station in the center of the room, and associated consoles along the walls surrounding the room.
One outstanding difference between the main engineering of a warbird and other Romulan starships, from those of the Federation and Klingons, was the absence of a large matter-antimatter reactor core. In place of this bulky component, the Romulans had a wall compartment, which contained their Romulan engine core. (TNG: "Timescape")
The crew quarters aboard a warbird were located on the ship's "C" Deck. They were sparsely furnished, with a table and chairs in the center of the floor, and a set of bunk beds incorporated into the walls. Crew quarters could also have force fields integrated in and around their bulkheads. (DS9: "The Die is Cast")
- IRW Belak
- IRW Decius (illusory)
- IRW Devoras
- IRW D'ridthau
- IRW Haakona
- IRW Khazara
- IRW Makar
- IRW T'Met
- IRW Terix
- "The Neutral Zone"
- "Where Silence Has Lease" (illusionary)
- "The Schizoid Man"
- "Peak Performance" (illusionary)
- "The Enemy"
- "The Defector"
- "Tin Man"
- "Future Imperfect" (illusionary)
- "Data's Day"
- "The Mind's Eye"
- "Redemption II"
- "Unification II"
- "Face of the Enemy"
- "Birthright, Part II"
- "The Pegasus"
- ENT: "Future Tense" (database image)
The designation of "D'deridex-class" was first mentioned in "Tin Man", the designation as "B-type" was mentioned in "The Defector". The ship was also referred to as a "warbird class starship" by Picard in "The Defector".
The warbird that appeared in "Contagion" was referred to as a "battle cruiser", which seems to be an inaccurate classification for a vessel of this size. However, according to the script for that episode, the Romulan vessel was also referred to as a Bird-of-Prey. This indicates that the warbird model may not have been intended to be used in this case, and the battle cruiser reference was never changed to reflect the model used. It is also possible that the Romulan battle cruiser mentioned in TNG: "Angel One" may too have been the yet unseen D'deridex.
The D'deridex-class warbird was was the last new ship designed by Andrew Probert for the show, approved by the producers in March 1988. The studio model was made of cast resin and acrylic plastic. Built by Greg Jein the following month, it measured 36" × 25" × 10", and debuted in "The Neutral Zone" and was last seen in "By Inferno's Light".
The appearance of the D'deridex model has caused some confusion in regards to the color scheme. Well known publications shots showed the model both in a green-gray color scheme and a metallic blue-gray color scheme (to represent ships of the Tal Shiar, most notably in "The Die is Cast"). This was partly due, in the case of the first one, to "tweaking" the colors in post-production, but the other explanation for this was that the studio had two models made, the green one and best known first, and that they used them both. Co-built by model maker Bruce MacRae and almost identical, the blue-gray model differed from the green one in that it had an additional feature added on the outer sides of the warp engines and it debuted in "The Defector". The blue-gray model was the one that was included as part of the 40 Years of Star Trek: The Collection, estimated at $8,000 - $12,000, where it was sold at auction on October 7, 2006 for a winning bid of $30,000 ($36,000 including buyer's premium) . It was sold to the British collector who also acquired the USS Voyager and the USS Enterprise-C studio models.  In a run up to the auction, the model was on tour at the Creation Convention in Las Vegas from 17 August to 20 August 2006.
As of 2009 the green-gray model is still in the possession of Paramount Pictures.
The studio model of the Mazarite warship, from ENT: "Fallen Hero", was constructed from a D'deridex-class kitbash made by Dan Curry to be "sold" to the producers. The producers "bought" the design, and the prototype model was subsequently recreated in CG at Eden FX by Koji Kuramura and mapped by Robert Bonchune. This CGI model was later reused as the Illyrian starship seen in ENT: "Damage".
The following information of specifications and defenses comes exclusively from the Star Trek: Deep Space Nine Technical Manual:
- Production Base: Unknown; Romulan Star Empire
- Type: Heavy Cruiser
- Accommodation: 1,500 plus officers, crew, and troops
- Power Plant: One artificial singularity-drive warp core feeding two nacelles; two impulse system
- Dimensions: Length, 1,041.65 meters; beam, 772.43 meters; height, 285.47 meters
- Mass: 4,320,000 metric tonnes (est.)
- Performance: Warp 9.6 (observed)
- Armament: Six ship-mounted disruptors; two photon torpedo launchers
However, some of this information contradicts data from the original specifications of warbird designer Andrew Probert and also some observations of the D’deridex class in canon episodes.