A/N: Finals are coming up and I'm swamped with work and studying. I know this isn't the Codex entry you voted for. That will come later. For now, have this thing I typed up a while ago.
[Codex-UNH]
[UNH-Military]
The Navy
The UNH fleet is a joint effort between all the members of the United Nations. Each Nation can build an unlimited number of unarmed starships, but any and all armed ships fall directly under UN jurisdiction and command. Even though the logistics support for the fleet is a unified effort, each country builds and manages a certain number of ships. The US, Russia, Germany, and China maintain and man the most ships, and tend to care for the heavy-weight vessels. The other countries, such as Japan, Australia, India, Korea, etc. tend to manage the mid-weight and lightweight starships. This is a form of accountability, because if one element of the fleet attempts to go "rogue", it cannot fend off the rest of the fleet. Each country's ships have certain design differences, both aesthetic and functional, but in general most ships fall under a certain type-designation.
Dreadnought [3 km]
The UNSS Eternity is Humanity's one and only Dreadnought. At 3 kilometers in length, it sits half-completed, docked in orbit around Mars. Started soon after the discovery of the Prothean ruins, the project was shut down due to "an excessive use of taxpayer money". It was designed around a massive experimental Antimatter core which would have allowed the use of a highly experimental directed energy weapon. Public speculation had the weapon pinned as either a Plasma beam, Ion beam, or Neutrino beam weapon. Unfortunately, the designer of the weapon died under mysterious circumstances, and the documents are classified. After First Contact, the UNH resumed construction of the Eternity, but the ship's main weapon is confirmed now as a battery of forward-facing railguns. The ship is not practical at all, and it is speculated that it shall serve as a mere flagship, nothing more. NOT ATMOSPHERE-WORTHY
Battleships [1.7+ km]
The largest class of mass-produced Human vessels. Average of 1.7 kilometers, and the heaviest of all the ship classes, battleships are the "damage sponges" of the fleet. They are equipped with countless guns, both for anti-fighter and anti-cap duty. While able to deal with ships of equivalent tonnage, these ships have the 2nd lowest DPS rate out of all ship classes, only "surpassed" by the Carrier classes. Battleships have a high survivability rate, and are meant to win a battle of attrition. They are slow, bulky, and hard to maneuver. Vulnerable to lightweight frigates, Battlecruisers, and bombers. Battleships are a demon against mid-weight ships, and a rival against fellow Battleships. There are only 5 Battleships in the UNH fleet, owned by the US, Russia, China, Japan, and Germany. Any other country that can build and maintain a Battleship is welcome to add one to the fleet. NOT ATMOSPHERE-WORTHY
Artillery [1+ km]
Artillery ships are essentially gigantic railguns with engines and a crew. Meant to stay at range and bombard the enemy, these ships are helpless against any short-range attack. They rely on a limited PDS and fighter escort to survive a battle. Artillery ships are managed by all members of the UN. NOT ATMOSPHERE-WORTHY
Heavy Cruisers [700+ m]
The slowest of the Cruiser-types, Heavy Cruisers have the most armor and weapons. They are meant to deal with ships of equal or lesser weight. Heavy Cruisers have a slight chance at prevailing against Battleships if they outnumber it, but Heavy Cruisers have the lowest survivability rate in the fleet. They have decent maneuverability, but cannot dodge incoming rounds with any effectiveness. Their nuclear arsenal can help in situations where they are outgunned, but they don't have many nukes. Equipped with PDS guns to fend off fighters. Heavy Cruisers are managed by all members of the UN. NOT ATMOSPHERE WORTHY
Battlecruisers [650+ m]
This ship-type is unique. It is about as armored as a Light Cruiser, but has the weapons of a Heavy Cruiser, and has the greatest Thrust-to-Mass ratio in the fleet. It can outrun anything that can outgun it, and outgun anything that can catch it. Equipped with PDS to fend off fighters, and nukes for emergency situations. While Battlecruisers were a failed concept in Naval Warfare, these ships are the "test case" for space combat. The ten Battlecruisers are equally managed by Germany and Japan, as no other countries wanted to risk the failure of such a ship. RATED FOR LOW-GRAVITY ENVIRONMENTS
Cruisers [600+ m]
The fleet-standard, this ship-type is equipped with medium weaponry. They have decent maneuverability, decent survivability, decent speed, and deal decent damage. They are the general front-line infantry, and screen the larger ships. Their heavier guns can deal with ships of the same tonnage, and their nuclear arsenal can help deal with capital ships. Their PDS guns can fend off fighters. RATED FOR LOW-GRAVITY ENVIRONMENTS
Light-Cruisers [550+ m]
These ship-types tend to have very light guns, light armor, but an impressive thrust-to-mass ratio. Light-Cruisers are so maneuverable that some Captains use their vessels to "dogfight" with enemy Frigates and Fighters. Light Cruisers frequently fill reconnaissance and scouting roles. These ships have no nuclear weapons, and are only equipped with a PDS system and a small battery of light railguns. RATED FOR 1G ENVIRONMENTS
Destroyer [300+ m]
Destroyers are pure Anti-capital ship Frigates. They have the armor of a Cruiser, and sport a deadly array of missiles, both nuclear and conventional. Their PDS systems are sub-par, but more anti-capital ship weapons take up the spare space, as well as maneuvering thrusters. Destroyers have a low survivability rate, but superior kill-to-death ratio. RATED FOR 1G ENVIRONMENTS
Frigate [200-400 m]
These ship-types are Anti-Fighter and Anti-Capital ship vessels. They have no PDS, but sport an array of light weaponry suitable for dealing with fighter craft, and harassing enemy capital ships. Some UNH Frigates possess an experimental Plasma Beam weapon for dealing with Enemy Caps. They are relatively short ranged, however, and require the target to be within 400 meters to have any effect. Frigates usually possess a few Nuclear missiles. Frigates have the highest maneuverability and speed in the fleet. RATED FOR 2 G ENVIRONMENTS
Corvette [100+m]
Corvettes are small 5-men reconnaissance craft. They are highly maneuverable, but lack decent armor or weapons. Unsuitable for combat. RATED FOR 3 G ENVIRONMENTS.
Carrier [1-2 km]
Carriers debuted on the Galactic stage at the Battle of Shanxi, otherwise known as the "Blunder at Shanxi", where due to a miscommunication, the Turians entered into a brief one-month conflict with UNH forces. Carriers are unique to Humanity. Fighter and bombers are not unheard of, and many Capital ships in the galaxy have a hangar to support them. The Carrier, however, is essentially one big Hangar, sporting no weapons except for a comprehensive PDS system. A single UNH Carrier can store 200-400 fighters and/or bombers. NOT RATED FOR ATMOSPHERIC FLIGHT
Fighter
A small one-person craft, Fighters are equipped with light guns that are ineffective against anything other than other Fighters. Can be equipped with missile weaponry, but is generally not. Can either be piloted manually or remotely. RATED FOR 5 G ENVIRONMENTS
Bomber
Larger and less maneuverable than Fighters, Bombers are equipped to carry a large number of nuclear missiles to deliver against a Capital ship. They require a Fighter escort. Can either be piloted manually or remotely. RATED FOR 4.5 G ENVIRONMENTS
Gunship
Gunships are two-person vessels, larger than even a Bomber. They are modular, and can be customized to provide cover from Fighters, or to assault ships-of-the-line. Can either be piloted manually or remotely. RATED FOR 3 G ENVIRONMENTS
The UNH fleet also has an extensive array of unarmed ships that provide Logistical support.
Defense Information
UNH vessels, prior to Shanxi, possessed no energy shielding. They relied on honeycombed Titanium (unless you're the Chinese battleship), which was capable of surviving multiple hits directly from a nuke (the Chinese battleship didn't survive a single one).
Upon seeing the tactical advantage of an Energy shield, the UNH ordered all ships to be equipped with their experimental Oscillating Particle Field Defense System. This provides an extra layer of protection, which could mean the difference between survival and death. The Field must be diverted around active weapons ports, however, creating vulnerable areas.
Propulsion
UNH ships use the Alcubierre Drive, or the "A-Drive". It works by using Negative Energy to bend space, allowing the ship to "Surf" on a wave of spatial distortions. Quantum Thrusters fuel the A-Drive, meaning that UNH ships often have to make "Fueling Cruises" around a star system before they can make the leap to FTL. Due to the nature of the drive, careful calculations must be made before travelling between star systems, so that the ship does not emerge in a decaying orbit around a star. Many early ships were lost to these mistakes. As a backup, all UNH ships are equipped with Ion Engines and Emergency Chemical Boosters. As a last-resort, all ships have Solar Sails that can be installed manually by technicians in EVA suits. Visually, when maneuvering using Quantum Thrusters, UNH ships look like they are sliding on ice. For more controlled maneuvers, chemical RCS thrusters are used. By necessity, all small interceptor and bomber craft are equipped with chemical rockets. They are much more efficient than their predecessors, and allow for rapid acceleration.
Weaponry
In the UNH, kinetic-kill weapons are the order of the day, in all shapes and sizes. This is supplemented by nuclear devices of varying magnitudes. The UNH has access to plasma weaponry, but it is impractical and just barely out of the experimental stages. A variety of Directed Energy Weapons are used as well, but the only ones that are standard are the Pulse Lasers installed on the fleet.
Fielded in significant but relatively limited numbers are "Smart Shells". Computerized projectiles interface with the targeting computer and surrounding sensor platforms to determine the proper distance at which to activate. The nature of these projectiles varies on the loadout, but they can range from anything to a shotgun-style round, an EMP bomb, a "smart" flak shell, Concussive rounds, Nuclear warheads, and other useful functions. They are extremely expensive.
