In the section Ship Design Analysis we will examine what spacecraft warships will need, what they won't need, and what sort of tasks they will likely be required to perform. In the section Ship Types we will examine the thorny issue of the terminiology of the various types of spacecraft.
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.
|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.|
The brain trust that I
copy from research for spacecraft combat material have developed their own private jargon. As a public service I present a small glossary so you decipher what they are talking about.
Also called a "Space Control Ship". Basically a mobile control center for combat drones.
It is a lightly-armed combat spacecraft carrying an enormous C4I electronics suite (communications/command/control/computers/intelligence) tasked with controlling huge numbers of remote-controlled space combat drones armed to their cute little pointy teeth. Sort of like the brain center inside a huge swarm of deadly metal space-going hornets with nuclear stingers.
The idea is that the control ship and its human crew stands off at a (hopefully) safe distance from the battle, and sending in hordes of expendable drones to savage the enemy ships.
Please note that the control ship probably will NOT carry and service the drones, since the control ship will have to be nimble enough beat a hasty retreat if the battle goes terribly wrong. The drones will be carried by separate parasite-carrier spacecraft. The control ship might contain the only live human beings in the entire swarm.
A combat spacecraft or weapons platform with a hypervelocity kinetic energy weapon as its primary weapon. Since the acceleration of the projectile increases with the length of the weapon barrel, these tend to be in spinal mounts. Requires large amounts of electricity (advantage: missiles), but the projectile is a simple inert lump of matter (disadvantage: missiles).
It is such a good defense it could render torch missiles to be totally worthless.
A Lancer is a small fighter-type combat spacecraft armed with kinetic energy weapons and/or missiles where most of the weapon kinetic energy is supplied by the spacecraft's engines.
Example: imagine a fighter accelerating to 3 kilometers per second on collision course with a Blortch Empire space battlecruiser, lightly ejecting a few penetrator shells, then frantically trying to change its vector so it doesn't crash into the battlecruiser. The inert penetrator shells will continue on collision course, tearing through the battlecruiser at 3 km/s relative doing damage as if they were packed to the gills with TNT.
Generally this is a preposterous waste of your combat dollar, unless there are special circumstances. Right off the bat the Lancer spacecraft will need at least four times the delta-V of an equivalent missile, since unlike the missile the Lancer is not on a suicide mission. A missile just has to do one burn to the target. The lancer has to burn for the target, do a counter-burn to stop, do a burn for home, and do a counter-burn to stop at home.
Military strategy theory that basically says whichever side has more combat units in the battle automatically wins. Science fiction authors and game designers find this to result in scenarios that are drearily boring, so they often go out of their way to try to figure out extenuating circumstances to ensure military combat in their novels is non-Lanchesterian.
According to Rick Robinson, a "laserstar" is a combat spacecraft with a laser cannon as its primary weapon. Requires large amounts of electricity (advantage: missiles), but since it does not launch a projectile it theoretically has an infinite number of shots (disadvantage: missiles).
Occasionally the term is used for an impressively armed combat spacecraft suitable for political use in gunboat diplomacy.
A conventional missile is a rocket with a warhead for a payload and murder in its heart. This poor term is used in a variety of conflicting ways in this website. Though all of definitions refer to something that is self-propelled, as opposed to railgun shells and other gun-launched kinetic energy weapons.
Since it is self-propelled, it does not require large amounts of electricity (disadvantage: laserstars and kinetistars). But each missile is an expensive precision crafted device containing its own fuel (advantage: laserstars and kinetistars).
In standard military parlance, a "missile" is guided while a "rocket" is unguided. Rick Robinson suggests that a "torpedo" is a missile with acceleration less than a spacecraft while a "missile" is a missile with acceleration greater than a spacecraft (the same way a wet-navy battleship can dodge a sea-going torpedo but not a guided missile). In GURPS: Transhuman Space they refer to a missile with acceleration less than a spacecraft as an "Autonomous Kill Vehicle" (AKV).
Sometimes spelled "mother ship" or "mother-ship".
The classic example is the Battlestar Galactica, a space-going fighter-aircraft carrier. But science fiction has examples of huge battleships containing a few destroyer-sized ships. For example in The Expanse, the battleship Donnager carries several Corvette Class ships like the Tachi / Rocinante.
A small spacecraft carried internally or in surface blisters on a larger spacecraft. The classic example is parasite fighters housed inside a fighter-carrier, e.g., a Viper launched from the Battlestar Galactica. But science fiction has examples of parasite craft such as ship's boats, captain's yachts, cutters, and landing shuttles. And the Death Star carried entire Star Destroyers.
The carrier can commonly recover and service the parasites, but not always.
A spinal mount is when instead of mounting a weapon on a warship, you start with a titanic weapon and build the warship around it. Essentially the weapon becomes the backbone or spine of the warship.
The advantage is the ship has the biggest possible
phallic symbol weapon. Disadvantages include the difficulty supplying the monster with power, the ship savagely recoiling backward when you fire it, and having to turn the entire ship in order to aim it.
A tender is a small vehicle that services other larger vehicles. Basically a cut-rate mothership that deals with larger rather than smaller ships. Obviously a tender cannot carry larger ships internally (unless it is a TARDIS).
Conventional missiles come equipped with propulsion that is high acceleration but short duration (e.g., a few seconds). They sprint to their target, but do not have the endurance for a prolonged chase.
Torch missiles, on the other hand, are equipped with propulsion giving them acceleration and delta-V comparable to the target spacecraft they are trying to kill. Which means if you do not kill the missile first, it will chase you all over entire the solar system. For years. And it will eventually catch you because it is on a suicide mission and you are not.
The drawback is such a missile will be almost as expensive as their prey, and an order of magnitude or two more expensive than a conventional missile. It also has no special immunity from the target's point-defense.
If your point-defense is ineffectual against an enemy torch missile chasing you, the expensive solution is to target it with a friendly torch missile of your own. As with most things, allowing your warships to carry large numbers of torch missiles has unintended consequences.
The dirt-cheap solution is to kill the enemy torch missile with hordes of inexpensive Kirklin Mines. Since a spacecraft can carry a gazillion Kirklins for the price of one torch missile, this strategy could very well make torch missiles an utter waste of good military expenditure.
Byron Coffey has a penetrating analysis of warship type by theater of operation and role.
For a broad overview of some of the issues, study this penetrating analysis by the man known as Sikon
Mr. Anthony 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:
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 ternary plot (aka ternary graph, triangle plot, simplex plot, de Finetti diagram).
It has three scales for three variables. For space warships, we will use the percentage of the ship's mass devoted to Propulsion (speed), Weapons (guns), and Defense (armor).
At any point on the graph, the percentages of each variable add up to 100% (representing 100% of the ship's total mass). For example, point A is 50% weapons, 20% defense, and 30% propulsion. 20% + 50% + 30% = 100%
There are specific regions on the graph:
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.
The tabletop boardgame game Godsfire was created by Lynn Willis. For purposes of the game he wanted three different combat unit designs, each one hyper-optimized for one particular strategic doctrine. Examining the resulting unit designs is instructive.
There are three types of combat units
Here are the in-depth details on the difference between the combat unit types. If you could care less then skip to the next section.
The strategic map is a 3D map of space. Each location is called a "cell." Certain cells contain inhabited solar systems, these are called "system cells." Those cells represent the solar system and orbital space over the inhabited planet.
For every planet in the game there is a specific planet map. The planet in question is divided into four regions (quadrants). This represents the ground surface of a planet.
So combat units in space will occupy cells on the strategic map, combat units orbiting a planet will occupy the corresponding system cell on the strategic map, and combat units on the ground (or in the aerospace zone) of a planet will be on the corresponding planet map.
Units have a "combat strength." This is a measure of relative strength and is used with a die roll to determine who hurts who in any combat situation. Meaning whichever side of the combat has the highest total combat strength also has the better odds.
The advantage of a SQD is a group of two or three units is stronger than the sum of their parts. A 1 SQD has a strength of 1, a 2 SQD has a strength of 3 (not 2), and a 3 SQD has a strength of 5 (not 3). The disadvantage of a SQD is it cannot occupy a region on a planet (it cannot land), and it cannot attack hostile units on a planet unless the SQDs are assisted by an equal number of friendly AGs or PDFs also on the planet.
The advantage of a PDF on a planet map is it can attack hostile units [a] in the same region, [b] in the corresponding system cell (hostiles in orbit), and [c] hostile units on the strategic map within two cells of the system cell (SQD and AG can only attack hostile units within one cell, adjacent). In addition during an attack a PDF cannot be harmed unless at least half the hostiles are also on the ground (a purely spaceborne attack cannot hurt a dug-in PDF, you have to go in after them). The disadvantage of a PDF is that if it is in space its combat value is Zero (because they are in the belly of unarmed cargo transports, remember?). They are automatically destroyed by attacks by hostile SQDs and/or AGs, unless escorted by friendly SQDs and/or AGs. PDFs in space cannot land on a planet unless both the corresponding system cell and planet map region is free of hostile units.
The advantage of a AG is while its combat strength in space is 1, it is 2 while occupying any system cell or planet region. Unlike PDFs, an AG can land in a planet region that contains hostile units. On a planet an AG can move from one planet region to any other region, a PDF can only move to an adjacent region. The disadvantage of an AG is mainly it does not have the major advantages of the SQD and PDFs: [a] a group is not stronger than the sum of its parts like SQDs, [b] on the ground it can only attack hostiles in same region or in system cell, it cannot attack hostiles withing two cells like the PDFs, [c] it is harmed by a purely spaceborne attack.
The joker in the deck is that while playing the game, a player does not have a free hand to produce whatever types of units they desire. Politics rears its ugly head.
Each planet is divided into four regions. Each region has an Economic Level: Subsistence, Agriculture 1, Agriculture 2, Industrial 1, and Industrial 2. Each region is controlled by one of three political parties: the Extremists, the Reactionaries, and the Moderates. As with most games of this type only regions with an economic level of Industrial 1 or Industrial 2 can produce more SQDs, PDFs, and/or AGs. No surprises there. Warships and army hardware are produced at factories, not at farm lands, makes perfect sense.
The part that will blindside the players is that industrial regions controlled by the Extremists will only produce SQDs, controlled by Reactionaries will only produce PDFs, and controlled by Moderates will only produce AGs. The players will find this most distressing since invariably they will be prevented from producing the combat units they desire.
The three political parties are of course comic-book simplifications of any real-world party. This is for a boardgame, after all.
Extremists advocate using violence to enforce their will. So they like SQDs which are fleets of warships who go sailing into enemy space. The best place to defend your home is on somebody else's territory.
Reactionaries want society to return to the status quo ante. Conservatives, in other words. They have a fortress mentality, resulting in a preference for PDFs. The best place to defend your home is along your borders.
Moderates want a middle of the road strategy. AGs are sort of a Swiss Army Knife: it can do both jobs but does neither very well.
In the game it is possible to change the political party controlling a region, but it is a painful process. Basically you have to mistreat a region to the point where they are just one step away from revolt, then try to make the switch. Half the time they will not switch, instead falling into full scale revolt. The process of changing a political party is much like using a broken beer-bottle as toilet paper: it is possible if you are very careful but sooner or later you are going to be in a world of hurt.
This starts off with one section on the quick-n-dirty technique of cribbing one's warship types from historical naval units, then follows with a series of sections that actually study the problem and try to identify what sort of spacecraft warship types will actually exist.
Several analysis note that many science fiction authors have fixated on the terminology used at the time of the battle of Jutland. Then about 1977 the first Star Wars movie dragged terminology into World War 2 as the X-wings and T.I.E. Fighters fixated the authors on aircraft carriers.
Please note the difference between a ship type and a ship class. Ships with the same type have a similarity of intended use. Ships with the same class have a similar design.
For instance, the USS Carl Vinson's ship type is nuclear aircraft carrier but it is a Nimitz class vessel. The Starship USS Enterprise NCC-1701's ship type is heavy cruiser but is is a Constitution class starship.
The point is that in the US Navy many ships that are all of type "nuclear aircraft carrier" may look nothing like each other, but all of them are nuclear and can carry aircraft. But all Nimitz class vessels look almost identical.
For instance, the Nimitz Class nuclear aircraft carrier USS Nimitz is practically identical to the Nimitz Class nuclear aircraft carrier USS Carl Vinson. But neither look like the Gerald R. Ford class nuclear aircraft carrier USS Gerald R. Ford. The Toyota Previa Class minivan "Ralph's Car" is practically identical to the Toyota Previa Class minivan "Clarisse's Car". But neither look like the Volkswagen Microbus Class minivan "Floyd's Car."
Naturally ships of the same class must be of the same type.
The easiest way for a science fiction author to create the names for the various types of spacecraft warships in their novel is to copy them from World War 1 naval vessels. The "quick" advantage is that you will have your list of types as fast as you can copy them from Google or Wikipedia. The "dirty" disadvantage is that many of those ship types make little or no sense in future spacecraft combat. If this bothers you, see the sections below.
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. Form follows function and some of the functionality of a wet navy might be general enough to still be true in interplanetary space.
There are two broad catagories of ships in a fleet: Battle Fleet and Independent Units. Battle Fleet ships are always found in large groups (Task Forces), while Independent Unit ships generally operate on their own, apart from any fleet (in task forces whose size is one).
There are two broad catagories of ships in Battle Fleet: Main Units and Auxiliary Units. The main units fight. The auxiliary units assist the main units by supplying them with ammo or fuel, repairing them, giving medical attention to wounded sailors, etc.
If the ship has weapons, it is a warship (self-defense weapons do not count). All Main Units are warships, no Auxiliary Units are warships, Independent Units can be either.
Battle Fleet Main Units include Dreadnoughts, Battleships, Battlecruisers, Heavy Cruisers, Light Cruisers, Escort Cruisers, Anti-aircraft ships, Destroyer Leaders, Destroyers, Submarines, Submarine Minelayers, Minelayers, Aircraft Carriers, and Aircraft. "Dreadnoughts" were never an official type of unit but is included here as a tribute to E.E. "Doc" Smith, who spelled it "Dreadnaught"
Battle Fleet Auxiliary Units include Destroyer Tenders, Sub Tenders, Mine Sweepers, Seaplane Tenders, Fuel Ships (Oilers and Tankers), Supply (Logistics) Ships, Transports, Repair Ships, Hospital Ships, Colliers (missile supply ships), and Ammo ships. 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.
For a list of mondern day real-world naval warships, refer to TV Tropes Useful Notes: Types of Naval Ships.
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.
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 types 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.
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.
This is the results of my playing around with allocating WWII ship types on a ternary plot using my scheme of component priorities. Refer to the explanation above to learn how to read the graph. Briefly the graph displays what percentage of the total mass of each ship type is devoted to propulsion, weapons, and defenses.
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. The area marked "courier" can also be "fast scoutships", faster than the other scouts because they are totally unarmed. The entry I have as "rocket motor" also applies to "detachable drive" (see TV Tropes Standard SciFi Fleet under "Other Ships"). Ships with more than 75% weapons are likely warships with spinal mounts, that is: less a ship with guns than it is a gun with a ship built around it.
In reality, when mapping existing wet-navy ships onto the graph, there will be some holes. There are certain types 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.
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 capable in a fight is usually 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
A ship's "primary" drive is a slower-than-light propulsion used to move within a solar system. They are rated in gravities of acceleration. They typically have outrageous accelerations measured in hundreds of gs, so they are probably handwavium reactionless drives which also have handwavium anti-acceleration to prevent the crew from being squished into raspberry jam.
The "secondary" drive is the faster-than-light propulsion ("star-drive engine") used to travel between stars. They are rated in light-years traveled per day. They have the common limitation of having to move a certain distance away from a planet before the FTL drive can be used.
"Defensive screens" are handwavium force field to defend against hostile weapons fire. They have a strength per square meter of coverage. This is a function of the power of the screen generators and the surface area of the ship (i.e., take screen generator power and divide by ship's surface area). Naturally spherical ships have an advantage since a sphere has the smallest surface area per enclosed volume.
Weapons are often expressed in terms of proportional strength. E.g., a light-cruiser out guns a destroyer by three-to-one. They use lasers and missiles.
A ship design cost money to produce. There are designs that can theoretically be produced but are prohibitively expensive.
As near as I can figure:
"Dest" means "destroyer units". So a destroyer's screen generators are x1.0 of a destroyer's, and a light cruiser's screen generators are x3.375 of a destroyer's screen generators.
BB means Battleship. So a weapons rating of <BB means "out-gunned by a battleship".
- Type: class of ship
- Primary: slower-than-light engine gravities of acceleration
- 2ndary: faster-than-light engine travel in light-years per day
- Weapons: relative weapon strength where destroyer = 1
- Screen Gen: defensive screen generator power where destroyer = 1
- Screen Str: defensive screen strength per square meter of hull where destroyer = 1
- Dia: spherical ship diameter in meters
- Vol: ship volume in cubic meters
- Mass: ship mass where destroyer = 1
- Surface: hull surface area in square meters
- Surface: hull surface area where destroyer = 1
- LIGHT CRUISER : destroyer with hull increased to diameter of 150m but engines remaining the same size. Weapons and screens increased to take advantage of expanded volume. Advantage: can out-run a cruiser. Disadvantage: cost same as cruiser, cannot out-fight a cruiser because cruiser has more guns and screens due to smaller engines allowing larger weapon/screen volume.
- WAR CRUISER : battleship with hull decreased to diameter of 150m. Advantage: userful in certain defensive situations. Disadvantage: expensive, slower than a cruiser, cannot out-fight a battleship.
- BATTLE CRUISER : cruiser with hull increased to a diameter of 250 meters. Advantage: can out-run a battleship. Disadvantage: cost same as battleship, cannot out-fight a battleship because battleship has more guns and screens due to smaller engines allowing larger weapon/screen volume.
Unfortunately the novel is a bit vague the relationship between primary and secondary engine mass, percentage of ship volume, and speeds.
The role-playing game Traveller has an interesting variant on the The Tyranny of the Rocket Equation.
In our real-world universe where combat spacecraft use rockets for propulsion, spacecraft are huge propellant tanks with an engine at one end and some weapons bolted on. Orbital bases are not subject to the Rocket Equation Tyranny, since they have no rockets. So they can take the design mass budget ordinarily consumed by propellant and engines and instead use it for more weapons. Which means an orbital base out-guns a combat spacecraft of the same mass by several orders of magnitude.
In the Traveller universe, however, spacecraft use a handwaving reactionless drive ("maneuver drive"). Which means the Rocket Equation Tyranny does not apply to Traveller warships.
With one important exception.
You see, Traveller maneuver drives are only used for interplanetary travel, between planets in a given solar system. For interstellar travel, you have to use a faster-than-light "jump drive". As it turns out jump drives are subject to a limited form of the Rocket Equation Tyranny. They require absolutely huge amounts of hydrogen.
(What the hydrogen is required for is unclear. If it is used in a fusion reactor it means the smallest tramp freighter in Traveller in one jump burns 20 tons of hydrogen producing 380,000 megawatt-years of power, or about 160% of the energy the US produces in a single year. This is why some Traveller fans are retconing that the hydrogen is needed as coolant or something.)
The Jump-drive Equation Tyranny has two main effects on Traveller spacecraft combat.
First off, it creates a ship type called a System Defense Boat. They are warships with no jump drives nor huge jump drive hydrogen tanks. So like orbital bases they are more heavily armed than a combat starship of equal mass. System defense boats are also quicker and easier to build, since weapons are less difficult to construct than complicated jump drives. Not to mention all the expensive Lanthanum required for a jump drive. Large system defense boats are called "monitors".
The main draw-back to system defense boats is they are a major headache to shift between solar systems. For obvious reasons.
Which leads us to the second major effect on Traveller spacecraft combat. I give you the Battle Rider.
What you do is basically make a detachable jump drive. This takes the form of a "Jump Tender" which is a large framework capable of carrying multiple large system defense boats (called "battle riders"), along with a freaking huge jump drive and lots of hydrogen tanks. The tender typically carries six to eight battle riders. The jump tender transports itself and all of its child battle riders into a hostile solar system.
After entering the hostile system the battle riders detach and leap into battle with the hostile local system defense boats (or even better, with the hostile combat starships). The jump tender runs away from the battle and hides in a location it hopes is safe. It returns to its children once the battle is over. Or it escapes by jumping out system if all its children are killed.
The advantage is that the battle riders will be evenly matched against hostile system defense boats and will have an actual advantage against hostile combat starships. Also, spending your ship building budget on battle riders increases the number of spinal mount weapons you will get for your warship dollar (because each warship can only have one spinal mount. More warships per dollar = more spinal mounts per dollar). Due to the way the Traveller game mechanics treat spinal mounts, the side with the larger number of spinal mounts tend to win the battles.
The disadvantage is the cost of of building the jump tender. And the fact that if the hostiles manage to obliterate the tender, the battle riders will be up doo-doo pulsar with no gravity generator. The battle riders will be trapped in the solar system with no way out. Pure combat starships can concentrate on the battle at hand, they do not have to always be simultaneously trying to protect their jump tender. The tender is the "Achilles heel" of a battle rider squadron.
Even if the jump tender is safe, it still makes it difficult for the battle riders to escape a battle gone wrong by jumping outsystem.
If a group of combat starship jump into a system, advance into combat, then suddenly discover that they are seriously outnumbered, escape is possible by simply activating their jump drives and fleeing to another solar system.
If a group of battle riders discovers that they are heading into a futuristic reenactment of Custer's Last Stand, they have to
- Retreat under fire while suffering losses
- Fight a running battle back to the mother jump tender
- Hope they can latch on and be jumped outsystem before the hostiles scrag the jump tender
Or they can bravely do their best General Custer impressions and heroically allow the jump tender to escape.
The battle-rider concept has some vague similaries to Dean Ing's detachable fuel torus.
There have been a few articles written on the topic of "battle riders vs. Battleships" in various Traveller publications. The last I read the consensus was that the battle rider concept looks nice on paper but is at a disadvantage in real combat.
Some of the analysis suggests that it is more cost effective to have each jump tender only carry a single battle rider, to avoid stranding six to eight battle riders with the destruction of one jump tender. However this defeats the "maximizing number of spinal mounts" advantage.
Others suggest using combat starships on the front line and holding battle riders in reserve. This means battle riders called into a battle underway will be jumping into a known situation instead of possibly being fatally surprised.
These are huge web pages full of meat and impossible to pick out just a bit quote. The entire page is valuable. You will have to go there yourself and take notes.
These are huge web pages full of meat and impossible to pick out just a bit quote. The entire page is valuable. You will have to go there yourself and take notes.
TV Tropes Standard Sci-Fi Fleet (types of ships commonly seen as science fiction tropes).
TV Tropes Useful Notes: Types of Naval Ships (detailed analysis of real-world naval vessels)
These are huge web pages full of meat and impossible to pick out just a bit quote. The entire page is valuable. You will have to go there yourself and take notes.
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.