Sorry if this question was already asked, but even if we accept that a D'deridex-class warbird was 1,041 meters long, it still has several times the internal space of a Galaxy-class starship, itself having 35% unused internal space that can be used for mission-specific equipment.

Yet, by DS9: "The Die is Cast", the Romulan warbird's crew quarters looked spartan by Federation standards and they had ~1,500 crewmen onboard. This begs the question: What was all that internal space used for?

  • 2
    Keep in mind two things - 1) the large middle section of the ship was open, and 2) unlike the Federation, Romulan vessels maintained large hangars & holds full of smaller craft (shuttles, fighters). – Omegacron May 6 '15 at 15:19
  • 1
    I understand that the artificial singularity is responsible for the large open section in the middle but the beak section alone still had ~3-4 times the internal habitable volume of a Galaxy-class ship. Perhaps the aft portion of the ship served as a large hangar and as a large cargo hold though. – NSERC Protester May 6 '15 at 15:35

We know the D'deridex was intended to be larger, and was occasionally photographed as being larger, but this isn't all that clear-cut. There is quite a bit of empty space around the singularity core part of the ship and while the corridors appear longer, the mass difference between the two ships isn't much greater.

Given that this is a television show and not a physics or volumetrics study, The nature of starships from different species could be a product of varying technologies, size vs technological capacity and modernization techniques allowing for each species to design their ships differently but still have them share similar fighting capacities.

  • The Galaxy Class and the D'deridex were considered to be comparable in fighting capacity and overall awesomeness with the nod going to the Romulans for the cloaking device and to the Federation for creating a more durable ship overall.

  • While the Romulan ship is clearly much larger, its carrying capacity while it is surely greater, may not support more staff due to other limitations we are not aware of such as life support capacity. The ship may be larger but may not support more people than a comparable Federation ship.

  • We are also not aware of what technology the Romulans use to create their ships. The D'deridex may be larger but overall not far tougher than the Galaxy class, despite the volume. No references I researched indicated if the space onboard was being used for anything in particular, such as marine barracks, extra cargo space, or crew areas for larger disruptor technology arrays.

Galaxy class starship:

  • Length - 642.51 meters

  • Beam - 463.73 meters

  • Height - 195.26 meters

  • Mass - 4.5 million metric tons

D'deridex class starship:

  • Length - 1,041.65 meters

  • Beam - 772.43 meters

  • Height - 285.47 meters

  • Mass - 4.3 million metric tons

enter image description here

  • The D'deridex class Warbird may have been longer, wider, and taller than the Galaxy class but it was not more massive making the presumption of greater size more likely an illusion of volume due to the empty space in the center of the ship design.

enter image description here

  • Andrew Probert, who designed the D'deridex-class Warbird, intended for it to have a length of 4,440 feet (1,353 meters). He writes, "The wings were to have had a LOT more substance to them (as seen in my drawing) but was reduced [on] the model. They are separated to allow the engines to 'see' each other and generate a warp field. As previously noted on the board, I did not design the subsequent ships that ignore my attempt at requirements-for-warp-drive continuity."
| improve this answer | |

In Star Trek canon episodes dating back as far as TOS (ex.: The Enterprise Incident) and early TNG, there is an allusion made that Romulan technology in a lot of areas that are not directly tied to weapons and cloaking capability is somewhat more primitive than Federation technology. More advanced technology almost always yields a net reduction in volume for a given component.

Unfortunately, we're never told if the Romulans purchased the Klingon D7 Battlecruiser hulls from the Klingons, or if they were manufactured by the Romulans under contract, or if they were a blatant rip-off of what they saw as an excellent design for a combat vessel (similar to the way the Russians ripped-off of the design of the B-29 Superfortress). However, it almost doesn't matter because the mere appearance of those hulls in the Romulan historical inventory strongly suggests that the Romulans found their non-combat ship systems to be vastly inferior to those of their Federation counterparts. Considering the Federation's focus on broad ranging scientific advances in all aspects of starship engineering, it is highly unlikely that even if the Romulans were engaged in wholesale theft of federation technology that they would be able to maintain technical parity in engineering systems deployed in contemporary vessels.

If I had to guess, I would say that not only does the Federation typically deploy the most advanced propulsion systems (routinely outrunning or outmaneuvering same-class Romulan vessels), it probably also deploys the most advanced structural integrity fields and inertial damping systems to go along with it.

Matter Antimatter Annihilation (MAA) vs Singularity:

MAA amounts to storing incredibly dense potential energy in a fuel form where the fuel is produced elsewhere (ex.: a starbase), or is produced by the ship's own fusion reactors when not running at warp speeds. This is similar to the way a hybrid car powers the drive system from batteries that are constantly being replenished by an internal combustion engine.

Conversely, using a singularity is more like harvesting energy from a natural source that is difficult to initiate, control, and even shut down. Although it's a bunch of speculative technology, the analogs in current energy capture technology indicate that a harvesting approach almost always requires larger volume, low density systems, whereas a fuel based approach can be extremely energetic in a small, high density volume.

If the analogs in fuel generated energy vs direct harvesting of energy from a natural phenomenon holds for the Romulan singularity power source, that alone could explain why the D'deridex is so much larger. A good portion of it's internal volume may be devoted to initiating (no small feat that), manipulating (again, probably harder to do than with an MAA approach), and subsequently harvesting energy from a singularity. It could be that those volumes are needed to achieve similar performance to that of a much more compact and considerably less complex Federation MAA system.

Energized structures:

Klingons and Romulans focus heavily on offensive, defensive, and maneuvering systems. In those areas they tend to excel, which is to be expected of races that perceive their warrior castes to be the foundation of their civilizations. In these areas, it is to be expected that their technology would match or slightly exceed the performance of their Federation counterparts.

Romulan ships, in particular, seem more dependent on physical structures within the ship to maintain structural integrity instead of using energized structures like Federation ships. Their vessels seem to all make use of either broadly distributed structures with opposing structures to balance them, and relying on considerably more bulky structures for smaller scales.

If the observation holds true, this fact alone would dramatically increase internal volume of virtually any Romulan vessel, even if the mass was close to the same as a comparable Federation vessel. This is due to the fact that wider spaced spars in any non-energized or low-tech lightly energized structure will have better moments of inertia and sheer resistance than trying to bulk up and strengthen a tighter, closed, non-energized or low-tech lightly energized structure. You could almost use the differences in the design approaches between a deep sea submersible (Federation energized structures) and a suspension bridge (Romulan non-energized or low-tech, lightly energized structures) as an illustrative metaphor. It may even been that having to rely on a larger, less dense structure is what made it practical for the Romulans to employ a singularity in the first place.

Also, it might be impractical to maintain intertial damping fields over the larger volumes this implies, which might mean that large portions of the internal volume of a D'deridex may not habitable while the ship is maneuvering inside a warp field, which would explain why the large volume does not correspond to a proportionally larger crew complement or evacuation capacity.


Lastly, Federation weapon systems seem to have always been more compact than those of their counterparts. Comparisons between photon torpedo tube bays between the Klingons and Federation make that very evident. The large size of Klingon disruptors in comparison to Federation Phasers (From hand held all the way up to bird of prey deployment) is very evident. Romulan plasma weapons have also been alluded to as taking up a great deal of internal volume, possibly making use of large numbers of low-density, high-energy, capacitor-like modules.


Taking all of this into account, it is a lot easier to see why a D'deridex might need to have so much more internal volume compared to a Galaxy in order to achieve comparable performance.

| improve this answer | |

Of course there is the real answer, Sci-Fi Writers Have No Sense of Scale. But let's ignore that ...

  • The DSN Technical Manual tells us about a "1500 plus" complement. How large is that plus in an emergency?
  • The mass of 4.32 megatons is close to the Galaxy class, which has 1,012 officers and crew and a maximum capacity of 15,000 (or possibly 16,012 ...). If we take 1,500 and 1,000 for the D'Deridex and the Galaxy, it follows that the Romulan quarters would be slightly more lightweight than the Federation quarters. Less weight generally means less volume.
  • Assuming the same kind of evacuation capacity, the Warbird might have room for 22,500 people in an emergency.

Last but not least, consider that technology is not uniform across the Star Trek universe. Perhaps their warp engines are lightweight but bulky. Or their life support isn't quite up to Federation standards.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.