Heimdall-class Frigate

The Heimdall-class Frigate was the first new ship design of Reyes-McLees Shipyards prior to the Remnant War, being a test bed for what was soon to be normal technology for capital ships. Sangheili and Huragok technicians finally created not only highly improved reactors, but also an adaptable shield generator, making it the first UNSC vessel to be outfitted with an energy shield. Outwards, it appeared only slightly different from the older frigates of the UNSC and retained similar armaments.
The first ship of the line, the UNSC Heimdall, saw action while on patrol at Kanna, destroying a pirate frigate in a trade of fire and crippling another. The ship soon entered mass-production, with existing frigates being refitted into Heimdall-class vessels. In co-operation with Shaw-Fujikawa Drives Inc., it was out fitted with the Model 52, a highly improved slipspace drive formerly used only on experimental vessels. It was further armed with a powerful AESA RADAR, threat detection LIDAR and a electromagnetic sensor which can pick up traces of thermal energy and energy spikes from slipspace and energy weapon operations. The ship is also contains HOPE launchers for high orbit or low level insertion.
The technology and construction of the Heimdall-class would later become the standard for all UNSC warships, leading to a new generation of highly stealthy warships designed to fight both small-scale 'bushfire' wars against rebel elements, and fight larger scale battles against more powerful Covenant warships, by maintaining stealth and electronic dominance.
==External Layout==
Externally, it features the standard layout of a UNSC vessel, being largely narrow and focusing on length over width in design. At 496 metres long, 152 metres wide, and 113 metres high, with a weight just under 4317 tons it follows the standard doctrine of UNSC tactical thinking. On its prow, it mounts a two pronged section, with the upper segment being a hive of heavy armour covering the frigate's Magnetic Accelerator Cannon. Under this is a secondary prow, carrying a nuclear missile launcher. It carries a number of antennas for radio and slipspace communication, and more for RADAR sensor systems.
On the main hull it features two bulked out, well armoured ship bays, holding the Super Sabre escort fighters and a handful of the Pelicans. On top of the area it holds a decoy 'bridge', as the bridge is actually buried deep inside the ship. This area carries the observation deck and the MASER systems, a large, powerful MASER dish and the primary RADOME on the ship, along with auxiliary systems and a docking port. Beneath this is the characteristic troop bay, a section that holds the company of Marines, a number of armoured vehicles, the majority of Pelicans and their drop bays, and landing platforms. The drop bays are used to drop a Pelican out of the Frigate by gravity, while the landing platforms are elevators that descend to deploy any on board vehicles.
Towards the rear of the ship it features, on each side, a large, well armoured engine shield, protecting the relatively delicate engine and drive section of the ship. Both of these are kept in the most heavily armoured segments on the frigate. From this come four vectored thrust engines, two providing the main thrust then two providing the majority of manoeuvring power.
On each the flank of the ship is the tell tale, bulky launch bays. It carries six bay doors on each side, twelve in total, with enough room internally for the twelve Super Sabres, ten Scimitar drones and three Perceptor reconnaissance drones. The internal bay has, along with fuel tanks for refuelling the vehicles, cranes that can be used for repair and reloading, along with numerous technicians equipped with Wolf exoskeletons for heavy lifting. This allows the Sabres to be refitted with other missiles and equipment for varying flight missions. All ordnance is carried in conveyor belt bays under the cargo bay, providing on the spot ordnance change. Separate hangars exist in the Marine 'strut' for deployment of Pelicans for combat operations. Drones are stored on a overhead rack with built in reloading and refuelling systems, allowing them to be lowered and launched, by dropping them straight out the lower bay doors.
All the external corridors of the ship hold air expanding foam to expand in case of hull breaches. There are also a number of external and internal bulkheads that can be sealed to ensure the ship remains air tight or deter boarders.
==Internal Layout==
Internally, the layout is conventional, with the sleeping quarters set towards the prow of the ship, the Cryo bays being located starboard to it and the recreational area on the port-side. Behind this are the copious food and water storage areas, with the food being stored in refrigerated area and the water using the run off from this to remain chilled and kept secure in a titanium aluminide tank, to give it some protection in case the Warship is struck and protect the main reactor. On the underside of the barracks area it holds a reloadable High Orbit Precision Entry Vehicle Launcher and briefing room/armoury. In the mid section, above the infantry spur, is the main cargo area, which can carry extra food and water supplies, allowing it to be used as a emergency relief vessel. It can be outfitted with extra barracks and Cryo tubes instead, allowing them to support another company or two, depending if extra vehicles are loaded or not, and can even take large tanks of extra fuel. Beneath this is a large, almost foot like spur, which is so nicknamed the 'ground pounder's foot'. This area belongs to the Marines and houses their own barracks, cryotubes, vehicle bays, workshops, armouries, repair bays, 'dead drop' Pelican bays, and landing platforms. The stern holds the massive Plasma-Fusion Drive and the Model-52 Shaw-Fujikawa Slipspace drive, protected by the massive 'engine shields'; large armour plates that protect the vessel from harm. Underneath the engine and covered by the lower forward shield is the life support systems and the main oxygen tank. The bridge is set above the main superstructure, set on an independent structure containing the bridge, mainframe, main docking portal, communications, sensor and system controls. The bridge has a typical set up for a small warship with a commander's chair, a Weapons officer's station, Navigation officer's station, Operations officer's station, communication officer's station, multiple optical sensor displays, 3-D mixed radial sensory display and a holotank. Beneath the Bridge is the ship's mainframe, consisting of four cryogenically cooled data stacks, acting as servers for most of the autonomous ship functions and ADIS system, as well as allowing the A.I. to boost its functionality. Both the Bridge and Data Core have one meter of armour plating.
==Armament==
The Mark VIII Light Coil Magnetic Accelerator Cannon constitutes of a long, smooth bore barrel which is ringed with electromagnets. These are charged by capacitors held to the rear and then these are dumped into the electromagnets in an ordered fashion. A huge amount of current is put through the first solenoid which creates a strong magnetic field which attracts the metal slug that has just been fed by an auto loader. As the slug passes into the solenoid, the solenoid is quickly turned off and the second solenoid, which is further up, turns on, which attracts the now high velocity metal slug just like the first solenoid, and the process is carried on. By the time the slug is fired out the end of the barrel it has been accelerated to 45,000 metres per second. Needless to say, a slug weighing as much as 600 tons, or more, can be shot out at a high velocity. The MAC is mounted in a linear fashion along the length of the ship, taking up almost half of its length. The ship is armed with an autoloader, using a series of magnetic lifts to pull up the required ammo, usually a Ferric-Tungsten round, utilising Tungsten with elements of steel in it to provide a cheaper but strong slug. This is the most popular slug for use, displaying optimal penetrating power. It can also fire Depleted Uranium slugs, which are easily the most effective slugs, but are the most dangerous to use, as repeated and heavy exposure can cause illness alike to exposure to other radioactive materials. Another munition it can use is the Splinter Slug, which is primarily used against capital ships where the aim is to disable or cause more damage over a large area. It is made up of seven individual slugs held together by nitrocellulose which, upon the friction heat of acceleration, is combusted. It results in a shotgun like blast that tears apart ships. All the slugs used are 'hammer head'-type slugs, with a flat, snub-nose, designed to transfer as much kinetic force from the slug into the ship, shattering the internal structure and shaking the ship apart. The MAC can also fire more exotic Kinetic Penetrator Incendiary slugs, designed to vaporise into a high yield plasma explosion, with similar yields to nuclear explosions.
The ship also mounts 50 Archer pods, each carrying 24 RSM-131C Archer missiles in a rotary launcher. The Archer missile, having been thoroughly modernized, is now a much more capable weapon, using a boosted warhead consisting of nine explosively pumped flux compression generators. These unleash an EMP burst upon impact, with the EMP yield increased greatly by the transformer-like aluminium coils around them. The rest of the warhead is coated in TRIDENT, a light, composite metal, with a primary warhead utilising a forged fragment ring for penetrating the hull. After that is the third warhead, containing a number of penetrating rods covered in tungsten carbide. These punch through several decks of the target, causing serious damage. While the head is made out of solid tungsten carbide the sides of the penetration rods are made of forged tungsten fragmenting shell, designed to fragment and cause much more perforation of the ships internal systems with the RDX filler goes off. The Archer is now upgraded with a number of systems to help it bypass an enemy's defence system, such as jet coolant systems, drastically reducing its heat signature, advanced armour mostly focusing on heat resistance, using heat resistant polymers and a titanium-aluminium heat matrix, and a set of second stage boosters for a sudden burst of speed upon terminal approach. For those systems that jam Archer missiles, cutting them off from the ships that launched them, they now have infra-red sensors and millimetre wave RADAR, allowing it to home in without the launcher's assistance. To this end, the Archer capabilities has been greatly improved, being both more destructive to shields and hulls of ships and being harder to detect and destroy. Archer pods are arranged on nearly every surface of the ship, providing an all-round firing capability. The pods are arranged into groups of five silos, with eight silos all together. There are two silos on the port side of the MAC, two on the starboard, one on the port side and starboard sides of the engine shields, two behind the manoeuvring engines on the flight pods, facing to the keel and two on the rear rib supports, facing to dorsal region. 
The complement its fire power, it is armed with 14 M37 Rampage Light Naval Guns and four M54 Lancer Naval Support Energy Weapons. The M37 Rampage consists of an automated turret with two Magnetic Accelerators firing 120mm slugs. These cannons have a relatively high accuracy and fire at high velocity, causing severe damage on impact. The gun has a high rate of fire, using multi-shot capacitors to achieve rates of fire necessary to cause significant damage to unshielded ships. The twin barrels fold into the turrets main construction to reduce the ships RADAR profile. The guns are self contained, with their own ammunition and sensor modules. The M54 Lancer NSEW is centred around two HYPERION two-gigawatt Free Electron LASERs, which causes severe thermal and kinetic damage on impact. They are extremely accurate and especially destructive against enemy outboard systems such as weapons, engines, hangar bays, bridges, sensors, and remain effective at crippling the enemy's ability to fight at range. These also fold into the gun, and again have self contained sensors. There are six Hailstorms on each flight pod, on the dorsal and keel surface, giving it tremendous broadside fire power, with two facing towards the rear, allowing the ship to harass pursuing or flanking ships. The Lancer NSEW are mounted on raised platforms on the flight pods in a similar fashion, giving them the same firing arcs as the lesser guns. 
The ship's primary layer of active defence against inbound missiles and fighters is the Windstorm Close-in Weapon System. The Windstorm is built up from a turret with two M288 rail guns, with a AURORA LASER mounted on the turret assembly. The turret assembly utilises a LIDAR, clusters of optical, UV and thermal imagers, and a millimetre wave RADAR to identify targets. The Windstorm achieves its rate of fire through the sheer number of rail guns and when firing snub nosed slugs with incendiary effects, it causes heavy damage to space craft. With the upgrade to XM301 rail guns, it now achieves a huge rate of fire, allowing Windstorm turrets to lay down swathes of deadly fire, accelerating an array of deadly slugs to high velocity, in space conditions. The turret usually fits KCP, KWP and KPI slugs in a 3:1:1 ratio.
The Firestorm Close-in Weapon System is a point defence weapon for warships to defend against fighter craft. The weapon is made up of a TITAN Laser and a and an AURORA Laser held on a mount on top of the weapon that is turreted separately. These are guided by a computer controlled guidance package, utilizing a mixture of millimetre wave RADAR, thermal imagery, jam homing, optical and LIDAR. The weapon is operated by the Area Defence and Interception System that allows the Firestorm to be set up in to act in coordination with other guns. These weapons can pulse almost 300 times a minute. 
The ship further mounts a number of Thunderstorm Close-in Weapon systems. The Thunderstorm Close-in Weapon System is a point defence weapon for warships to defend against fighter craft. The ADIS prioritizes and targets incoming fighters and fires RIM-13 THORN missiles, relying on its dual optical and active RADAR to home in and its stealth to ensure impact. The missile can be set to 'ambush' after a short distance. This can be done on order of the weapons officer or AI to create an 'active minefield' partially or fully surrounding the vessel. The Thunderstorm CIWS is to provide capital ships with a long range fighter defence. Whereas the optical range of the Firestorm is short and limits its use, the Thunderstorm has the reach to more efficiently defeat fighter constellations. While the Firestorm can usually only engages enemies that have unleashed their payload, the Thunderstorm can engage them before they even gain formation. The Thunderstorm is used in one of three ways; this first is through direct fire, using the frigate's on-board LIDAR, millimetre wave RADAR and thermal imaging to target and prioritize targets and fire directly upon them, even when they are hiding behind asteroid cover, smoke screens or gaseous clouds that can effect the effectiveness of the Firestorm. The missiles can be used as traps, as they are virtually invisible when cruising or stationary, allowing them to spring into action. Lastly, they can ambush enemy ships at a close range, eliminating them before their defences come on. The Thunderstorm CIWS fires RIM-13 THORNs, which uses dual optical and active RADAR to seek out targets, with three stage rockets. The first is the primary launch booster, the next is the cruiser booster and finally the hyper velocity booster, accelerating it to hyper velocity. Upon nearing the target it releases a spray of flechettes to ensure the target is crippled or destroyed. Much like the Archer, it is coated in ablative resin to hide its presence and jet coolants to hide it during the second stage of 'cruising'. 
Usually, depending on the ship it is arranged on, they are set up in phalanxes of four, with the two Windstorms as 'primary' targeting systems and the Firestorms on 'over watch'. The first two are the priority guns, disabling or destroying the first enemy contacts and the Firestorm on over watch, covering them as they reload, or cool down, and engaging high priority target. They work in coordination with other phalanxes, point defence lasers and other defence systems to engaging and destroying oncoming fighter and missile constellations. The computer trackers keep up with enemy targets. No 'pre-emptive' fire is needed due to the hit-scan or near hit-scan nature of the weapons. They are positioned tactically to provide all round protection on the ship. On each docking bay there is a phalanx on top and on the bottom, to the forward and the aft, there are two on the rear, between the engines, there is one of the top deck, in front of the MASER dish and one on the keel on the strut. This gives near all-round protection against missiles and fighters.
The keel strut is armed with a launch tube and rotary loader, allowing it to load and fire three RSM-103 Wayfarer Tactical Weapon Platforms or three RSM-107 Vagrant Tactical Weapon Platforms. The Wayfarer missile is a long range nuclear missile, mounting a W700 AVENGER nuclear fusion warhead, W705 VENGEANCE nuclear EMP warhead, W905 APOCALYPSE anti-matter warhead and W1001 APOSTASY MIDAS warheads. The missile has its own onboard guidance and command communication link, allowing for course correction by the ship, or allied platforms. The Vagrant platform is a similar missile that is equipped with a slipspace engine, increasing the price exponentially, but allowing it to perform long range strikes, even from outside the system that can arrive suddenly and destroy without warning.
Four years after their initial introduction, all frigates in the Heimdall-class became test beds for the Sharpshooter Missile Pod system and Marksman Kinetic Energy Weapon system, devised to provide light, accurate space-to-ground fire, in support of planet-side Marine forces. The Marksman pods use a specially-designed air-to-ground cruise missile system, intended to strike specially designated targets designated by forward Marine Forces at extreme ranges. The missile system can be independently steered by space, air or ground forces, or 'locked in' and directed to a specific target by War Net references, using a mixture of RADAR, optical references, LASER receivers and GPS to home in on its target. The Marksman missile can take a variety of warhead loads, preloaded inside the launch tubes by automated systems, with the potential explosives including a bunker busting munition, submunitions dispenser (with sensor fused warheads for engaging and destroying tanks, AT/APERS mine dispensers for tactically declining a area to enemy forces and incendiary flechettes for destroying enemy materials on the ground), and a high explosive warhead, for destroying large areas and devastating enemy held structures. The missile has both active anti-countermeasure systems, stealth design, RADAR/LIDAR/infrared-resistant painting, cool air/coolant bleeders and a thermal shield to protect it from heat and ordnance during terminal approach. The Sharpshooter pod was based upon the successful ASTEROID and METEOR Kinetic Bombardment Weapon systems. The pod has storage for three 'heavy' Kinetic Rods and seven 'light' Kinetic Rods, giving the user a variety of bombardment options. The Rods use a computer controlled launch system, using eight sets of control surfaces and a primary rocket booster, allowing it to accelerate to high speeds (10 kilometres per second) and can strike just about any target within range. Light rods can cause explosions roughly similar to 500 pound bombs, and can be used to directly support marines in combating aircraft, entrenched positions or tanks while the larger pods have a blast yield nearer small scale nuclear warheads, allowing it to devastate large areas in preparation of marine landings or to defend marine ground forces.
The Prometheus-class was a subclass that was fitted with a W/AS M21A 'Tsunami' Ion Cannon in place of the usual Magnetic Accelerator Cannon. The Tsunami Ion Cannon works by ionizing hydrogen gas by either stripping an electron off of each hydrogen atom, or by allowing each hydrogen atom to capture an extra electron. When hydrogen gains electrons it forms anions. The weapon accelerates anions uses a travelling wave type particle accelerator. In this kind of ion accelerator, the negative ions are released inside a cylindrical ion acceleration chamber. This chamber has an electrode with an alternating electric charge of up to 1,000,000,000 (109) volts inside it. While the charge on the electrode is positive, the ions are attracted to the negative charge on the electrode, and thus bunched around it. The alternating voltage switches the charge to negative on the accelerating electrode. The negative charge electrostatically repels the negative ions and accelerates them to near the velocity of light. The resulting high energy beam of anions passes through a chamber filled with low pressure gas, where collisions with the gas strip the extra electrons from the anions, and thus make the particle beam neutral. The particle beam proceeds straight to its target, and damages it by running into it, and by disrupting the structure of the target with its kinetic energy. The weapon has the background effect of Electromagnetic Radiation. The Weapon is often used when the ship needs to hit far above its weight, being capable of disabling the shielding of much larger warships, and crippling them with electromagnetic interference.
==Engine==
The engine is a Plasma Fusion Drive. This is a next-generation engine, being used on both UNSC and USR craft as a joint venture between the two. It uses both the older Covenant technology of fusion of Deuterium and Tritium and older UNSC Technology of Deuterium Fusion. The Covenant technology used fusion of the relatively abundant material and the rarer material to create mediocre levels of energy, but this was superheated and fed through magnetic fields to create plasma, which produced an over abundance of thermal energy; meanwhile the UNSC used deuterium fusion to create high levels of energy, although nothing on par of the Covenant reactors. The ship carries a UAE Systems EA-23 Engine, an engine that featured two smaller Deuterium Fusion reactors around a larger 'Dry' fusion reactor, capable of boosting power output by 480%. An upgraded cooling system is fitted as standard, featuring a laser-induced optical slurry of ions chilled to near-absolute zero that removed the reliance on expendable chemical coolant agents. In essence, the new system provided increased waste heat removal as power output increased. This self-regulating and self-cooling system was critical in combat since it virtually eliminated a commander's concerns about overheating and slagging a ship's engines. The two super charging reactions use conventional deuterium on deuterium reactions to create high levels of energy. These are cryogenically stored in compressed forms when not in use, as the need to use these engines is rare. The primary engine uses Lithium hydride fusion plant, using the crystalline powder form of LiH. The gravity of the fuel is 0.82 metric tons per cubic meter, making it extremely efficient, meaning it is superior to the need to store deuterium cryogenically or as plasma. The fusion plant accepts the LiH in the powdered form, which is very fine, allowing it to be transported and pumped like a liquid, though it must be sealed within double lined containers to prevent contact with water, as even the slightest amount of moisture can cause it to dissociate and react violently.
What powers the reactor is that very dissociation reaction, which liberates extremely large amounts of energy from the fuel with no waste product. The Lithium Hydride is split and forms into Tritium, with the aid of free Neutrons then this is combined to form deuterium, which is split again, combining once more. This cycle releases enormous amounts of energy and leaves no waste product behind. The activation energy for this is high, but is secured by the two deuterium reactors. However, in order to contain this, magnetic containment fields are needed, but the densities and confinement times needed are higher than conventional fusion reactors. The core temperature is usually around 600 million degrees Kelvin, and densities are maintained at around 5x1014 nuclei per cubic centimetre. With typical conversion efficiencies this yields around 130 megawatts per litre which is delivered as electrical energy, mostly generated by magneto hydrodynamics couplings. Fuel consumption is around about one sixth of a milligram per second per litre. At that rate, the 600 metric tons of fuel will supply the plant for a year while running at maximum power. The entire reactor is covered in lead lined titanium, hiding its radiation emissions. The heat radiation is dissipated through the primary heat sinks, which have a running time of two days, before reaching super-critical conditions. These heat sinks support both the reactor and the life support systems, keeping the two hottest operating systems chilled. However, after constant operation, the heat sinks make the interior of the ship hot, and the heat ejection process ensures the crew, or delicate systems are not damaged by the heat. The heat sinks are surrounded by a bed of heat absorbing systems, that turn the heat energy into electrical energy, storing this power in the emergency generators. The heat sinks are stored in cylinders surrounded by a Doppler cooling system, using chilled LASERs powered by its own heat to cool down the heat sinks, allowing it to forestall the inevitable overheat. If the ship steps down it's power needs, the sinks will return to room temperature, with the power transfer and Doppler cooling systems bringing the temperature back down. 
The primary UAE rocket motors used for sub light travel and manoeuvre are powered directly by the fusion drive, simply by a reaction mass which is placed in contact with plasma from the main reactor, which heats it. The heated gas is then expelled, moving it forward. The reaction mass is industrially created carbon-diamond which sublimates easily in the high reaction heat and creates gaseous thrust without requiring combustion. Carbon Diamond is preferred to water and other reaction masses as its easy to manufacture and its high density. One major problem with water is the possibility that it can spring a leak and react with the stored LiH, blowing the ship sky high. It leaves no radio emissions wake as it cools, through a mixture of the small size of the particulate exhaust gasses an the spiral exhaust nozzles, which scatters the exhaust gasses over a wide area, rendering them an overall much smaller target for potential RADAR detection, leaving the engine undetectable until it is within a few kilometres of a sensor. Thrust is controlled by changing the flow rate of carbon through the engine. High flow rates results in little heating and a high thrust, low efficiency burn. If the carbon mass comes to equilibrium with the plasma it creates a low thrust high efficiency burn because of the lower flow rates. When running at top speed the engines can easily shift the ship with a power to weight ratio of 124.1 to 1. Due to the fact it eats fuel at a high rate, these are only used during battle or emergencies with gentler, fuel efficient burns preferred. During cruising it is preferred that the ship drifts, sustained by short bursts from the engine.
The rocket motors feature vectored nozzles, using four vectored plates of heavy duty heat resistant ceramic materials. These are arranged diagonally, on the engine, allowing it to more agilely move on both the Y and X axis at the same time, greatly improving manoeuvring during combat situations. The primary rockets are not used for manoeuvring as much, preferring to use the manoeuvring rockets for such duties, as some manoeuvring on the primary rockets is expensive on the fuel.
The Primary and manoeuvring engines are supplemented by forward manoeuvring thrusters, with three way vectored nozzles. These increase its agility even more, giving the ship a wide range of agility options.
The engine outlets have infra-red suppressors to disguise the engine flare. These mask them from being detected by thermal sensor systems. The engines themselves are covered in a Doppler cooling back, using super chilled LASERs to cool the engine by Doppler effect. 
A secondary back up systems exist, four UNADS CV-5 magnetohydrodynamic turbines which can generate 30 to 40 megawatts each. these can substitute the main reactor or the booster reactors in emergencies and are situated beside the launch bays.
All of the chemical thrusters are supplemented by liquid Bismuth fed Electron Ion thrusters, with engine shroud. Due to the fact that Electron Ion Thrusters are near impossible to detect, but have very low impulse speeds, they are favoured as 'silent running' engines, allowing the ship to move at a steady space, with some degree of agility, with a near zero detection ability, because they eject a small cloud of chilled ions, rendering them invisible against background thermal temperature and are too small of a RADAR to detect, effectively.
==Armour==
The armour is coated in a laminated shell of insulators to protect the ship during re-entry and provides crude ablative defence against energy weapons. Underneath this is RADAR/LIDAR absorbent materials, liquid glass resin, which provides protection against radiation and renders it UV invisible and 'black body' Infra-red paint then the primary composite hull made up of a layer of titanium for ballistic defence and ablative energy weapon defence. Along with this, layers of AEGIS tiles shatter ballistic weapons and provide ablative energy defence. Underneath this layers of thermal energy absorbing layers and kinetic absorbing layers. This forms 1 meter of plating. This whole plate is bound to pockets of non-Newtonian shock absorbing materials which absorb and diffuse the impact, protecting the ship's internal structure. Underneath is an aerogel layer that absorbs spalling and dissipates both background radiation and radiation does of up to 178 kilograys from directed energy weapons and nuclear fallout. Beneath this is a layer of foam that is secured in an air tight layer. When exposed to air through a hull breach it expands rapidly and fills the breach, providing it is small, making the ship air tight once again, if only for a time.
The entire internal superstructure is made of AEGIS-Titanium-A composite spars with non-Newtonian shock improvement, with a smaller sub-structure made of composite spars, that serve to increase the structural integrity and resistance to damage, compartmentalizing much of the internal structure, meaning the ship can take much more severe damage without losing critical functionality. This construction method, devised from the Halcyon-class Cruiser, proved invaluable to the survival of the small ship, and was copied for much larger cruisers and carriers. The ship is rigid enough to survive critical impacts from kinetic energy weapons but can flex without causing stress fractures during orbital re-entry.
==Shielding==
The Heimdall-class uses a Corinth Mark VI Projected Energy Defence System, made by Katakes-Robinson Company. This robust shield generator, of Grade 3 standard, allows it to stand against covenant vessels of similar tonnage in combat. It can resist a single MAC round, three plasma lances, and numerous blasts from pulse lasers, Necros weapons or missiles of varying kinds, and can directly resist both a nuclear warhead of similar power to the AVENGER or an energy projector hit. The strain on the reactor is actually surprisingly minimalistic, though recharging it requires significant power. Power can be redirected from other systems to charge it or reinforce it, the emergency fusion power plants or the 4 CV-5 magnetohydrodynamic turbines which can generate 30 to 40 megawatts each. Recharge time, as standard, is around about 1 minute without enemy fire to begin recharging, with it recharging in about 2.25 minutes. The energy shielding is projected across the whole hull but drops to allow fighters and ordnance to leave and exhaust gasses from the engine. Should a section be damaged, the local shield transmitter may no longer be able to project shielding to that section.
With the Project VULCAN updates, the shielding emitters were reprogrammed into cyclic shielding, offering greater protection and recharge times. Hooked up to the ship was two AURA Module hooked up in series, allowing it to sustain much more damage for longer periods, allowing the ship to have much more endurance in combat situations.
==Computer Systems==
Computer systems on the Heimdall-class were focused around internal servers with triple redundant armoured internal hardlines connecting to outward computers. While most the computers were EMP hardened, they are only ruggedized solid state electronics. The servers however, are EMP shielded liquid state electronics with armoured matrices. Every computer network (reactor, rocket motors, each weapon phalanx, each archer pod, each turret, each shielding emitter, each sensosrs and countermeasure, all run off multiple computers, linked to a single server. From here the servers are linked to the main A.I., which remains in the A.I. core, deep in the armoured gut of the warship. The A.I. core houses the Artificial Intelligence, four sub servers and numerous data stacks and computer systems, boosting the A.I.'s performance exponentially, though the A.I. can be plugged in anywhere on the ship. The whole entire room is super cooled to maintain operating capacity and each system contains independent cooling systems and anti-fire systems. Every computer system in the A.I. core, including the room itself, is EMP hardened, and the liquid state electronics with crystalline cores are highly protected against EMP effects. The entire ship can be rebooted in five minutes, while a individually system can be rebooted in two minutes, meaning EMP effects are short lived. Also housed in the main core is the NavCom core and other vital computer systems, such as the main ADIS server and other vital computer components.
Very few systems on the ship used wireless and retain use of high speed hardlines inside the ship, to protect against potential cyber infiltration. However, should the ship be infiltrated, the A.I. is in full command of a array of servers, allowing it to preform simple brute force back hacks, which are highly effective, or can cut off the afflicted system from the server, or cut off the server from the core, then manually purge the system and reboot it in under two minutes from back ups in the core. The entire core can be manually removing server shielding, disabling fire fighting systems and detonating a internally designed high power plasma charge inside the room, designed to cause only localised damage, melting the servers and other systems beyond use, which, using command coding from either the A.I. or any high ranking ship officer, can be completed in 90 seconds.
==Sensors and Countermeasures==
The Heimdall-class uses an array of sensor systems, mostly mounted on forward pylons. These are aimed away from the ship so its bulk does not interfere with them. It has a AN/SVS-68 Optical Telescope and a AN/SAS-67 Infra-red Telescope, with twelve meter apertures, Optical and spectrographic information from these are supported by a *AN/SPY-7 PAVE SAW Radio Telescope array, which acts a high power, forward directed Active Electronically Scanned Array RADAR, with 130,000 steerable transmitters, and this is then supplemented by a secondary AN/SSS-19 SAFEGUARD Electromagnetic Array for passive monitoring of the electromagnetic spectrum, which allows to them to monitor electromagnetic activity in the forward area, allowing them to detect RADAR emissions, communication systems and radiation spikes from energy weapons and slipspace travel. The forward RADAR array is supported by 4 AN/SPY-9 PAVE HOUND Active Electronically Scanned Array RADARs positioned strategically around the hull to provide 360 views of the ship. These RADAR systems can detect 0.5m2 objects at distances of 5000 km and 50m2 objects at 90,000km and it can detect 0.5m2 objects at distances of 11,000 km and 50m2 objects at 170,000km in the forward arc from the forward radio telescope. Numerous AN/SLS-12 HORNET Light Detection And Ranging also cover the ship, providing a accurate threat identification system. Along with this, the ship has several dozen AN/SSQ-23 Sensor Network installations across the hull, made up of smaller optical/infra-red sensors across its surface. Each of the weapon positions carry their own sensory network with optical, infra-red, LIDAR and millimetre RADAR. As a final protection, the Heimdall has a second, smaller Electromagnetic antennae to observe changes in the electromagnetic spectrum to it's rear.
As part of Project VULCAN, all on-board RADAR systems were fitted with Sidovoritch Apparatus, which comprises of a phased particle bay, that triples frequency speed of RADAR systems, allowing them to detect targets in a much shorter time.
The Heimdall-class has numerous countermeasure systems, allowing it to defeat numerous enemy weapon systems. The AN/SLQ-340 PIRATE Torpedo counter guidance system can redirect enemy plasma torpedoes by interrupting and interfering with their magnetic guidance systems with four magnetic signal systems, forcing the weapon away from its intended target. It has limited effectiveness on Lance weapons as well. This system increase the ship's survivability against Covenant warships. The HARLEQUIN Decoy Launcher launches ballutes are balloons made from tough materials powered by a minimal electrical Power Plant. Due to a lack of any stealth features, they resemble its parent ship on RADAR and optically, causing confusion with enemy gunners. These can be launched to cover the ship, seemingly increase the numbers of attacking forces or deflecting attacks away from it. The AN/SLQ-301 'PAVE KEEPER' is a protective Electronic Warfare system that consists of a RADAR receiver for detecting enemy RADAR systems (ship, single ship and missiles), a active jammer system and a number of decoy launchers. In addition, the PAVE KEEPER system contains a number of low intensity LASERS, designed to blind optical and infra-red systems and confuse LASER guided systems into rebounding upon the launcher. The PK is linked directly to the ship's on-board sensors to provide the ability to launch decoys to protect the ship from missile or weapon locks. The Pave Keeper system has access to a number of decoy dispensers, linked up to seven dispensers across the ship, with each system using three barrels which can be independently loaded and fired and are mounted on a turret giving them strategic launch capacities to cover multiple attack angles. The launchers can be fed with a variety of rounds, allowing an individual ship to be fitted with mission specific load outs. Decoys are powered by internally carried rocket motors, allowing it to be ejected from the ship at high speeds and manoeuvre away from the ship. Decoy load outs include 
*High power Infra-red flares, designed to blind infra-red, ultra-violet and night vision systems with high intensity lights, with variable 'dial' settings controlled by ADIS and AI parameters to adjust it's brightness and intensity in various spectrums, to allow to to match vehicle signatures or to simply blind targets.
*Ion flares, producing strong electromagnetic fields, capable of generating false signals on magnetic detection systems, confusing magnetic guidance system such as MAD guided missiles or magnetic tunnel guided munitions such as plasma launcher munitions. The variable settings on Ion Flares allow them to either produce a wide band jamming signal or producing false signals.
*Smoke generators, producing a non-toxic smoke. The smoke mixture has a number of high energy particles mixed in, which when ignited generate a high thermal signature across the entire smoke cloud, which can cover up to five kilometres, creating a thermal 'blotch', wherein ships can safely hide.
*RB-3 aerosol composites that disperse in a prearranged cloud detonation to diffract DEWs with a 79% effectiveness.
*Chaff dispensers, which confuse RADAR guidance and detection systems within a wide area around the vehicle. These utilise a wide variety of alluminium composite strips, designed to cause massive interference over a wideband, with more narrowband optional flares to create a protective blanket that does not blind their own RADARS.
*AN/ULQ-499 Variable Mission Programmable Radio Decoy (VAMPR, more commonly referred to as 'VAMPIRE') is a multi-purpose radio decoy, with a number of capabilities that can be programmed by the ADIS or AI before launch. The VAMPR is capable of emitting spoofing signals, beam false co-ordinates to the RADAR seeker of the missile or opposing fighter, producing a wide range of false signals matching the launch platform to confuse missiles with false RADAR targets, wide ban jamming or narrow ban jamming or simply blinding RADAR guided ordnance.
*RM-11 composite dispersal is a specialised dispersal pod that covers an area in a dense field of titanium dust. This dust has a high effect against plasma munitions, causing premature detonation and reduction of munition density, causing plasma munitions to lose their power against the target. 
The Heimdall also carries a AN/SLQ-221 DOPPLEGANGER Array. This is a AESA RADAR system carried in a towed array on a 7000 metre long nanotube composite cable. This array has it's own independent ion thruster array, decoy launchers and point defence LASERs. The purpose of the array is to provide a RADAR without subjecting the ship itself to immediate harm, but it can also act as a RADAR receiver and jamming system, providing narrow band and wide band jamming and provide false RADAR information, jamming enemy RADAR, MASER and Radio signals by cancelling out their signals. This is controlled by the ship board A.I. back hacking their communications and adjusting it to their wavelength. The DOPPLEGANGER provides all round RADAR views by getting it a suitable distance from the bulk of the ship. It sports a number of AN/SLQ-1011 PAVE FAITH emitters, which are high power active cancellation pods, allowing the warship to actively disable enemy RADAR systems, rendering enemy systems blind. Through the on-board A.I., it can actively avoid enemy countermeasures and adapt to frequency hopping. It's final and most basic defence is the 17 Emergency Thrusters, which are placed strategically on the ship, to provide sudden motion to the ship's trajectory. They consist of strategically placed tanks on the ship's outer hull, containing trihydride tetrazene and hydrogen peroxide. When mixed, they cause a explosive reaction that violently change the ship course. When struck by an attack, they are designed to explode away from a the hull, to the sides, not seriously effecting the ship's course or hull.
==Systems==
*Shaw-Fujikawa Model 52
::The newest model Shaw Fujikawa slipspace drive uses a particle accelerator derived from Covenant systems to minutely create and control a black hole in time space, cutting a hole in into slipstream space. The process is much more elegant, with sling particle drives assisting it by sustain the hole and enlarging it. This allows UNSC vessels to create accurate and and safe 'gates' without excessive force, meaning the newer drives take less time to charge. The drive is capable of going to similar speeds of Covenant and USR drives. The drive is protected by intense anti gravity shielding, allowing it to cut holes in gravitational fields.
::The MAZE system is a slip space directional router, basically a AI guided Slipspace guidance system. Though it can operate autonomously it requires a AI to observe its actions and ensure it makes no mistakes, if only for peace of mind. It got identify and follow various 'eddies' and 'strings', being capable of accurately avoiding any hazards or potential elements that may slow down the journey.
*AI/Manual driven computer supported pilot systems
::The Drive system focuses on either a manual, manual AI assisted or AI solo drive system either through neural interface of manual controls on the ships rather rudimentary pilot system, making use of joysticks. These filter through to the vectored nozzles on the ships engines, and while on manoeuvres, only the manoeuvring rockets are used, though the primary rockets can be used. Also, they have access to the use of emergency boosters, though the AI can override this if necessary.
*AI Assisted ADIS
::The Area Defence and Interception System protects the ship from harm across its immediate area by directing point defence systems. Firestorm Close-in Weapon System provide the primary interception system with the dual THOR lasers being arranged in phalanxes of five, with the first three being the main interception lasers and the rear line two being 'over watch' engaging any targets that slip past. These are supported by a M980 Weapon Anti Ordnance/Anti Material Defence Weapon secondary turret on every turret that engages any incoming missiles. Furthermore these are supported by a phalanx of two Thunderstorm Close-in Weapon System that annihilates enemy fighters evading lasers through various means or providing a minefield, at the command of the AI. These are all guided through the close range Phased Array RADARs, optical systems, primary RADOME and radio scanner systems. It can identify and engage up to 600 targets. Up to 1000 with AI assistance.
*Communications
**MASER Dish
**Slipspace carrier wave projector
**PROXIMA System
::UNSC vessels user MASER dishes, a dish that sends out coded microwaves that provide near instant intra-system communication. These allow ships to remain in contact. As a back up, they contain a PROXIMA system, consisting of a radio antennae and several microwave relays that can both pick up and send information across a short range and communicate with ground forces. UNSC vessels also have the power to launch accurate carrier waves through slipspace by making a minuscule hole in slipspace and projecting encoded light emissions through them. These are picked up and decoded by listening posts that relay the messages to the intended destination.
*War Net Integrated computer
::The War Net provides a total analysis of the battlefield and linked targeting information and combat details through encoded radio and MASER transmissions. This links all warships in combat, From single man fighters to might Dreadnoughts.
*High Orbit Precision Entry Vehicle Launcher
::These are the successors to the HEVs and are design to give marines a fast, stealth and safe method of aerial entry. These can be fired from low orbit or even from within a planets atmosphere. These are kept on one corridor, with ten loaded. These are further fed from a magazine of three more for every position. These are kept in place by magnetic locks. They feature vectored thrust rockets to allow direction on attitude, guided by the occupant, coolant jets, stealth features, a shield and a gravitational support field. This ensures massive survival rates of users.
*Anti-Gravity field
::The Anti-Gravity field provides the ability for the ship to manoeuvre in gravitational fields, such as in the atmosphere of planets. Developed from older, rudimentary systems of 2552, developed from gravity plating. The newer system uses various emitters to provide a buoyant and stable anti-gravity field around the ship, enabling it to remain level and nimble even in atmospheric conditions. These gravity systems are triple redundant and have the ability to be actively tuned, allowing the ship board A.I. to mask the ship's gravimetric presence or actively jam sensors designed to detect objects in deep space using gravimetric distortions in space time. This was fielded to defeat late Remnant War vessels crudely equipped with slavaged Forerunner Spacetime sensors.
==Capabilities==
The Heimdall-class Frigate is a extremely capable and adaptable warship, being capable of performing main line warship duties, patrols, escorts, planetary invasions and hit and run. The ship is tough, readily available, fast, well armoured and well armed, being capable of destroying much larger ships in packs and capable of fending off swathes of fighters with its own defence systems and its fighter capacity. It can also commit to planetary invasions, being one of the few UNSC classes capable of planetary landings. It can land and deploy war machines and marines directly to the surface while also delivering air vehicles. Due to its cheap production costs and its easy construction, it is one of the most seen UNSC warships as well.
==Construction==
The ship is extremely simple and easy to construct, with many shipyards across the UNSC being capable of constructing the ship due to its simplicity and ease of design. The ship can be laid down in just under six months at normal work pace though at war time it is possible to decrease this to 3 months.
The ship is built simply, mostly around a heavy yet flexible frame of solid titanium-b. This is incredibly hardy and is coated in heat resistant materials and, if need be, cryogenically cooled. This means while it has some flex, it does not expand or distort, especially on reentry, meaning the ship does not tear itself apart or steadily become more unstable. From this point the ship is built up from the back, with the reactors going in first then the internal corridors before the nuclear launch bay and the MAC are finally loaded. The observation deck is added at this point as it is a separate and independent section, not part of the ships main frame. The ship is 'skinned' then 'armoured' before the missile and point defence weapons are added. The engines are inserted and the ship painted, before external tech systems are added and the ship is loaded. At this point, the ship is combat ready.
==Complement==
The Heimdall-class carries a hefty complement of both troops and vehicles, allowing it to carry a Marine Assault Unit in combat or can alternatively carry a Orbital Drop Shock Trooper Expeditionary Unit or Ranger Expeditionary Unit
===Marine Assault Unit===
====Ground Combat Element====
The GCE consists of an reduced infantry battalion with 3 companies reinforced, a combat engineer platoon, a tank platoon with 4 M820A Scorpion Main Battle Tanks, a reconnaissance platoon and a light recon platoon with Warthog and Mongoose vehicles
====Air Combat Element====
The ACE consists of a light VTOL attack squadron with 12 AV-14B Super Hornets, and a air/starlift squadron of 6 D-79I Pelicans and a support squadron of 2 MD-79L Gannet dropships.
====Logistic Combat Element====
The logistic element consists of a platoon sized force who can issue logistics command and control orders to ACE and GCE forces.
====Command Element====
The Command element provides command, intelligence gathering, electronic warfare and defence, an ANGLICO unit of a single Fire Control Team and communications unit.
===ODST Expeditionary Unit===
====Ground Combat Element====
The GCE consists of an reduced infantry battalion with 2 ODST companies ready for immediately HOPE drop and then a company readied for orbital insertion via Pelicans, a combat engineer platoon and a reconnaissance/pathfinder platoon.
====Air Combat Element====
The ACE consists of 2 air/starlift squadrons of 6 D-79I Pelicans and 2 support squadrons of 2 MD-79L Gannet dropships each.
====Logistic Combat Element====
The logistic element consists of a platoon sized force who can issue logistics command and control orders to ACE and GCE forces.
====Command Element====
The Command element provides command, intelligence gathering, electronic warfare and defence, a ANGLICO unit of a single Fire Control Team and communications unit.
===Ranger Expeditionary Unit===
====Ground Combat Element====
The GCE consists of an reduced infantry battalion with 3 Ranger companys ready for immediate orbital insertion via Pelicans, a combat engineer platoon and a reconnaissance/pathfinder platoon.
====Air Combat Element====
The ACE consists of 2 air/starlift squadrons of 6 D-77I Pelicans and 2 support squadron of 2 MD-79L Gannet dropships each.
====Logistic Combat Element====
The logistic element consists of a platoon sized force who can issue logistics command and control orders to ACE and GCE forces.
====Command Element====
The Command element provides command, intelligence gathering, electronic warfare and defence, a ANGLICO unit of a single Fire Control Team and communications unit.
===Space Combat Element===
*3 RQ-145 Perceptor are kept in a specialized launcher to give the ship recon abilities
*12 Katana superiority fighters are stored on the 12 launch bays on the ship, giving it effective fighter support in combat situations.
*10 Scimitar UCAVs are stored in the aft section and used for reconnaissance by force and support of other units, or even suicidal decoy attacks.
==Operational History==
The first Heimdall-class frigate, the UNSC Heimdall, went into operation with the 'long range patrols' around Kanna, escorting a refitted Pheonix-class Colony ship (now the Phoenix-class Cruiser-Carrier), the UNSC Kaliningrad, outfitted for long distance in-system patrols. They encountered a squadron of frigates in dispersed formation, and the UNSC Heimdall destroyed one and crippled another in a exchange of fire with out taking any return damage, its shields holding against their pulse lasers. This event was later televised, first system-wide and then UEG-wide. The Heimdall became a symbol of the new UNSC and prior to rearmament it was seen as one of the biggest technological leaps made in years. Soon frigates were being pulled off the line to be refitted or replaced, with 25 being produced in the first year and that figure doubling the next and remaining at a constant since then. Soon the Heimdall-class replaced every type of older frigate design, and its sister design, the Loki, replaced the Shadow-class frigate. Soon, the whole fleet was being replaced with ships borne from the Heimdall. Heimdalls continued to see service through the revival of the Remnant, being a reminder of how powerful the UNSC had grown to the Brutes, and then into the Necros War. Despite being often outnumbered and outgunned by the Legion-class Frigate, they remained in superiority through the use of better tactics and agility.
==Variants==
The Ronin-class frigate was a variant of the Heimdall. The hull was heavily modified to give it stealth features and was outfitted with stealth systems, both internally and externally, allowing it to operate as a ambushing warship and ferry for black ops teams.
==UNSC Comments==
"I served for four years on the Heimdall; before that, I served on the Marathon-class UNSC Defender. Nothing feels better than to have something between you, the armour and the plasma."
"Finally, frigates aren't throw-away ships; they can make a stand against Remnant or Pirate vessels of the same tonnage!"
"I watched a lotta ships get crippled or destroyed by a single hit from a Covenant vessel. That ain't gonna happen as much now!"
==Ships of the line==
===Block 1===
Block '1' was the 'proof of concept' and limited to just 14 warships
*UNSC Heimdall (Class namesake)
*UNSC Red Tide
*UNSC Nerves of Steel
*UNSC Northumbria
*UNSC Sol
*UNSC Brawler
*UNSC Dragoon
*UNSC Black Guard
*UNSC Last Order
*UNSC Sefirosu
*UNSC Aeris
*UNSC Strife
*UNSC Santini
*UNSC Lightning
===Block 2===
Block '2' was the green light for full production of the concept model, expanding the production to 43 ships
*UNSC Mothra
*UNSC Battra
*UNSC Serizawa
*UNSC Tanaka
*UNSC Revenge
*UNSC Fitzgerald
*UNSC Omaha
*UNSC Utah
*UNSC Juno
*UNSC Golden Sword
*UNSC Point Du Hoc
*UNSC Kiwi
===Block 3===
Block '3' was the first block that replaced decommissioned or destroyed warships that had been struck from the naval register
===Block 4===
Block '4', which were created at the same time as Block 3, upgraded older Frigate hulls to the abilities of the Heimdall.
===Block 5===
Block '5' was the first casualties replacement, refitting and replacing ships lost during the first six years of the Heimdall's existence.
===Block 6===
Block '6' was a minor correction of a problem encountered with six of the forward ion thrusters
===Block 7===
Block '7' was a attempt at modifying the hull, plating and other systems to create a stealth frigate, like older warship designs such as the . This later became designated the 'Ronin'.
===Block 8===
Block '8' introduced the Ion Cannon as the Warship's main armament, giving the warship a powerful directed energy weapon with potent electro-magnetic after affects. This block became the Prometheus sub-class.
===Block 9===
Block '9' featured upgraded atmospheric capabilities, giving it high agility in atmospheric conditions.
===Block 10===
Block '10' featured a number of incremental power increases to the engine and shield generation systems. Block '10' became the most manufactured block of the Necros War, still being constructed up until the final days.
===Block 11 (Prometheus-class)===
Block '11' was a Refit of damaged classes to fit more Ion cannons, which were in increasing demand, changing the ships to Prometheus-class vessels.
===Block 12===
Block '12' fitted a single RETALIATION MIRV in place of its usual nuclear payload
===Block 13===
Block '13' was a number of damaged ships, that were refitted with extensive communication and control systems, designed for small unit flotilla combat, though few saw frontline service, with more being reserved for patrols.
Category:Frigate classes
Category:UNSC Ship Classes