Nevada-class heavy frigate

"For more than two decades, the UNSC Navy has been smashed into the ground, with none of their ships capable of taking on their own equivalents without severe losses. Here at SinoViet, we believe that time has long since past - our engineers are set on creating the next-generation of warships; faster, stronger, better in every way. And to prove it, we will now reveal a ship that can take on a Covenant vessel three times it's size. Humanity, your time hiding beneath your sheets is over."

- SinoViet marketing spokesperson, unveiling the Nevada-class frigate.

The Nevada-class heavy frigate (: FFG) is a heavy general-purpose escort and combat vessel that was utilised by the  in the immediate aftermath of the. One of dozens of new designs created during and after the war to supplement and replace the UNSC's battered fleet of frigates and destroyers, the Nevada is the largest and most powerful frigate ever built by the UNSC. It represents a considerable shift from the previous design philosophy, trading cost-efficiency and some adaptability for superior combat capabilities and more advanced technologies. Despite this, the Nevada still retains the traditional shape of its predecessors, and can still be counted on as a reliable 'jack of all trades' frigate.

The Nevada-class was introduced in, with it's development accelerated after the Fall of Paris IV. Being a test-bed for a number of experimental technologies, the Nevada saw limited service as it's complicated frame and untested subsystems saw questions arise about it's reliability. Despite participating in a small number of battles before their commissioning, the Nevada only saw action in numbers during the in which the class took heavy casualties. Despite this, the frigates' proven potential would see development continue until finally the class was approved for mass-production after the.

Layout
The Nevada maintains the traditional frigate shape, maintaining the winged engines, twin armoured bow pylons and an underslug troop bay present on nearly all frigate classes since the. However, it does not go so far as to adopt the stripped-down design of its predecessors, instead adopting a bulkier, more monolithic profile with fewer weaknesses in it's superstructure to maximise structural integrity.

The bow is characterised by the split boons, with the top housing the MACs, forward Archer missile pods and most of the side ion manoeuvring engines, and the bottom containing the crew quarters, most of the vital sensors and communications arrays, and the primary life-support subsystems. The split isn't particularly pronounced on this ship, with the superstructure connecting both with the first fifty metres. It is at the front of this connection where the primary bridge is located, with two docking ports on each side. It's unusually-small and not very pronounced for a UNSC ship; a trick done to make it look like an observation deck, ensuring that incoming bombers will be more likely to assault further down the frigate where most other classes have their bridges and Combat Information Centres (CIC). Should it be attacked, there are two retractable point-defence guns which can shoot down incoming munitions and a miniature shield generator to protect it. Less than a dozen of the ship's officers man the cramped bridge, with their stations located on the sides and back. The captain resides in a command chair at the front surrounded by touchscreens which can bring up any information he desires. Unfortunately, the Nevada 's bridge has come under scrutiny by their crews for two reasons. Firstly, the docking ports located right behind the bridge have been identified as a weak point, potentially allowing a boarding party to easily capture the bridge with minimal resistance. Secondly, the crew must take an elevator up several levels to reach the closest escape pods, affecting their chances of survival. An emergency internally-mounted CIC is installed at the back, just forward of the engine wings.

Flanking just behind the bridge are the two hangar modules, which are protected by six raised M37 "Suppressor" naval coilguns, three on the top and bottom. These are the frigate's primary broadsiding elements, capable of firing 30-centimetre slugs at both a high firerate and velocity. In between the hangar bay doors are four M910 "Rampart" point-defence guns. Optimised for high rate-of-fire, these turrets are capable of dynamically switching between sub-calibre 50mm rounds for smaller threats such as fighters and missiles and 105mm anti-fighter, covering the launch of the ship's complement from any threat possible. The fore of these sections contained a single fusion drive, directed downwards to support the frigate's weight in atmospheric conditions or give inspired captains more opportunities with manoeuvring. Behind these are five hangar doors adapted from it's predecessors, all well-armoured against even heavy anti-ship munitions. However, these doors are only large enough to accommodate aircraft smaller than the, so in spite of the module's size it can only carry smaller aircraft such as and. Because of this, a subclass had to be developed with hangars wide enough to accommodate. The section which connects the lateral pods to the main body also contain the frigate's heavy missile complement, powerful enough to threaten even Covenant ships almost three times its size.

Towards the end of the top boon, and only featured on post-war frigates, is the circular shield generator, custom-built for the frigate's needs. Unlike those on the, these are activated upon detection of any enemy vessels rather than impacts to the hull, providing superior protection for the frigate. Power is not an issue as it is powered directly by the frigate's secondary behind them, reinforced to protect it from incoming fire. Resting on top of it is the main MASER communications array and an observation deck, both of which were ripped off from a Paris-class frigate to streamline production costs. On the other side is the ship's barracks, which hold the living quarters and cryotube bays for the Nevada 's and  teams. A small elevator only holds four for reconnaissance duties is added on the bottom, with the front housing two acceleration tubes for the. This entire section can be completely removed when operating exclusively in escort duties, minimising it's target profile and cutting off unnecessary weight.

Unlike modern frigate classes, the Nevada still retains the two engine modules flanking it's central aft section, inspiring fears that it could be easily rendered immobile through coordinated fire. In practice, such a weakness rarely reveals itself as weapons that can effortlessly cut through it's tougher armour will spread much worse impacts across it's hull. The advantages of this layout means that the frigate can be outfitted with the engine components from any other SinoViet frigate in an emergency, as well as limiting time spent at drydocks for maintenance. A high-tolerance RADAR antenna is mounted at the back, designed to filter out radiation from it's engines to detect any trailing craft. Right before it are two more M910 naval coilguns to protect it's flank, and the wings have hardpoints to mount sixteen additional Archer missile pods. Both of these immediately address the key weakness of the, in that the Nevada can be a threat from nearly all angles whereas the Strident has a massive weapons blind-spot on it's belly and aft. On the wings were it's two primary fusion reactors, hidden within a greatly-reduced section thanks to the removal of many missiles and other systems onto the frigate's main body. Unlike previous frigate designs, these have powerful fusion drives on both their front and back, with the front ones being conventional models while the aft have a curious bracing further back from their main exhausts. This bracing ensures the installation of an acceleration field to make older fusion drives more powerful, or hold a latent stabilisation field to suppress the effects of reversed-engineered derived from salvaged Covenant warships. Because of the engines' small size, the protective armour shields are much smaller than it's predecessors, and are angled to offer more protection in broadside fights.

Armament
The Nevada-class frigate is among the most powerful frigates ever built by the UNSC, combining a large array of cutting-edge technology with tried-and-true weapon systems. The strongest weapon in it's arsenal is it's main Mark IV heavy-coil. The Mark IV hails from the same family as the 56A2D4/MAC used on the, using magnetic-field recyclers, booster capacitors and more efficient components to recapture the energy used during the firing sequence. This allows the 220-metre long MAC to fire two 1170mm rounds in immediate succession, while decreasing the charging cooldown by up to twenty percent. These rounds were powerful enough to deplete the shields of a and deal moderate damage to the unprotected hull in a single salvo. Redundant coils are installed to reduce it's vulnerability to damage and sabotage or switch out overheated coils, leaving it's cooldown time dependent only on the reactor's output.

To back this up, five heavy missile pods are installed, usually carrying one hundred Howler missiles in total. Each pod has space for twenty individual munitions and can fire up to five at any given instant, meaning that they can only fire four volleys before needing to be reloaded. To make up for this, Howlers carry a large warhead that is very effective against both energy shielding and armoured hulls; only one hundred missiles are needed to destroy a. Their primary payload is a compressed ionic gas that is ignited into plasma upon impact, disrupting energy shields and have proved equally capable of burning through armour. A high-explosive charge detonates slightly afterwards to maximise the time to tunnel into the enemy where it can be most effective; this feature can be removed to cause large-scale destruction in ground campaigns. Because so few of these missiles are normally carried on UNSC ships, they are outfitted with a powerful drive system that rapidly accelerates them towards the target with only minimal manoeuvrability once their course is corrected. As they are more vulnerable to point-defence than traditional missiles, standard protocols call for them to be fired after a large swarm of Archer missiles to reduce the chance that they'll be shot down by the Covenant's.

Hull and superstructure
Unlike previous models of frigates, the Nevada-class frigate maintains a reasonably-thick and durable hull without a significant increase in mass. This is largely thanks to the Nevada adopting an 'all-or-nothing' principle in regards to it's armour, in which only the most important and vulnerable sections are given the thickest plates while others are protected only by. Coupled with a revised frame, this reduces the frigate's mass by almost 40% and significantly improves it's manoeuvrability.

El Salvador-class assault frigate
"The Nevada looked good, real good in simulations. But data can only take you so far. We knew at the time they wouldn't be enough to stem the tide of extinction. We needed more of them, and cheaper."

- Dr. Swarna MacCallum, on why the El Salvador was developed.

The El Salvador-class assault frigate was a much more heavily-armed variant of the basic Nevada-class frigate. Concerned that the advanced technologies would make it too difficult to construct and unreliable compared to the current generation of frigates, SinoViet engineers were brought in to strip out many of the mainline class' less necessary components, with only the impressive engine and reactor package being kept. Removing it's stealth systems and experimental Howler missile pods, the new frigate would instead replace these with thirty modular silos designed to accommodate. The single advanced MAC was replaced with two light-coil frigate MACs, and up to forty-eight M58 Archer missile pods were installed along with three. The lower winglet plating was straightened out and made larger to provide additional protection. Finally, the bottom barracks were greatly expanded upon, and could be detached to serve as a deployable fortress on enemy worlds. All these upgrades ensured that a fully-stocked El Salvador could carry far more firepower at a fraction of it's cost.

The El Salvador was released in while testing the UNSC Nevada was still undergoing testing, and would quickly be rushed into service.

Development
The concept for planning the next generation of frigates was first conceived within SinoViet around the start of the Human-Covenant War, when reports on the hellish casualty rates first reached the company. At first, their response was to accelerate the development of their, a light-weight warship originally contracted to screen the UNSC cruisers of the more deadly Covenant craft. While it performed superbly at it's intended role, it did nothing to stall the high rate of attrition of the frigates. So badly was it that SinoViet was forced to begin seriously working on the next-generation of frigates in, as humanity's loss would result in the destruction of the company and it's assets. It was administrated by Nice Admiral of  fame,  withthe development of the new frigate would again fall towards Doctor Gaurav Shankar, who was SinoViet's most experienced light-tonnage designer.

The design brief called for Shankar's team to design a warship that can destroy it's intended equivalent, the. It would be the successor of the, combining heavier firepower, improved durability and more advanced technology. The design team would immediately get to work, with early attempts looking at adapting existing frigates with experimental technology. Shankar would later describe the entire process as a 'shipwright's nightmare', between his superiors ordering the new ship to conform to existing SinoViet designs and Stanforth's reluctance to reveal the complete details on experimental components. Despite this, the team would rise to the challenge, eventually producing a design that borrowed heavily from the Paris-class frigate. Satisfying all departments, the lead ship would be laid down in, and after two years of testing, would be approved for production.

Trivia

 * The Nevada, like the and the, is an example of fan-made content that have been featured within official Halo comics and artwork, yet has not been officially canonised. It was originally made by calamitySi on Deviantart.