Name prefixes
IRW: Imperial Romulan Warbird PWB: Praetorian Warbird (presumed) "IRW" may have been used occasionally, although I only remember the Khazara in TNG: "Face of the Enemy" being called "Imperial Romulan Warbird". The "PWB" prefix appeared on a casualties list in the Dominion War. Since none of the prefixes is very prominent, I'm not using them in this list.
The Bird-of-Prey was first sighted in 2266 when a starship of this type crossed the Neutral Zone and attacked the Earth Outposts. The ship was equipped with warp drive and armed with a powerful plasma energy weapon, and it had the ability to cloak. While cloaked, the Bird-of-Prey was not capable of firing but still warp-capable. Article: Warp Drive and Romulan History
Known ships
No name given
Annotations
The Romulan BoP was designed by Wah Chang and appears in TOS: "Balance of Terror" and in "The Deadly Years" too. Lt. Stiles states that Romulan ships have a big bird painted on their hull. Since his information comes from history books, rather than from secret intelligence reports, the BoP must continue a Romulan tradition in ship design.
The Romulan BoP was purposefully designed to fit a note in the supposed shooting script of TOS: "Balance of Terror": "The attacking vessel can now be seen definitely to be some modified version of a starship saucer main section..." In a deleted scene Commander Hansen of Earth Outpost 4 explicitly hints at the similarity of the design of the Romulan ship to that of Federation starships: "You see it, Enterprise?! Starship design. Warn Earth... espionage, stolen our designs... traitors..." More about the deleted scene at Star Trek History.
There is far more evidence supporting the existence of Romulan warp ships in 2266 and also in the Romulan War a century earlier than for the common notion that Romulans did not have FTL ships prior to their supposed alliance with the Klingons in 2268. Since Star Trek Enterprise this idea has been ultimately refuted. See Warp Drive and Romulan History. Even if the Romulan BoP in "Balance of Terror" were only capable of impulse speeds during the battle, this doesn't rule out that it has come from Romulus at warp. The identical ship is undeniably observable at warp speed in "The Deadly Years".
The name is obviously the only thing the Romulan BoP has in common with the Klingon BoP. In an early draft of "Star Trek III" Kruge steals his ship from the Romulans, but there is no mention that the Klingon BoP is actually a Romulan design too.
In the remastered versions of the two TOS episodes the top side of the Romulan BoP was shown from previously unseen angles and was given a hull grid and a more metallic looking surface than we may have expected. The underside with the bird depiction still looks like in TOS but now possesses a subtle hull grid too. The BoP also appears in TOS-R: "The Enterprise Incident", here replacing one of the previously three D7 battlecruisers.
A Bird-of-Prey from the 23rd century is still in service as of 2399. It is armed with disruptor cannons.
Known ships
No name given
Annotations
This ship, owned by a certain Kar Kantar, attacks La Sirena in orbit of Vashti on PIC: "Absolute Candor" and gets heavily damaged, losing its starboard nacelle pylon.
The design is essentially still the same as the one of the old BoP from TOS: "Balance of Terror"; the proportions are almost identical. The ship doesn't seem to have the plasma weapon any longer but is equipped with standard disruptor cannons. The most significant change is the addition of very pronounced hull panels (unlike the remastered version of TOS with its slight hull plating). Also, green Romulan-style lighting was added to the nacelles and countless small lights all over the hull, a bit like on the re-imagined D7 from season 2 of Discovery. Most of these lights can't possibly be windows, owing to the rather small size of the ship (unless the size was "re-imagined", which is an idea that I refuse to even consider). Overall, we might argue that the BoP from "Absolute Candor", except perhaps for the armament, is still the very same design as the one from "Balance of Terror". But in the spirit of visual continuity it makes more sense to classify it as an upgrade or a related, newer class, much like the Klingon K't'inga relates to the D7.
Eaglemoss gives the length of the upgraded BoP as 91.44 meters. But although it is not hammered in stone, I prefer to stick to the established length of the TOS BoP.
A Bird-of-Prey can be seen at the Fleet Museum in PIC: "The Bounty". Although this is arguably supposed to be a re-imagination of the "classic" design (also with regard to the appearance of the identical ship in SNW: "A Quality of Mercy"), it would make more sense if Starfleet got their hands on a later upgrade.
The Romulans possess D7 cruisers of Klingon design around 2268. The Romulan D7 is outfitted with a cloaking device.
Known ships
No name given
Annotations
The real-world reason for using the Klingon ship in TOS: "The Enterprise Incident" is that the Romulan BoP looked rather clumsy and little detailed. Ironically, before the episode the ship appeared only in one brief scene in TOS: "Elaan of Troyius" as a Klingon design, so it was not yet firmly established as a Klingon ship. Anyway, "The Enterprise Incident" clearly calls the Romulan ships a "Klingon design".
It is obvious that the specs are the same as of the Klingon D7 ships. The only change I made on the schematic is that I removed the Klingon emblem (although the actual models in the episode might have had it).
We don't know how exactly the Romulans got their hands on Klingon vessels. It is only speculation that the Romulans and Klingons had a brief alliance around 2268. The D7 ships could have been captured by the Romulans as well. While three ships could be seen in "The Enterprise Incident", we don't know how many ships the Romulans acquired altogether, how long they have been in use, or what kind of influence the technology transfer had on later ships. By the time of TNG, the Romulan and Klingon design lineages seem to have diverged again.
For TOS-R: "The Enterprise Incident" the D7s were given a Romulan bird pattern on the ventral hull. Also, one of them was replaced with a Bird-of-Prey.
The Warbird of the D'deridex class is a huge starship used by the Romulans in the 2360s and 2370s. The ship is twice as long as a Federation Galaxy class, with an advantage in fire power, but a lower maximum speed. The power source is an artificial quantum singularity. Article: Appearances of the Romulan Warbird Gallery: Romulan Starships
The D'deridex, designed by Andrew Probert, first showed up in TNG: "The Neutral Zone". On one occasion in TNG: "The Defector", the design class was called a "B-Type Warbird". Considering that this must be a Federation designation, while "D'deridex" is obviously Romulan, I assume they are equivalent names for the same class. "Warbird", on the other hand, may be a collective name for all big Romulan warships.
In TNG: "The Neutral Zone", it is stated that the ship is twice as long as a Galaxy class. The approximate length of 1200m is consistent through all reference manuals except for the unreliable DS9TM (here: 1041m), where several other ship lengths are off as well. Andrew Probert tells us that the actual design length is 1353m.
The Decius appeared as "Admiral Picard's" ship in an illusion created for Riker in TNG: "Future Imperfect". We may assume that a real ship name was taken from a database or Riker's memory, though.
The Belak and the Makar were mentioned as part of the fleet to attack the Founders' homeworld in DS9: "The Die is Cast". The fleet consisted of nothing but Cardassian Keldon-class and Romulan D'deridex-class ships as could be verified from various different angles. It seems unlikely that there are ships of other classes we haven't seen.
John Eaves designed the early BoP to appear in ENT: "Minefield" as a homage to the above TOS Bird-of-Prey. The Art Department originally included the typical bird painting on the underside that Romulan ships are supposed to have (TOS: "Balance of Terror"), but they were asked to remove it. The hull color is just as green as on 24th century Romulan ships (and on Klingon ships too). The rather modern looking nacelles were rounder in the first pass, as John Eaves tells us. They are similar to those on the Klingon Raptor class. A technology exchange?
It should be unmistakable now that Romulans were supposed to have warp drive ever since they encountered humans.
It is irritating to see that the ship already has cloaking, although this will be something surprising over 100 years later in "Balance of Terror". The plot of "Minefield" wouldn't have required cloaked ships at all.
Regarding the size of this vessel, Rob Bonchune's size chart has it at about 165m. However, since 130m would correspond much better with the structure of the 23rd century version, I will stick to this size.
The science ship appeared only in TNG: "The Next Phase" and is a redress of the Romulan scout (see below). The beak and tail sections were modified, while the center of the ship seems to have remained the same. This is why I assume that the center section, encompassing the warp engines, is actually the same size on the real ships. It may be a modular concept that can be adapted to different purposes. On the other hand, the whole ship was turned upside down, as the two ridges on the ventral and dorsal side indicate. The shorter ridge was on the top of the scout ship, but is at the bottom of the science ship. Moreover, the color was changed from intense green to a faint bluish green.
The particular science ship in TNG: "The Next Phase" had an experimental phase cloaking device. It is well possible that this was the only ship so equipped, and that after its failure (and the Federation knowing about it) the project was discontinued.
This ship consists of a central body and thin wing-like structures.
Known ships
No name given
Annotations
We can see these ships most prominently in "Remembrance" and briefly again in "Maps and Legends", "Nepenthe" and "Broken Pieces".
Ships of this type are visible aboard the Artifact in "Maps and Legends" and "Broken Pieces". Although it would seem useful to save space when landed, the wings are not hinged in a way that they could be folded up.
Ship type 1 was designed by John Eaves. It was labeled as a "warbird" on a storyboard (as seen in the Ready Room episode for "Absolute Candor"). The design was originally much bigger, and was meant to have carried the attack on Utopia Planitia, hence the preliminary designation as "bomber warbird" used by Eaglemoss, as well as the resemblance to the USAF B-2 Spirit.
This ship consists of a central body and extremely thin wing-like structures.
Known ships
No name given
Annotations
This ship type can be glimpsed in "Maps and Legends" and "Absolute Candor". It can be seen much more clearly in "Broken Pieces", now departing to destroy the Synth homeworld. The fleet that arrives at Coppelius in "Et in Arcadia Ego II" entirely consists of type 2, with the exception of Oh's Warbird.
Of all increasingly flimsy ship designs of the past 20 years, this is most extreme example, more like a paper plane than like something that looks spaceworthy. It looks much like a jet aircraft and the CGI may have started as one, considering the recognizable "canopy", "intakes", "canards" and "vertical stabilizers".
Unlike other Romulan vessels that are traditionally green and similar as the Snakehead, these ships are gray, which may indicate they are not operated by the regular Romulan forces (of the Romulan Free State) but by the Zhat Vash/Tal Shiar. Yet, we don't know the exact affiliation of the other Romulan ships of the series either. Type 2 also has a bird-of-prey depiction on the underside, just like the classic Romulan ship of that name.
One ship of the class appears in Raffi's search results for "Red Lady" in PIC: "The Next Generation", which may mean this is the (translated) name of the ship.
Class specifications
Length: 118.87m
The Artifact
General description
This Borg cube was seized by the Romulans in the early 2380s and remained in their possession until 2399.
The Valdore is a large Romulan ship type of the late 2370s. The class name is unknown. Gallery: Romulan Starships
Known ships
Valdore
Annotations
The Valdore type is the design of two Romulan Warbirds in the Bassen Rift in "Star Trek: Nemesis", of which the one commanded by Commander Donatra was verbally identified as "Valdore". John Eaves may have the laid out the ship intentionally to resemble the Klingon Bird-of-Prey, considering that the BoP was originally meant to be a Romulan ship. But it makes no sense at all in retrospect now that we know that the Klingon BoP is in reality a genuinely Klingon design (ENT: "The Expanse").
The size figure comes from the movie's ship scale sheet.
While the Valdore herself is green like other Romulan ships too, the sister ship in "Nemesis" was given a brown hull. The possible reason was to allow a differentiation of the two vessels of which presumably only the Valdore survived, albeit with very bad damage. Maybe the two ships belong to different production batches or to different branches of the Romulan military. Yet, we may decide to disregard the subtle color divergence which may be partly due to light scattering in the nebula.
This is a capital Romulan ship of the late 24th century.
Known ships
No name given
Annotations
Just one Warbird, Oh's flagship, appears among the countless type 2 ships in the fleet of "Et in Arcadia Ego II".
Originally, "Warbird" was a name for the Romulan capital ships, such as the D'deridex class that first appeared in TNG: "The Neutral Zone". In more recent years, however, Trek writers and producers customarily use "warbird" as an umbrella term for any Romulan (and even Klingon!) ships. Of all Romulan vessels of Picard that were casually labeled as "warbirds", this one is the only one deserving of this name.
Class specifications
None available
Shuttles & Probes
Beacon
General description
Numerous beacons are placed around the Artifact.
Known beacons
No name given
Annotations
We can see the beacons in all episodes in which the Artifact is still stationary, most clearly in a close-up in "The Impossible Box".
It is unknown whether the beacon just serves as a demarcation or whether it would be capable of attacking incoming enemy vessels.
The Romulan drone is an unmanned vessel that is remote-controlled using a telepresence unit. For that purpose it is equipped with an array of subspace transceivers in the form of many spikes. The pilot using the RC interface must be a telepath. A holographic skin may be applied to the drone to mimic the appearance of any other vessel, leaving only the Romulan power signature as a clue of its true identity. The drone is armed with beam weapons, extremely maneuverable in combat and capable of self-repair. It can reach speeds in excess of Warp 5.
Known ships
No name given
Annotations
In the Andorian trilogy beginning with ENT: "Babel One" the vessel was called a "marauder" by Starfleet, whereas the Romulans referred to it as "drone". Two of them were encountered, and both were destroyed at the end of "The Aenar". The drone is a very small ship. Although Trip and Malcolm spend some time exploring its interior, it must be less than 40m long compared to other vessels and particularly to Enterprise. In this respect it is ridiculous that the drone is meant to be a "modified Warbird" as stated in the episode.
The CG model is a modification of the "Flea ship" from VOY: "The Fight": Considering that the model has likely been considerably refined for close shots, we need to wonder why no new ship was built to portray such a prominent vessel of a major race.
Class specifications
Length: approx. 35m Max. speed: Warp 5
Mine
General description
In the 22nd century the Romulans deployed cloaked mines like this one to secure planets claimed by their empire. They were equipped with a sophisticated anti-tampering mechanism.
Known ships
No name given
Annotations
The mines appeared in ENT: "Minefield". They were equipped with a cloaking device but could be made visible using Daniels's equipment that already served to penetrate the Suliban cloaking in "Shockwave". It was not entirely clear in the episode whether the Romulans themselves built the minefield. Yet, bearing in mind that the cloaking of their vessels (see above entry) was even more advanced, it is very likely that the mines belonged to them.
The Romulan shuttle has about the size of a Federation runabout. Like all known Romulan ships, it possesses a cloaking device.
Known shuttles
No name given
Annotations
The shuttle only appeared in DS9: "In the Pale Moonlight".
Class specifications
Length: 24m
Shuttles on Romulus, visible in "Star Trek Nemesis"
Most of these shuttles are not clearly identifiable. Shuttle #1 seems to be a re-use of the Qomar ship 4. In the same picture we can see two shuttles, #2a and #2b, that are obviously identical and that could be Devore shuttles. Shuttle #3 looks like another shuttle of this type.
The Snakehead is a shuttle-sized, single-seated vessel with enormous engine power and firepower for its small size.
Known shuttles
No name given
Annotations
Narek follows La Sirena in a Snakehead in PIC: "Nepenthe". We can also see these small ships in the battle against the orchids in PIC: "Et in Arcadia Ego II". Snakeheads were previously not visible in the fleet, so they were likely deployed from the larger vessels.
Class specifications
Length: 8.36m
Workbee
General description
The Romulan workbee is a small, boxy utility craft.
Known shuttles
No name given
Annotations
We can see Romulan workbees in PIC: "Remembrance", "Maps and Legends" and "Nepenthe".
Class specifications
None available
Reman Vessels
Reman ships, as they appear in "Star Trek Nemesis", obviously have a design lineage very different from usual Romulan ships. There is no satisfactory explanation in the movie.
The Scimitar is a huge vessel built by the Reman rebels on a secret base. Apparently superior to any ship of either the Federation or the Romulans with 52 disruptors and 27 torpedo banks, the Scimitar is capable of firing while cloaked. It is also equipped with a thalaron emitter, a weapon that destroys any organic tissue. The thalaron emitter is activated by unfolding the wings of the vessel. There is at least one large shuttlebay with dozens of Scorpion-class fighters. Gallery: Romulan Starships
Known ships
Scimitar
Annotations
The Scimitar appears as Shinzon's ship in "Star Trek: Nemesis" and is called a "Reman Warbird". It was designed by John Eaves. The irregular shapes are borrowed from the Breen ship and the Son'a vessels and the overall structure resembles the Jem'Hadar battleship. Together with its countless aggressive spikes and moving parts, this is an overall uninteresting and unsound design in my view.
The size figure comes from the movie's ship scale sheet (see the Valdore above).
The Reman Scorpion fighter is a small craft with two seats. It is equipped with a disruptor cannon.
Known shuttles
No name given
Annotations
The fighter appears in "Star Trek Nemesis" and seems to be a design previously unknown to the Federation. As Data finds the name in the databank of the Scimitar, the impression is created that "Scorpion" is the official class name, rather than a (human) nickname of the design - unless he swiftly translated the name of a Romulan animal resembling a scorpion.
Class specifications
Fighter Length: approx. 7m
Unknown Romulan Class
Pi, scout ship, crashed on Galorndon Core in TNG: "The Enemy"
We may assume that it is of the same class as the scout that appeared in TNG: "The Defector", but this is only speculation.
D'ridthau, Romulan flagship, mentioned destroyed in DS9: "What You Leave Behind"
This could be easily yet another D'deridex or a ship of the Valdore type.
PWB Koderex, Romulan vessel on the casualties list of the Dominion War in DS9: "Image in the Sand" and "The Siege of AR-558"
Gasko, Romulan vessel that located the Rio Grande flying without pilot in DS9: "Paradise"
Shaenor, Ship operated by the Zhat Vash that was assimilated by the Borg cube in the early 2380s, which led to a submatrix collapse and allowed the Romulan to take possession of the "Artifact" (PIC: "The End is the Beginning")
Talvath, science (spy?) vessel, commanded by Telek R'mor in 2351 (VOY: "Eye of the Needle")
We may assume that it is of the same class as the science ship that appeared in TNG: "The Next Phase", but this is only speculation.
PWB Tomal, Romulan vessel on the casualties list of the Dominion War in DS9: "Image in the Sand" and "The Siege of AR-558"
In the remastered versions of the two TOS episodes the top side of the Romulan BoP was shown from previously unseen angles and was given a hull grid and a more metallic looking surface than we may have expected. The underside with the bird depiction still looks like in TOS but now possesses a subtle hull grid too. The BoP also appears in TOS-R: "The Enterprise Incident", here replacing one of the previously three D7 battlecruisers.
The Bird-of-Prey appears as an 
The scout ship was designed by Rick Sternbach and only appeared in TNG: "The Defector". It was later modified to become the science ship (see above).
See Borg Ships, cube variant 3
The mines appeared in ENT: "Minefield". They were equipped with a cloaking device but could be made visible using Daniels's equipment that already served to penetrate the Suliban cloaking in "Shockwave". It was not entirely clear in the episode whether the Romulans themselves built the minefield. Yet, bearing in mind that the cloaking of their vessels (see above entry) was even more advanced, it is very likely that the mines belonged to them.
The shuttle only appeared in DS9: "In the Pale Moonlight".
Narek follows La Sirena in a Snakehead in PIC: "Nepenthe". We can also see these small ships in the battle against the orchids in PIC: "Et in Arcadia Ego II". Snakeheads were previously not visible in the fleet, so they were likely deployed from the larger vessels.
We can see Romulan workbees in PIC: "Remembrance", "Maps and Legends" and "Nepenthe".
The fighter appears in "Star Trek Nemesis" and seems to be a design previously unknown to the Federation. As Data finds the name in the databank of the Scimitar, the impression is created that "Scorpion" is the official class name, rather than a (human) nickname of the design - unless he swiftly translated the name of a Romulan animal resembling a scorpion.
