Amagi class Battlecruiser

The Amagi-class battlecruisers (天城型巡洋戦s艦 Amagi-gata jun'yō-senkan) is a series of twelve limited production battlecruisers (later was redesigned as Fast BB) built for the Terran Federation Space Fleet as part of the 2662 Fleet Expansion Program to replace the previous ship losses in the Thir Bug War.

Armed with a main battery of eight 51cm MACs and possessing thrust acceleration of 770.5G, the Amagi class were intended to be the Terran equivalents to the Petolemaic Fon'tek class Dreadnought Battleships. In addition to this, they were also the first dreadnoughts of Terran design to be classified as Fast Battleships, built to match with the new dreadnought battleships built by foreign navies.

Despite being outmatched by larger super-dreadnoughts of Turian and Asari navies in protection, the Amagi class is superior to these ships in mobility and firepower.

Armaments
The main guns of the Amagi class consists of eight Elanus M2662 Mark II MACs mounted in a ventral gunpod module, these large caliber guns could fire one of the most powerful nuclear shell ever developed by the Federation after the Third Bugs War. These guns are capable of firing an 80 kilogram Armor Piercing Polycrystalline Tungsten shell at approximately 1% the speed of light (3,050m/s). Other munition options includes Super Heavy Slugs, which comes in two variants, a High Explosive Nuclear Slug with a yield of 50 megatons each and a Shield Disruptor Slug with delayed fuse for better penetration performance against kinetic barriers. The secondary weapons of the Amagi class are 48 high density laser cannons mounted in 16 triple turrets, these guns are the same types used on many post-Treaty Terran cruisers and possess same level of firepower, but with lighter construction and shortened barrels for weight saving measures. These 152mm autocannons are used for close-range defense against smaller strike crafts. Because these are shell-firing machine cannons, they do not rely on the generator, thus these guns can achieve a high rate of fire. They also have the shortest range of all the ship's armaments, and due to their lack of penetration against larger warships, they were primarily used for shooting down light armored targets or missiles.
 * Elanus M2662 Mark II Mass Accelerator Cannon
 * Triple-linked 203mm Morita Type 99 Dual Purpose Laser Turrets
 * Twin-linked 152mm Morita Mark 12 CIWS Autocannons

Description
Designed and built after the disastrous losses incurred during the Third Bug War, the Amagi-class battlecruiser is considered the next leap forward in Terran naval technology, taking lessons from the previous two wars and applying them into a singular capital ship. In those wars, commanders of Federation battleships frequently found themselves outmatched by more agile and technologically innovative enemy dreadnoughts and as consequence would suffer extensive damage and loss of life because of it. The Amagi-class battlecruiser is a warship that seeks to rectify those issues by trading armor and density of offensive firepower for speed, agility, and the implementation of advanced alien technologies sourced from their allies in the Turian Hierarchy.

Vessels of the class has a markedly improved thrust-to-mass ratio comparable to contemporary Petolemaic and Turian dreadnoughts but hold a significant advantage over either in terms of raw firepower, bearing eight fixed 510mm Elanus Naval Armory 2660 Pattern Mass Accelerator Cannons mounted in a gun pod under the ships’ bow. Each of the eight cannons can accelerate its projectile up to .01c the speed of light when utilizing conventional shell types.

In support of these, the Amagi is armed with a total of forty-eight cruiser-grade laser cannons mounted in sixteen triple-mount turrets on the dorsal and ventral broadsides. Other offensive armaments include four short-range disruptor torpedo launchers on fixed forward-facing mounts on the port and starboard, as well as an aft-facing 152mm dual-mounted turret to protect the ship’s rear, in addition to the array of thirty-two micro-missile launchers serving as the point-defense system.

As a note on the defensive abilities of the Amagi, in order to bolster the class’ speed, significant tradeoffs had to be made in terms of size and armor density, however, to think that the class is any degree more vulnerable than a traditional Federation battleship would be a mistake as the class is among the first Federation warships to utilize kinetic barrier technology as an additional layer of defense.

Other technological innovations include a completely revamped computerized fire-control system utilizing highly accurate Turian targeting suites, as well as triple-redundant hardware systems reverse engineered from Turian techs now utilized throughout the ship. However, the greatest innovation, lies in the Amagi’s hybridization of the terrestrially sourced Cherenkov Drive with an Element Zero Core to utilize the galactic Mass Relay network while significantly increasing the speed and efficiency of unassisted FTL travel to a degree greater than that of any of the Citadel races. This expands the Amagi’s theoretical range to nearly anywhere in the galaxy.

In a post Third Bug War galaxy, many alien races see the Federation as a waking giant, and to that end, there is no greater evidence than the Amagi-class battlecruiser. A modern ship built on the failures of the past to lead a mighty charge for humanity onto the galactic stage

Kongo variant and specifications
Originally laid down as part of the Amagi class Battlecruisers for the Federation Fleet during the 2660 Modernization Plan, the Kongo class would have consisted of a quartet of four Battlecruisers, Kongo, Hiei, Haruna and Kirishima. However after a reassessment made by the Fleet regarding the Amagi designs following the commissioning of the T.F.S Takao, extensive changes were made to the next four ships and the final batch of four incomplete Amagi hulls, consisted of the Yoshino, Mikasa, Tsukuba and Ibuki.

The Kongo achieved a significant increase in mobility and maneuverability compared to the already mobile baseline Amagi Battlecruisers. Its hull is noted to have lighter constrution and significant mass reduction compared to its peers. To improve the maneuverability of the ship, the ship's primary fire control system was further simplified and the spaceframe had additional weight-saving measures incorporated. Other modifications include the removal of eight triple gun turrets inplace of sixteen QF 100mm laser turrets and the relocations of the side mounted torpedo tubes.

Compared to the baseline Amagi, the Kongo required 25% less time to complete a 180 deg turn, although the ship dropped speed significantly faster than the Amagi in a sharp turn due to its lengthened size at 640m. Protection-wise, the ship has reduced belt-armor thickness which would further tapered to cover a wider section of its sides, also in favor of a stronger frontal defense, the bow was reinforced with additional anti-laser coating and angled for better deflections against DEWs.

However, this would proved to be an obstacle for these vessels as the significant reduction in armor mass meant they are less likely gonna survive a hit that a normally robust-constructed Amagi which not only would have survive, but only sustaining heavy damage in worst case scenario. Subsequent ships have additional layers of anti-laser coatings to improve their survivability but it still raised concerns among Federation engineers whether it is worth it to sacrifice the durability of the ship in favor of a higher degree of mobility.