In most spacecraft combat science fiction, the author takes concepts from historical and current wet-Navy warships and translates them into spacecraft. Even though this is highly unlikely to be the case. On the other hand, form follows function and some of the functionality of a wet navy might be general enough to still be true in interplanetary space.
For a much more in-depth analysis of the subject, I would direct you to Future War Stories entry on Military Spaceship Classes, Ships of the Line: Heavy Cruisers and Ships of the Line: The Battleship and Battlecruiser. For a more space-opera Sci-Fi analysis of space warships, see TV Tropes Standard Sci-Fi Fleet.
For a broad overview of some of the issues, study this penetrating analysis by the man known as Sikon
Mr. Andrew Jackson disagrees with Mr. Sikon's analysis.
Back to Sikon:
Rick Robinson had an observation:
Back to Sikon:
Again Mr. Jackson begs to differ:
Back to Sikon:
Isaac Kuo questions some assumptions:
As does Rick Robinson:
Back to Sikon:
Arthur Majoor had this cogent analysis of the origin of space warships.
Mr. Majoor's proposed future history is logical and self-consistent. However, as with all analysis of this type, it does rely upon a couple of assumptions. People who want to alter the history can tweak the assumptions.
Analogies can be drawn from history, though you have to be careful. Sometimes not all the constraints are the same. For instance, examining the Naval history from World War I to World War II and reasoning by analogy into interplanetary combat, one might come to the conclusion that space war will lead to the development of a one-man fighter. But there are different constraints that will probably prevent his.
Having said that, examining Naval history might be illuminating.
Before the 1860s, the Battleship was the queen of the ocean. It had titanic guns capable of blowing enemy ships out of the water, and armor thick enough to bounce off enemy shells. Granted it had all the speed and turning radius of a pregnant hippo, but that didn't matter.
Until some clown invented the Torpedo Boat. These little gnats could run rings around the battleships, were too agile to be targeted by the battleship's guns, and had torpedoes quite capable of sending the battleship to Davy Jone's Locker. Especially since the torpedo boats would attack in packs of twenty or more. The battleship was much too ponderous to avoid the swarm of torpedoes the pack would launch.
So the Destroyer was invented. This name was actually short for "Torpedo-boat Destroyer." This was a speedy, agile warship with quick guns designed to chew up torpedo boats. Of course this ability came at a price. The destroyer speed came at the cost of no armor, and the quick guns meant they are too light to damage anything heavier than a torpedo boat.
The upshot of this is that destroyers are pathetically vulnerable to enemy battleships.
So destroyers and battleships have to support each other. Destroyers protect their sister battleships from enemy torpedo boats, and battleships protect their sister destroyers from enemy battleships.
What happens if you design a warship that is equally balanced with regards to armor, guns, and speed? You get a Cruiser. Since cruisers are not specialized, they are viable enough to operate independently. They can be detached from a fleet as a task force of one for missions such as convoy raiding, deep scouting, and related missions. Generally a cruiser can outrun anything it cannot outfight. Heavy cruisers have large endurance for long distance scouting. Medium cruisers are often used as raiders, on convoys and other soft targets. Light cruisers generally operate with a fleet, scouting and repelling attack by enemy cruisers and destroyers.
And as an aside, it really annoys the Nifflheim out of me (and Jim Cambias agrees) when so many science fiction authors mistakenly use the term "Destroyer" for the largest class of warship. As you can see above, "Destroyers" are the weakest classes of warship, short of a torpedo boat. This mistake happens in the otherwise excellent TV show Babylon 5, the otherwise excellent novel MY ENEMY MY ALLY by Diane Duane, and the, er, ah, Star Wars movies. Mr. Cambias is of the opinion that this is due to the perception that the word "battleship" is old and corny and the term "destroyer" sounds really awesome.
Go to The Tough Guide to the Known Galaxy and read the entries "BATTLE CRUISER", "BATTLESHIP", "BATTLE STATION", "COMBAT SPACECRAFT", "DESTROYER", "FRIGATE" and "SPACE FIGHTERS".
For some of the difference between wet-navy ship classifications and possible space-navy classifications, refer to Mr. Ruppe's analysis above.
There is a trade off between armor, guns, and speed. Each comes at the expense of another. One method of displaying this is by a triangular graph. It has three scales for three variables. At any point on the graph, the percentages of each variable add up to 100%. There are areas of the graph. All points to the right of the red line have a higher percentage of weapons than of defenses. All points below the blue line have more weapons than propulsion. So the pointy bit that is below the blue line and to the right of the red line are all the points where the ship has more weapons than either propulsion or defenses.
This "weapon dominance" area is divided by the green line. All points above the green line have more propulsion than defense. So the blue area containing the letter "A" is the area where a ship will have more weapons than propulsion and more propulsion than defense. Indeed, in the adjacent purple area there are no defenses at all.
As an aside, Ken Burnside points out that there are actually five major dimensions of ship design: armor, guns, speed, endurance (how long between refueling and re provisioning), and command & control (how large the bridge crew is, which boils down to how many different tasks can be done simultaneously). He notes that if you just look at the first three variables, one would make the erroneous prediction that the battle of Jutland would have been an overwhelming advantage to the Germans task force. In reality, the British had the advantage because they built their ships with the endurance for long cruises and the Germans built their ships with an endurance of only two weeks.
This is the results of my playing around with allocating WWII ship classes on the grid. Be warned that the above classifications are totally my own invention, and are a gross simplification. Any actual Naval scholar will severely hurt themselves laughing upon viewing this. You are encouraged to make your own grid, incorporating the technological assumptions and limitations of your own SF universe.
Since making the above chart, it occurs to me that a ship ship with 50% weapons and 50% propulsion (currently marked as "missile") is a good description of an interceptor. "Long-range" interceptors are larger, have more endurance, but lower speed. "Short-range" interceptors have shorter range but a much quicker response time. Tthe area marked "courier" can also be "fast scoutships", faster than the other scouts because they are totally unarmed.
In reality, when mapping existing wet-navy ships onto the graph, there will be some holes. There are certain classes of ship that are theoretically possible to build, but in reality would have no well-defined function.
For instance, I used the term "packet" to mean an armed transport (because that is how the term was used in the old Triplanetary board game). They are in the dark orange and neon green sections. In the modern wet navy, there ain't no such class of ship.
CDR Beausabre says the only use he can think of for such a ship in a science-fictional setting would be some kind of raiding ship, i.e., some sort of vessel designed for planetary raiding as an independent mission - strong enough to punch through planetary defenses, land and hold a perimeter to awhile, and then escape. Which sounds like the Nemesis from the H. Beam Piper classic SPACE VIKING.
Marko Karonen points out that packets did exist, but you have to go back to the Age of Sail to find them. They only had cargo space enough for VIPs and mail, which was of critical importance before the invention of telegraphs and wireless radio. This would make sense in a science fiction universe which lacked faster-than-light radio. Age-of-Sail packets had some weapons to defend themselves against small enemy cruisers, and to make them too costly targets for pirates.
Actually, that is the main reason to make a chart like this, to find the interesting holes.
When Dimitri Mendeleev invented the periodic table of the elements, there were interesting holes in it. Mendeleev made the bold statement that these holes represented elements that had not been discovered yet, and predicted their approximate properties by analogy with the surrounding elements. He was vindicated when a couple new elements were discovered, and matched the predictions. So when you make your own ship chart, you may find holes. Examining the type of ship that would fill the hole will have you think either: [a] "What a worthless class of ship." or [b] "Wait a minute! That sort of ship could be useful." And some of the worthless holes might spark an idea later, say a specialized ship for a specialized mission, like the Brittania from Doc Smith's GALACTIC PATROL.
Note that the graph only classifies the ships by their relative proportion of the three components. It cannot distinguish between a mini-pocket battleship with six units of weapons, three units of armor, and one unit of propulsion and a cyclopean blot-out-the-sun battleship worthy of Darth Vader with 60,000 units of weapons, 30,000 units of armor, and 10,000 units of propulsion. Both will appear on the same spot on the graph. The light blue "A" section is labeled "torpedo boat" but some types of destroyers will fit in the same section. The difference is in the mass of the two ship types, which the graph doesn't handle.
It is better than nothing, but use it at your own risk.
In the current "wet" Navy, a "Fleet" is more of an organizational fiction rather than an actual entity. A group of ships belong to a fleet. But what is generally encountered at sea is a "Task Force." A few ships from a fleet are "detached" to form a task force charged with performing a specific mission. When the mission is completed, the ships of the task force are dissolved back into the fleet.
There are two classes of ships in a fleet: Main Units and Auxiliary Units.
Main units include Dreadnoughts (which were never an official type of unit but is included here as a tribute to E.E. "Doc" Smith, who spelled it "Dreadnaught"), Battleships, Battlecruisers, Heavy Cruisers, Light Cruisers, Escort Cruisers, Anti-aircraft ships, Destroyer Leaders, Destroyers, Submarines, Submarine Minelayers, Minelayers, Aircraft Carriers, and Aircraft.
Auxiliary units include Destroyer Tenders, Sub Tenders, Mine Sweepers, Aircraft Tenders, Fuel Ships (Oilers and Tankers), Supply (Logistics) Ships, Transports, Repair Ships, Hospital Ships, Colliers (missile supply ships), and Ammo ships.
There are ships that generally operate on their own, apart from any fleet. These are called Independent Units. They include Cruisers, Submarines, Gunboats, Torpedo Boats, Minelayers, Sub Chasers, Yachts, Aircraft, and assorted auxiliaries.
Don't sneer at the auxiliary units. An army marches on its stomach, and a rocket ship jets with its propellant tank. The old bromide is that amateurs study military tactics but professionals study logistics.
|US Navy Units|
|Task Element||Commander to Captain||One large vessel (plus escorts)|
|Task Unit||Rear admiral to Commodore||3 to 4 task elements.|
If no capital ships = FlotillaIf any capital ships = Squadron
|Task Group||Rear admiral||2 or more task units|
|Task Force or|
|Vice admiral||2 or more task groups|
|Fleet||Admiral||all vessels in a general region|
|Fleet admiral||Nation's entire naval forces.|
When translating wet navy concepts to deep space, "continents" or the "mainland" are Planets, "coastal" is Planetary Orbit, "islands" are Asteroids, and "the high seas" are Deep Space. Instead of a "coast guard" you would have an Orbit Guard. There was an old class of coastal defense ships called "Monitors", these would be Orbital Fortresses.
Of course ever since the writers of classic Star Trek took the movie The Enemy Below and re-wrote it into Balance of Terror, everybody knows that Submarines = Ships with a Cloaking Device. The advantage of submarines is that they are very good at hiding, and can attack while hid. In interplanetary terms, this would require a science fictional level of stealth, since by the laws of physics as currently understood interplanetary stealth is more or less impossible (see the entry "CLOAKING DEVICE" in The Tough Guide to the Known Galaxy). For a good treatment of this theme, read PASSAGE AT ARMS by Glen Cook. Early non-nuclear submarines needed sub tenders for logistical support. Nuclear submarines do not need them. Sub minelayers can lay mines without the large escorts that a surface minelayer requires.
Ken Burnside had this analysis:
There's a decent functional space to discuss here.
Most navies really have three sizes of ship.
- Small ships
- Medium sized ships
- Capital ships
Most navies have two roles that ships are designed for:
- Independent patrol
- Main battle fleet
Independent patrol sacrifices firepower (and sometimes protection) for cruise endurance and multi-mission capabilities.
Main battle fleet requires ships to be 'honed to the bone' - anything that doesn't make the ship more capabile in a fight is usualy a luxury.
History hasn't been kind to independent patrol capital ships. They're generally too expensive for the benefit they give the navy (something that eats independent cruisers for lunch and can do commerce raiding. Jackie Fisher's Battlecruisers in WWI and the German pocket battleships are two examples.
So this leaves:
- Frigate (Small ship, independent patrol)
- Destroyer (Small ship, main battle line)
- Cruiser (Medium ship, independent patrol)
- Armored Cruiser (Medium ship, battle line)
- Battlecruiser (Capital ship, independent patrol)
- Battleship (Capital ship, battle-line)
Within each role, you have specific missions, and you'll have different sizes of ships within each niche, depending on what specific navies did with their doctrines.
The frigate is the smallest thing that can be armed with guns capable of doing shore bombardment.
The destroyer may have less armament than a frigate; it's job is to shoot down threats to the bigger ships in the battle fleet.
The cruiser is a frigate that's generally got more armament, more armor, and more survivability. It usually has greater endurance.
The armored cruiser trades endurance for enough armor to maybe survive a hit from a capital ship's gun without being mission killed, and usually has the same number of guns as the cruiser with heavier throw weights.
The capital ship has Massive Firepower and the armor to stand up to it. Endurance is usually traded off somewhere.
Independent patrol Main battle fleet Small sized ships Frigate Destroyer Medium sized ships Cruiser Armored Cruiser Capital ships Battlecruiser Battleship
CDR Beausabre had this analysis. The topic is the design of the interstellar battlefleet for a fictitious race of aliens called the Loroi.
From The Napoleons of Eridanus (Les Grognards d'Éridan) by Pierre Barbet (1970). Decadent pacifist aliens from Epsilon Eridani are invaded. Desperate for military know-how, they kidnap a group of Napoleonic veterans fleeing Moscow in the winter of 1812. The head veteran uses Napoleonic analogies to handle alien military units.
Dean Ing has some interesting speculations on space warships. From "Vehicles for Future Wars", collected in DESTINIES vol. 1, no. 4, Aug-Sept '79, edited by James Baen.