Eion-class carrier

The Eion-class carrier is a light carrier in service with the . Designed and manufactured due to the need for carriers of a light tonnage to operate with Outer Colonies defensive fleets as planetary invasion support and spatial supremacy, the Eion would serve diligently at the head of multiple squadrons and flotillas during the Insurrection, proving itself a durable and capable multirole platform. During the , the Eion-class would suffer severe casualties in the early stages, as one of the last few classes of capital ships to be fully withdrawn to the Inner Colonies. The few carriers that remained upon the end of the war would soldier on, until they would either be paid off into reserve or sold to UEG protectorate nations as the new flagships for planetary defence flotillas.
==Layout==
The Eion-class light carrier is similar to many other ships of the UNSC. Long, angular and covered in weaponry, the front half of the Eion-class is almost entirely built around the Magnetic Accelerator Cannon mounted in the front of the hull, with the command decks positioned further to the stern, near the fusion drives. The spacecraft hangars are mounted along the side of the hull towards the bow of the ship, with several transport and maintenance elevators/platforms connecting the hangars to the modular hangar/assembly bays at the stern. The armour of the Eion has been mounted at angles in certain areas to assist in protection, with thickness ranging from 1.2 to 2.1 metres of armour plating. The bridge is positioned, much like the frigates of the UNSC, in a raised area of the ship situated above the stern, directly above the fusion reactor. 
The hangars of the ship are interlocking with each other, allowing for greater ease of maintenance on ship systems and spacecraft. A large maintenance deck also exists below the flight deck for more serious repairs and refurbishments, along with storage-lockers containing all amounts of spare parts. Below the carrier decks is the ground forces assembly area, located within the large bulge mounted on the bottom of the hull. There lies most of the Eion-class carrier's dropship and transport aircraft, along with SOEIV drop pods and the heavy weaponry of the ground complement. 
The crew space for both flight crew and ship crew is located above the flight deck and in the bow of the ship above the MAC. The Eion-class has been purposely designed to use as much space as possible for a sizable arsenal of weaponry, spacecraft, and a decent ground complement, which helps make the Eion-class a very good multirole carrier, if a bit cramped.
==Roles and Tactics==
Whilst operating generally in a tactical niche that had gone unfilled by other ships in the UNSC Navy, the Eion-class still has a level of interchangeability with other UNSC carriers of light tonnage. The carriers she replaced, the Avalon-class escort carriers, were slow and unwieldy, although they did carry a sizable complement of both spacecraft and ground forces for them to be redesignated as amphibious assault ships and used in many planetary invasions throughout the Insurrection and Human-Covenant War. The Eion would usually be assigned either to assault battlegroups led by Orion-class assault carriers or Phoenix-class support ships intent on recapturing planets lost to rebel forces, or light hunter-killer task forces mostly composed of destroyers and frigates, hunting Insurrectionist merchants, mercenaries and pirates.
The Eion's large and oversized MAC was generally considered overkill for the hunter-killer missions, as most of her prey were around the tonnage of a corvette, leading to Archer missiles and even the point defence guns notching several ship kills to their credits. The lack of coilguns would see a gap in her offensive capability when attacking heavier vessels such as the rare Insurrectionist cruiser or even Covenant ships, as the MAC would often be the only weapon the Eion had capable of damaging an enemy.
Whilst the Eion-class would mostly be replaced by the much larger although less-flexible and older Noryang-class carrier, she would still have a role to play after the Human-Covenant War. Whilst the Noryang was built with fleet support and capital supremacy in mind, the Eion-class would soldier on as the heads of small expeditionary fleets attempting to link UNSC colonies that had lost communications without the galaxy at-large back with the UEG, a role in which the surviving Eions would serve in with distinction. However, the Created Crisis would again reduce the amount of operable Eions to a dauntless few, which would be sold to UEG protectorates to operate in their planetary defence fleets.The Insurrection would capture very few of the Eions, due to their large size and crew requirement. However, the few that were captured, either from drydock or geosynchronous orbit, would be used to great effect in raiding UNSC merchant convoys and smaller task forces. However, by the Human-Covenant War and the Insurrection's disbandment to assist UNSC efforts in combatting the Covenant, the URF Eions would be reintegrated into UNSC service, although with heavy modifications made by the rebel drydock technicians.
==Specifications==
===Propulsion and Powerplant===
The Eion-class are each powered by six fusion drives, two primary and four secondary. The two primary drives are the Argus Company's Melbourne-GEN4 DFDs, developed and named after the city Argus is based in. Similar to all fusion drives mounted on destroyers and cruisers, the Melbourne-GEN4 offers a substantial increase in power over the last generation of UNSC light carriers, the Avalon-class. Where the Avalons were unwieldy and slow to maneuver, the Eions were agile and maneuverable, able to keep pace with their escorts. They are aided by the four secondary fusion drives, made up of Direxion Propellants' Militant-14 DFDs. The same secondary drives on the Halcyon-class light cruiser and the Hermes-class surveillance cruiser, the Militant-14s were one of the best secondary fusion drives to be equipped onto CMA and UNSC ships during the pre-Human-Covenant War period. 
The powerplant of the Eion-class are two HAM-8145 . Manufactured by Hanley-Messer, this DFR is their successor to their substandard Mark II HAM DFRs that were mounted on the Halcyon-class and Hermes-class - A single HAM-8145 is able to provide 95% of the power that two of the previous Mark II HAM DFRs could. Complemented with Starwerx's FTL-278C , the Eion is one of the more adaptable and flexible vessels in the UNSC Navy, able to rush ahead of battlegroups with a small escort in order to either set up preliminary invasion operations, or engage an enemy fleet before the main fleet arrives.
===Armament===
The main armament of the Eion-class consists of a single Magnetic Accelerator Cannon, three dozen pods of Archer missiles, two fusion missile silos, and a combined point defence network of 96 single guns, split into 26 batteries. The main offensive armament is the Eion's 44F3A2 Light Coil MAC, a heavily-modified version of the MAC mounted on the Paris-class heavy frigate. With a lengthened barrel and the addition of a dozen magnetic coils, the 44F3A2 barely qualifies to be considered a Light Coil MAC, stretching for half of the ship's length. The Eion's MAC is capable of destroying any ship below its tonnage, with the exceptions such as the UNSC's cruisers (such as the Marathon, Halcyon and Valiant).
Its secondary armament is made up of thirty-six M42 Archer pods, each with twenty-four missiles per pod. The standard UNSC anti-ship missile, the Archers can be used to cripple and destroy other vessels, although against warships of cruiser-tonnage and above they can be ineffective against the thick armour. Scattered across the hull, the Eion's Archer are all centrally controlled from the combat command centre, located one deck below the command bridge. There are also two M4020 Bident nuclear fusion missiles mounted in silos on the hull of the Eion, to act as an intermediary between the lethality of the MAC and the numbers of Archers.
Its anti-fighter armament consists of eight batteries of M910 Rampart point defence guns, with each battery containing three guns each, and eighteen batteries of M810 Helix point defence guns, with four guns per battery. Interlinked via computer systems and a rudimentary 'dumb' artificial intelligence (more equivalent to a civilian personal assistant rather than a military-grade AI), the point defence network is automated although manual control can be assumed if the need arises, or computer failure occurs.
===Armour and Superstructure===
The Eion-class is protected by an average of 2 metres of Titanium-A1 armour plating. The thickest armour is positioned over the crew compartment, bridge and ground forces assembly deck, with thinner armour around the engines and unoccupied areas of the vessel, few and far between as they are. In the design phase for the Eion the utilisation of the honeycomb-armour structure used in the Halcyon-class light cruiser was considered, however rejected due to the interference in the ship carrier capability the brackets would have. Instead, a series of super-reinforced bulkheads are positioned within the ship, around the engines and hangars to protect the interior and the deuterium fusion reactor.
===Ground and Space Complement===
The Eion's function as a carrier is where the ship truly shines. The ship carries three squadrons of twelve C709 GA-TL Longswords, the larger fighter-bomber variant of the GA-TL. Also on board are two squadrons of C712 GA-TL Longswords, the interceptor variant of the UNSC's standard single-shipcraft. In terms of transport and cargo capacity, the Eion-class contains sixteen D77-TC Pelican dropships and six D82-EST Darters medium-lift cargo transports. If one squadron of C712 Longswords are removed, they can replaced by eight more Pelicans, six Darters, or six D96-TCE Albatross cargo dropships. The Eion-class also features six Clarion spy drones embedded in silos lined along the bottom of the hull, to act as forward scouts and give intelligence for the combat air patrol and any sorties mounted by the Eion's complement of spacecraft.
The ground combat capability of the Eion-class is quite impressive, rivalling that of other UNSC carriers and cruisers. Three composite companies of UNSC marines could be transported, along with an independent ODST company. Mechanised forces consist of 72 M12 Warthog FAVs and 20 M808 Scorpions MBTs, although two Pelicans can be removed from the ground forces assembly area and replaced with four M850 Grizzly MBTs. Whilst the Eion is not rated for atmosphere, it is possible to carry up to 12 light VTOL vehicles, such as AV-14 Hornets or UH-144 Falcons. The ground forces assembly area is also modular, capable of being converted into extra hangar space for Eion-class light carriers operating as purely space-oriented combat warships. 
==Blocks and Variants==
===Block I===
The Block I of the Eion-class were the replacements for the UNSC's early Insurrection-era escort carriers, such as the Avalon-class. With twenty in total commissioned, the ships would lead small hunter-killer task forces of warships for supplemental invasion forces for larger battlegroups. They often found themselves in support roles for the larger and more capable Orion-class assault carriers, however due to the Eion's speed and modularity/multirole capability, they would be used more often than Orions when adaptability and flexibility were required. Unlike later blocks, the Block I Eions would not be mounted with the modular ground forces assembly area, as that remained a static planetary invasion emplacement, and would only receive the modular assembly area in a refit in the late 2520s. They also did not have as much sensor equipment as Block II or Block III, and had issues with their point defence networks that wouldn't be fixed until a general Block I refit in 2536 for those that were left, after the heavy casualties taken during the first stages of the Human-Covenant War.
===Block II===
The second block of the Eion-class were the mid-war builds, all extremely similar in details bar a few details. Authorised by the 2526 Naval Authorisation of Armaments Act, a total of twenty-eight Block II Eions would be produced. Designed from the beginning with a modular assembly area for ground forces, the "Wartime Build" Eions would receive additional equipment in the form of two extra M910 Rampart batteries, an overhaul of electrical systems powering lighting, the anti-gravity generators and oxygen, and the installment of AN/SLQ-49 MAGICIAN countermeasure dispensers. Due to Covenant ships' far superior slipspace mechanics, advanced sensor equipment in the form of the AN/SPQ-58 multirole RADAR would be mounted on the vessel, although these were often dismounted and reused on other vessels during periodic refits, due to the AN/SPQ-58's often superfluous reliability issues when not mounted on the Hermes-class. The Wartime Build would be the workhorse of the UNSC's light carrier fleet, seeing heavy combat in the end of the Outer Colonies campaigns and the early incursions into the core of human space.
===Block III===
Block III would be the last block of Eion-class carriers built for the UNSC. With twenty-eight hulls cancelled in the aftermath of the Human-Covenant War, and another two destroyed whilst under construction at Reach, only eight would enter service with the UNSC Navy. Featuring the refitted RADAR systems that would be mounted to all remaining Eion-class hulls in 2544, Block VI would feature a number of passive improvements to its combat performance in the form of larger hangar doors for increased sortie capability, a second exit point for ground forces in the assembly area, and the enclosing of the bridge, removing the windows and replacing them with Titanium-A1 battleplate. Cameras would be placed in front of these plates to give them the necessary visibility, adding to the dozens of hull-mounted cameras scattered across the ship. She would also carry an increased complement of ten Clarion spy drones, rather than the standard six.
==Operational History==
In the late 2490s, the Insurrection was expanding at a rapid pace throughout the UNSC. The desertion of thousands of Colonial Militia personnel, and their subsequent capturing of heavy equipment and weaponry up to and including light-tonnage warships, posed a serious threat to UEG control of the slipspace lanes. With their growing fleet of warships and the use of pirates and privateers, the UNSC found themselves having to adapt to an unconventional anti-insurgency doctrine in space, organising convoys and escorts, gathering together hunter-killer groups of light ships and using their lighter forces and medium-tonnage vessels to combat the Insurrection's smaller fleet of ships. 
At the head of these hunter-killer groups were the newest carriers in the UNSC Navy's fleet, the Avalon-class light carrier. Small, agile and nimble, they could keep up with their frigate and destroyer escorts and were capable of destroying pirate and rebel flotillas, although not many Avalons were produced and lacked a significant complement of fighters or bombers. Whilst they would soldier on during the 2500s, they were too few and far between, and unable to carry out support missions to assist in planetary invasions and subjugation, as often Orion-class assault carriers either couldn't be spared, or was considered overkill for small frontier worlds. 
The UNSC proposed a solution to this problem, by pressing the few-in-number and doctrinally superfluous Noryang-class carrier into this role, as they had not displayed any excellence in operating as line carriers, orbital invasion support or even battleline capability. This would be successful, with the manoeuvrable and heavily-armed carrier proving itself adept at destroying Insurrectionist flotillas. However, the expensive production cost of the Noryang would ensure it never went into massed production (until the Human-Covenant War). This sent the UNSC to finally put out a request in 2508 for a new, light fleet carrier, with a maximum tonnage of 25 million metric tonnes and a length of 1,500 metres. This carrier, armed with a single MAC and copious amounts of missile pods and point defence batteries, was meant to fill the role of flagship of light battlegroups and squadrons hunting down privateers and Insurrectionist ships, and also, if necessary, assist larger carriers in a battleline engagement and orbital invasions. 
This request for designs would see the Reyes-McLees Corporation (RMC) and Martian Metals Shipyards (MMS) submit their own designs for consideration. The design submitted by RMC would ultimately be chosen, due to the design being lighter and ultimately more flexible in simulations, even if the overall offensive capability offered by MMS' Saracen-class escort carrier was far greater than the RMC's proposal, named the Eion-class. RMC would spend a further three months onwards from June 2509 redesigning several parts of the ship, such as narrowing the bow to reduce displacement, utilising angled armour to increase effective thickness (at the cost of comfortability and crew space) and the complete overhaul of the hangars, originally positioned in the rear of the vessel but moved forward to allow more space for the powerplant and ground assembly area. 
Authorised to begin construction on the first block of vessels, the RMC would lay down the first hull plates of the UNSC Eion in May 2510, with other carriers soon to follow in RMC's orbital yards across UEG territory. The Eion would be commissioned in September 2513, with the final flight numbering thirty vessels, all of which would be completed by 2519. They would serve dutifully as hunter-killer flagships, featuring in several significant victories over many Insurrectionist and pirate vessels they came across. They also acquitted themselves well in orbital operations, assisting UNSC fleets in recapturing rebellious worlds across the Outer Colonies. 
In 2525, however, all hunter-killer squadrons on patrol would be recalled to various UNSC fleet bases for replenishment and reinforcement, although were not informed of why. The UNSC during this time also martialed the considerable forces of the CMA they had recently usurped, and distributed their large fleet across their order of battle. Many sailors heard rumours on the mass redeployment: some thought it was a galactic-scale offensive against the Insurrection, others assumed an alien threat, whilst more conspiratorial minds believed the UNSC was about to launch a coup d'état against the UEG, or even declare a breakaway nation-state. They would be sorely disappointed however when the UNSC revealed the existence of the to the military and civilian populace. Immediately, plans for counterattacks and offensives against the encroaching alien forces were planned, with the heavy use of the hunter-killer battlegroups led by the Eion-class. 
In the early years of the war, the Eion-class would take heavy losses in the early, inexperienced and ill-planned offensives into neutral space, or the large glassed areas of former UEG space. They would not prove especially capable leading small flotillas against other Covenant squadrons of equal or even smaller size, due to the huge technological disparity. Instead, they would find a new battlefield niche of capital support. Utilising their complement of single-ship fighters to assist and reinforce UNSC fleet strike craft operations, and their heavy arsenal of weaponry to provide support to the larger carriers and cruisers of the fleet in a battleline, the Eions would see success in this role, assisting in the destruction of Covenant ships and using their considerable ground invasion capability to turn the tide in planetary operations. 
A second and third block of the Eion-class would be commissioned during the war, each featuring incremental upgrades and developments in capability as the war progressed and Covenant technology was reverse-engineered and implemented into the field. A total of 78 Eions would be brought into UNSC service, with another thirty planned although never completed: the third block was laid down so late in the war, that the UNSC's principle shipyards were mostly overrun, leading to the third flight being cancelled after eight vessels were completed. By the end of the war in 2552, the amount of Eion-class in service had been heavily reduced by the war, however they were still the most numerous UNSC carrier in service, thus leading to a new era in which the Eion would shine. 
For several years postwar, the Eions would lead new expansion and hunting fleets throughout human and neutral space, rooting out Insurrectionists, Covenant remnants and other mercenary forces, clearing the way for the UEG's eventual recolonisation efforts. However, by 2558 the Eion had mostly been replaced in the role of flotilla leaders by more numerous carrier designs, dropping them back into the fleet support role. During the , the Eion-class would be further reduced by Created forces, leading to them being reduced again in number by 2560 and the fall of Cortana's empire. Despite their age and the technological obsolescence of their design, the UNSC's lack of fleet assets would see the remaining Eions refitted to a modern standard and pressed into service once more, operating with UNSC task forces and protecting the citizens of the UEG. There is no expectation for the remaining Eions to be replaced for the foreseeable future, due to the severe state of the UNSC fleet's order of battle. 
==Ships of the Line==
Name 	Hull Classification Symbol	Commissioned	Destroyed 	Notes
Block I
The Insurrection block of the Eion-class light carriers, commissioned between 2513-2517. Assigned hull codes CVL-143-CVL-162.	Block I
The Insurrection block of the Eion-class light carriers, commissioned between 2513-2517. Assigned hull codes CVL-143-CVL-162.	Block I
The Insurrection block of the Eion-class light carriers, commissioned between 2513-2517. Assigned hull codes CVL-143-CVL-162.	Block I
The Insurrection block of the Eion-class light carriers, commissioned between 2513-2517. Assigned hull codes CVL-143-CVL-162.	Block I
The Insurrection block of the Eion-class light carriers, commissioned between 2513-2517. Assigned hull codes CVL-143-CVL-162.
Eion 	CVL-143 	2513 	March 2526 	Destroyed during the Battle of Biko.
Millennia 	CVL-146 	2514 	July 2545 	Destroyed during the Second Battle of Tirana.
Mary Rose 	CVL-160 	2517 	N/A 	In service with the UNSC's .
Block II
The main wartime blocks of the Eion-class light carriers, commissioned between 2542-2551. Assigned hull codes CVL-269-CVL-308.	Block II
The main wartime blocks of the Eion-class light carriers, commissioned between 2542-2551. Assigned hull codes CVL-269-CVL-308.	Block II
The main wartime blocks of the Eion-class light carriers, commissioned between 2542-2551. Assigned hull codes CVL-269-CVL-308.	Block II
The main wartime blocks of the Eion-class light carriers, commissioned between 2542-2551. Assigned hull codes CVL-269-CVL-308.	Block II
The main wartime blocks of the Eion-class light carriers, commissioned between 2542-2551. Assigned hull codes CVL-269-CVL-308.
OdysseusClaimed by 	CVL-270 	2542 	 	
Chained to a CloudClaimed by	CVL-273 	2543 	 	
 	CVL-277 	2544 	August 2552	Destroyed during the Fall of Reach.
Block III
The final block of the Eion-class light carriers, commissioned between 2552-2556. Assigned hull codes CVL-345-CVL-364. Only nine would be completed.	Block III
The final block of the Eion-class light carriers, commissioned between 2552-2556. Assigned hull codes CVL-345-CVL-364. Only nine would be completed.	Block III
The final block of the Eion-class light carriers, commissioned between 2552-2556. Assigned hull codes CVL-345-CVL-364. Only nine would be completed.	Block III
The final block of the Eion-class light carriers, commissioned between 2552-2556. Assigned hull codes CVL-345-CVL-364. Only nine would be completed.	Block III
The final block of the Eion-class light carriers, commissioned between 2552-2556. Assigned hull codes CVL-345-CVL-364. Only nine would be completed.
Warning ShotClaimed by 	CVL-270 	2551 	August 2552	Destroyed during the Fall of Reach.
== UNSC Remarks==
==Notes==
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Category:Carrier classes
Category:UNSC Ship Classes
The Eion-class carrier is based off of the light carrier of the same name in the mod Sins of the Prophets, made for the RTS game Sins of a Solar Empire: Rebellion. The author of the article in no way claims to have ownership over this intellectual piece of media, and any and all pictures and images used in the article are the property of their creators, used in the article to expand upon a concept created by the SOTP dev team.