Types of Iain M. Banks' Culture warships

Question

I've read a few of Iain M. Banks' Culture books and I'm intrigued by the types of Culture warships.

I know there are massive General Purpose Vessels and Special Circumstance Vessels but there's another category – Culture warships.

Mr Banks avoided the usual trope of Destroyers, Cruisers, Battleships etc.... Instead I've seen Thug type, Hooligan type and Roughneck type. (Probably others but I don't think I've read all his books.) Is there mention anywhere of which warship type is more powerful?

I.e. Is a Thug equivalent to a Destroyer and a Hooligan equivalent to a Cruiser? Or possibly the other way round? Or is a Roughneck the biggest fighting vessel?

Answer 1

Basically the newest ship is the most powerful. In Consider Phlebas the Killer-class ships Trade Surplus and Revisionist are typed as Rapid Offensive Units (used for front-line units), but when we find a Killer-class ship later in the series, the Attitude Adjuster in Excession, it's been demoted to a Limited Offensive Unit.

At the same time, in Excession, the Gangster-class Heavy Messing is now what is consider a ROU; from a bit of description of the baroqued ROUs stored in Pittance we find an approximate size:

The sixty-four ships stored in this hall were Gangster Class Rapid Offensive Units; slim segmented cylinders over two hundred metres tall and fifty in diameter.

(Note that the Affronter heavy cruisers are much larger; a couple of kilometres long, but they are at a comparatively lower tech level, and also have crews.)

But based on the AI-commanded warships built by Sleeper Service, even the Gangsters are being replaced (note that the highest-quality ships are built in the fewest numbers):

• Type One Offensive Units (roughly equivalent to Abominator class prototype): 512.
• Type Two Offensive Units (equivalent to Torturer class): 2048.
• Type Three Offensive Units (equivalent to Inquisitor class prototype, upgraded): 2048.
• Type Four Offensive Units (roughly equivalent to velocity-improved Killer class): 12 288.
• Type Five Offensive Units (based on Thug class upgrade design study): 24 576.
• Type Six Offensive Units (based on militarised Scree class LCU, various types): 49 152.

At this point the Killers are now barely better than a Limited Contact Unit.

Then we meet a full Abominator, the Falling Outside the Normal Moral Constraints in Surface Detail where the single ship takes out an entire squadron of GFCF ships in a fraction of a second. A squadron that would be capable of a one-shot kill of a Torturer class. (In Surface Detail we also see that the Psychopath class has been downgraded to Fast Picket from Very Fast Picket in Excession.)

It's also worth noting that Culture warships have a recognizable size/profile:

The three craft were unambiguously warships; slightly longer and fatter than the Grey Area itself but tapering at either end to points surmounted with large spheres. Spheres which could logically only contain weaponry. Quite a lot of weaponry, judging by the size of the globes.

(The quote refers to 3 of the T3OUs fabricated by Sleeper Service.)

So it's safe to say that Culture warships are approximately cylindrical, two to three hundred metres long and about a third to a fifth as wide. The specific shape varies (IIRC Torturer class were a single tapered section at the end of a longer cylinder) but they are all basically the same size. The difference between classes is that the newest class is the most powerful.

Answer 2

The Culture mostly uses the term Unit for ships, but occasionally others. The big ships are General Systems Vehicles (GSV) or occasionally Medium Systems Vehicles (MSV) and Limited Systems Vehicles (LSV). A GSV is supposed to contain every cultural and technological achievement of the Culture. Smaller ships are called Unit, e.g. the General Contact Unit (GCU) or Limited Contact Unit (LCU), the scout craft used by Contact.

Through much of the series, warship are called Offensive Unit, e.g. General Offensive Unit (GOU), Limited Offensive Unit (LOU), or Rapid Offensive Unit (ROU). Within those units there are class names, like Thug, Murderer, or Hooligan.

• Consider the Headcrash, a Delinquent-Class General Offensive Unit from The Hydrogen Sonata. Headcrash is the individual ship name, Delinquent is the specific class, and GOU is the category.
• Compare the real-world USS Michael Monsoor, a Zumwalt-class Guided-Missile Destroyer. Michael Monsoor is the individual ship name, Zumwalt is the specific class, DDG is the category.

Banks being Banks and the Culture being the Culture, they are very uneasy with the concept of having a military, but came around after the Iridian War. So lying to themselves and to others, later on the Delinquent-class GOU became a Fast Picket (FP) and the Gangster-class ROU became a Very Fast Picket (VFP) when the biggest weapons were removed. There was still plenty of firepower from secondary weapons. At thimes, (Demilitarized) Offensive Unit was used for Fast Picket, e.g. (D)GOU or (D)ROU. As of Surface Detail, new GOU were listed as Picket Ships, another deliberate misdirection.

Your question is somewhat difficult to answer because of the shift in warship designations in the real word. A modern destroyer has about the same displacement as a WWII heavy cruiser. It seems clear that, at any time, the LOU is smaller than the contemporary GOU and the ROU is faster than a LOU. It is unclear if a ROU is also faster than a GOU, since bigger ships tend to be faster in that setting. But over the centuries, they are all getting faster, so it would be unfair to compare a The Player of Games-era GOU with a Surface Detail-era GOU ...