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A variant lacking the central pylon

Class overview

Mercury-class Destroyer


UNSC Logo TGW 2.png UNSC Navy
New CMA.png CMA
Rebel-Insurrectionist symbol.png United Rebel Front

Preceded by
Succeeded by

See Variants


48 (2526)

General characteristics



1,200 metres (3,937 ft)


288 metres (945 ft)


307 metres (1,007 ft)


5.19 million metric tons

Engine unit(s)

E-45 Mark II Deuterium fusion drives (7)

Slipspace Drive

Naoto Technologies' V14/SM6-SFTE

Power plant
  • F1n-342 fission reactors (3)
  • Pocket Reserve Generator Racks (3)
  • Naoto Technologies' V2/L-DFR fusion reactors (2) (Later replacements)


  • 1 metre of bonded Ceramic-Steel
  • 1.5 metres of Bismuth-impregnated Graphene armour (later addition)
Sensor systems
  • T-65 Enhanced Sensor Dome
  • M3 Non-Photon Motion Array
  • LADAR Class-I Backup
Navigation system

UNA-uplinked navigation computer (1)

  • Emergency Engines (5)

Initial armament:

  • PD-M677 missile-defence turrets (22)
  • R31 "Loki" EMP missiles (12 pods of 3 missiles)
  • Mark I cruiser-grade MAC (1)
  • F/A-13 Razors (1 squadron/12 aircraft)
  • MM6-TC Sparrows (12)
  • CMA marines (~350 men)

1,600 sailors

Additional information
  • Support Destroyer
  • Colonial Escort
  • Long-Range Scout and Patrol
  • Armed Courier

"A pity what happened to the CMA, I was starting to like their organisation. Sure, its based off what the UNSC had, but there was something that made it so... enjoyable to work at. I don't know what I'll miss the most - the frontier arrogance of my crew, or flying into deep-space in a heavy destroyer without knowing what I'll encounter next."
―Retired CMA Captain, who was assigned to the destroyer Indifference.

There are many reasons why spacers are anxious to travel past the border colonies - pirates, rogue asteroids and the dangers of travelling through uncharted space meant that few would ever think of voyaging past humanity's colonial borders. Occasionally, the desperate, ignorant or stupid would venture out here, trying to carve out new trade routes for fame or establish secret colonies on the fringes. Before and during the war, a single class of ship was usually the only thing which stood between life and death for those willing victims: the Mercury-class Destroyers.

Originally manufactured by Helios Weapons as a last-ditch effort to save themselves from bankruptcy, the Mercury-class Light Cruiser (hull classification symbol: CL, later changed to DDH), then known as the Georgian-class Civilian Courier, was originally designed as modular colony ship, but they soon found it had the potential for a heavy warship. Before they could get any profits off their design, economic pressures forced Helios to sell their assets to buyers, and the Mercury landed itself in SinoViet's hands. Under SinoViet's ownership and marketing strategy, the ships surged in popularity - its modular design, reliable technology and low selling price all contributed to its success. Though they fell out of the UNSC's favour about one and a half decades after they were first produced, they quickly found use with the CMA. It should be noted that, due to the Dormant-sponsored refitting project that occurred every five to ten years, the ships had a legendary service life - some ships were theorised to be over seventy years old by the time manufacturing ceased.

Uniquely, many crews hesitated about signing their forms to be reassigned. Many who served on them had good opinions on the class, though engineers would have fits upon discovering that they were placed aboard one of these. This is because that, thanks to the hundreds of independent refitting programs that were both legal and less so, there was a high chance that the next ship they were transferred to would be radically different to the original blueprints. On the other hand, the well-thought out interior design, right down to the flight console, made stations surprisingly easy to use, making them popular in their crews. That said, it was always impossible to say for sure which systems would be present on an individual Mercury.



While there are a huge number of unique variations, all but the most extensively modified destroyers of this class can be identified to a common design plan. They tend to have a long, thin profile, easily divided into two main sections: the forward command module, and the rear maintenance area. Linking the two sections is a series of hollow pylons - the number and size of the pylons differs from ship-to-ship. The pylons, found on only a few other vessels, are fitted with electro-magnets or docking claws to carry additional cargo and materials on the exterior surface, capable of holding far more than their relatively small cargo bay ever could. The aft section was normally the widest part, and this is where the heaviest missiles and munitions were fitted. An extended structure on the starboard side is where the bridge lies, though later models lacked this tower completely, incorporating it into the front of the ship, or even having both. Finally, almost every member of this class are all larger than the later Marathon-class cruiser - a feat unheard of for a cruiser at the time.

The most extreme modification available - a double-layered superstructure with twin engine sections

Of course, that's where all similarities end. Even the exterior 'design cue' can be surprisingly different from ship-to-ship; in fact, these differences means its often possible to guess when a particular ship was made. For example, if the ship's exterior is curved and aerodynamic (reminiscent of early twenty-first-century exo-atmospheric craft, such as the space shuttle), then it was part of the initial production group in the 2460's, while if it has a very boxy and angular design, it was produced in the last era of its production run - the 2500's and the 2510's. Between those dates the ships have a mix of these two aesthetic choices, though some have a few deviations where other styles were popular. Of course, the sheer amount of refits and modifications added often make it harder to see the original armour and guess its construction date. There is almost an unlimited variety of upgrades which can be added, ranging from thicker armour to a more complex 'bio-pylon' filled with plants and animals for trade. Even additional superstructure sections weren't rare, most of which usually resulted in a low-handing 'beard' placed under the forward section. The latter section was often necessary, since it featured additional weapon hardpoints, power generators and sometimes chemical engines helped bring the ships up to par with modern vessels, though these were only available as part of a very expensive refit few could afford.


Although often described as a 'piece of junk' by onlookers mocking its appearance, once they came aboard all but the most ignorant would be immediately surprised and shocked at the sudden change of care in the interior. Indeed, if there was one thing that made crewmen pause at their decision to change ships, it was the wonderful interior. A mixture of environmentally-sustainable materials and a minimalist arrangement was combined to give the general art style in the hallways. Unlike the heavily-greebled and disjointed design leaf later warships would adapt into their interiors, the smooth walls would only occasionally be broken by a control panel or bulkhead which would maintain a view that was neither busy nor boring to those who cared to look. When coupled with the cool colours and curved shapes carved into the walls, the interior emitted an airy feeling which also gave a sense of calmness to everyone onboard. In highly-populated places such as the mess halls, statues of either stone or wood would be present.


The reason why the interior was well-received by most was not because of the materials it used, the expensive nature of said materials (which was false), but because of the skill of the interior designer, Augustus Partchi. Partchi's initial concepts were so incredible he was immediately promoted to lead interior designer - something which made the rest of the team jealous of him. Their hostility and his inexperience at such a position meant that he limited his actions at invading their privacy, only dropping suggestions to improve the quality of work being produced while he worked on his assigned projects. He designed the layout of some of the ship controls himself - an arrangement which, while appearing cramped and lacking order to those without ship navigation training, was actually natural, simple and surprisingly easy to use for their pilots.

One area which was not so well received was the maintenance corridors for engineering personnel. A side effect of the minimalism artistic incorporation meant that thin plating too often covered a vital component which happened to be malfunctioning, a trade-off for visual appreciation. The ramps getting into the complex machinery was ill-considered and barely organised, with cramped spaces being obstructed by pipes making it harder to find what you're looking for and easier to get lost. Even worse, as time went on the core systems of many ships became much different than the blueprints suggested, making searching for different components all the more harder. It was here the veteran's saying "An engineer's paradise is never found, only made more frustrating as they change ships" originated, due to the arrangement becoming infamous among mechanics and striking fear upon learning they were being assigned to a Mercury.


In its primary role, the Mercury-class Destroyers were designed to function as cheap flagships of battlegroups, winning engagements by intimidating hostile pirates into surrendering. Arguably, their size was an advantage for this, as their length was second only to dedicated colony ships. When a pirate captain glanced upon it and compared their ship to it, it was believed that they would be convinced that their ship couldn't beat it. As Mercury's rarely fired a shot during their early deployment period, this made it hard for traitors of the UNSC to learn of its actual armament. Even if its size illusion failed and it was forced into a pitched fight, its dual-bridge design and reliable communications arrays allowed it to coordinate battlegroups with ease.

When Phoenix's were refitted into warships, they replaced the traditional Mercury as the de facto battlegroup flagship.

As the Insurrection picked up, Mercury's found themselves competing with the larger refitted Phoenix-class Support Vessels as the flagship of CMA battlegroups; they were eventually relegated to escort cruisers when operating with a Phoenix. This was because these lumbering titans were far better armoured and structurally supported than any of their smaller competitors, featuring more effective internal bracing and even an exterior composed almost exclusively of Titanium-A. Moreover, they were designed to oversee ground operations, giving they a powerful and adaptable communications systems which was easy to convert over to fleet management. In comparison, the Mercury boasted more powerful and responsive engines, superior sensor systems and at times slightly better firepower - strengths which were put to better use in a reconnaissance or escort role. Thus, many Mercury's were finally retired as battlegroup leaders to fulfill these new roles, although many still retained similar independence when patrolling the colonies by themselves.

Thanks to their adaptable hull design, Mercury's had found success in other areas. Some of the most powerful individuals, for example, could operate as heavy-hitters when other ships lacked the same punch or were too far away to help. They could also be used in less violent roles; when they had modular crates around their midsection, they could be used as a relief vessel, carrying food and supplies to highly-contested systems. Finally, when modified with stability cranes, extendible personnel transfer hallways and equipped with a variety of materials and power tools, these ships could operate as mobile repair platforms, arriving at the stricken vessel and given them enough system repairs to get them to the nearest planet.


Georgian-class Civilian Courier

A civilian transport that had a very similar silhouette to the Mercury's it spawned, Georgian-class couriers were unarmed, lightly-armoured civilian transports designed to ferry cargo across human space. It was designed by Helios Weapons, who wanted to break into the shipbuilding industry. Featuring large electromagnets to hold onto cargo in slipspace and a slightly more beefy design to better accommodate civilians, it had experienced minor popularity due to its size. To make the design profitable, Helios designed a newer model with a far more thicker central pylon which can hold even more civilians and cargo, and marketed it as a colonisation vessel in 2451 and a rival to the better-established Phoenix-class colony ship. However, the larger Phoenix's were already used across human space, and their more expansive interior space made it hard for the Georgian's to compete. By 2500, almost all members of the Georgian-class were destroyed or dismantled, having fallen out of favour for more traditional or practical vessels.

Mercury-II-class Heavy Destroyer

"I never understood why the CMA never brought the design on board. It could outgun anything smaller than a Halcyon and give a Marathon a good spar. Hey, I heard the UNSC Volkswagen even defeated a Covvie frigate - a ship half its size, mind you, but in terms of size proportion, no other ship could, no, can, perform a feat like that."
―Naval Officer Dephler, on the Mercury-II's capabilities.

In 2490, when steady drop in sales warned the Mercury line was beginning to fall out of favour with the CMA, SinoViet profit analysts determined that it would be healthier and cheaper to design a brand new starship to replace it, rather than continue to hire out drydocks to update the existing ships. Within six months of this decision, SinoViet released the Mercury-II Heavy Destroyer. At 730 metres it was over half the size of its predecessor but sported vastly improved armament and defensive systems. It still had the slender fore section and large and wide aft section, but that's where all similarities ended. The fore section was a long, boxy weapons platform dominated by its Mark-II Heavy MAC and the then-new Archer missile pods. The structure extended forward out at the bottom, where a number of point-defence turrets defended the built-in hangar. The wide aft, meanwhile, was stripped-down to the bare necessaries to fit the engine and power equipment, but little else. They were protected by three metres of Titanium-A armour plating, at parts improved with more armour mounted on shield-like structures on an arching design. To further support the design, a primitive system of parallel-crossing internal braces gave it superior protection at the time.

Though it was effective enough to be used in small numbers by the UNSC Navy, the CMA purchased only a handful of the Mercury-IIs after they tested the batch sent to them. Though the Mercury-II could outgun and out-fight the Mercury Destroyer no matter how it was outfitted, it suffered from three main design flaws that gave its predecessor a distinct advantage. Firstly, though it had far better combat applications and effective countermeasures, the bulky design of the Mercury-II was littered with weak points that were lacking armour, including its life support systems and the power distributors just below the main sensor array. Secondly, the interior was optimised for combat use, and lacked any cargo bays as numerous or as large as on the previous model - in fact, it could only carry 43% of the cargo capacity of its predecessor. Lastly, it was slower, had a less-sophisticated sensors and communication package and not as much space for consumables, making it not at all suited to investigating remote colonies or participating in reconnaissance missions deep in the frontier. Because of these flaws, the Mercury-II's ceased production in 2493, though some stored models were reactivated in 2526 to help with the fight against the Covenant. By then, their single-sided combat abilities which allowed them to win against a Covenant ship half their size meant that they were sought-after enough to use as escorts for fleet flagships, but not enough to press them back into production.

Mercury-III-class Cruiser

Beginning production in 2514, the Mercury-III was SinoViet's second serious attempt at replacing their aging fleet of Mercury Destroyers. Developed over the span of three years, a team of analysts researched their predecessors-to-be to inform the design team, incorporating almost every single advantage into its design which ended up being again slightly smaller than the Mercury. Once again inspired by the original build-plan, it had a flatter dagger-shaped fore section, a hollowed mid section regularly dotted with armoured doors and a massive, heavily-armoured aft section, along with the additional shield-like armour plating characteristic of current SinoViet ships. Two pylons, one on each side, had only one side connected to the aft section. Finally, a mounted bridge structure was mounted above the centre which could double as an oversized escape pod. It had a similar internal bracing system to its direct predecessor, the Mercury-II, but on a more limited level to further decrease costs.

The design brief was for an warship which could combine the strengths of both the Mercury and the Mercury-II, along with a focus on crew minimisation. As a result, this ship sported no less than two "Dumb" AIs, though it was more often paired with a single "Smart" AI instead. It was better-armed than even its last predecessor, with one Mark-II Heavy MAC, one frigate MAC, forty-eight Archer Missile pods and fifteen M910 point-defence guns, and was covered with a respectable three metres of Titanium-A armour. However, from the mid-section onwards was the key to its success. Its engines could only just match the E-45s on the previous models, and it could carry just as much if not more storage. The strange pylons were also an advantage; they were actually docking systems designed to hold onto a smaller ship while the crew could commence improvised battlefield repairs. Lastly, while they weren't as easy to modify, they did already have several hardpoints installed to allow for superstructure extensions. With all these benefits, the only thing the Mercury-III lacked was an affordable price tag, as it was proven to be twice the price of a Mercury-I. Despite this, CMA were satisfied enough to order a sizable amount of them.

Production ceased in 2525 when the CMA was effectively stripped of their budget and military force by the UNSC due to the arrival of the Covenant. Though they continued to be used by the UNSC in the war for survival, they would fail to be moved back into production. By 2552, nearly all examples of the Mercury-III cruisers were destroyed, as many of the colony worlds they were stationed at were attacked and glassed. A small number were constructed at the end of the war to act as massive scouts and long-range repair barges, but they were quickly replaced by newer and far more advanced starship designs.

Midnight-class Stealth Cruiser

Recusant-class Light Destroyer.jpg

As much a subclass as the Artemis-class battlecruiser was to the Marathon-class cruiser, the Midnight-class stealth cruiser was a nearly-unrecognisable variant which was used solely by the Wealthian Coalition. Created in the wave of unrest resulting from fear that a Covenant patrol could one day discover them, the Midnight at first glance appears to be a step-backwards with its even more skeletal design. However, this is considered a necessary compromise, as the Midnight's hull was built in such a way that it reflected sensor scans away from its hull, minimising detection. It was also faster and more maneuverable than the ship it spawned from, thanks to three of its main baffled engines being capable of moving along a single plane. Although it had a thicker average hull, this was limited along its upper section, leaving the lower parts unarmoured to reduce mass.

The Midnight-class was advanced even by post-war UNSC standards. It has two major innovations - directional shielding, and its main subatomic cannon. As the Wealthians never acquired shipwide shielding until after the war, they used a more primitive system which condensed it down to a limited area. The subatomic cannon, meanwhile, was a crude reverse-engineering of a Covenant plasma lance, making it less-powerful and shorter-ranged. To supplement it, two more efficient frigate-scale MACs are fitted, with a total of twenty-eight missile pods.



A close-up on the Engine arrangement.

The engine systems installed on the Mercury were very impressive for its time. Though dating years before the warship's conception, with upgrades they were capable of matching or outperforming systems on later ships, such as the Halcyon-class, an attempted replacement, and the Mercury-II, a failed successor. The E-45 Mark II-model Primary Engine Array was a condensed refinement of the old Mark I. While cheap enough to be used as the default engines, the Mark Is emitted heavy amounts of Gamma radiation from its fusion centre, which utilised a limited amount of nuclear fusion in its engine array to generate thrust. Additional drawbacks to that system was that it was notorious for its fuel inefficiency - the fusion occurred very fast and dispersed the fused Helium nuclei even quicker back out to space, pulling out unused deuterium ions with them as well. The E-45 Mark II was developed to solve these problems, and featured thicker anti-radiation armour to avoid killing their customers. A slight redesign in the Deuterium storage greatly increased fuel efficiency at the expense of a slight reduction in thrust power and Deuterium storage. Unfortunately, though it was possible to harvest power from these systems alone, many attempts to do so often resulted in a spectacular explosion within a handful of hours after the work is done.

While the seven E-45s gave the class its speed, the compact ME780 Propulsion Pods mounted on the sides gave the ships its limited maneuverability. The ME780 is a tap-like system which builds up pressure in its gas chamber before being released. This was highly fuel-efficient, and reduced the amount of fuel the ME780's needed to turn the vessel. They were often mocked for their reduced pushing power, however, and in extreme situations such as a collision course, captains often vented the internal atmosphere to supplement the propulsion pods - a horrible but necessary compromise.


Almost no ships of the class have the exact same weapons loadout. While most systems, such as the communications and engines are often kept on far longer than previously guessed thanks to their incredible reliability, the many refitting options means that its rare for the ship to keep the same weaponry throughout its life. Whenever its replacing its LOKI EMP Missile Pods with the ARES Heavy Missiles and finally to Archer Missile Pods, or the removal of its XMX-97 Heavy Deck Guns, there is no limitation of what weapons can be fitted on. Some private owners add even more lethal and questionable weaponry, such as railguns and, in the case of the Heaven and Hell, bioweapon warheads to kill off all human life and leaving ships and infrastructure intact.

Out of necessity, some wealthy owners of the Mercury-class fitted several pylons to their ships, to allow them to be more compatible with future systems.

With all this said, armaments require more than the barrel and ammunition in order to operate. The Mercury's unmodified power systems, for example, only produce enough power to just keep the ship's standard systems running. Not only that, but additional cargo areas to hold the extra ammunition and even extra cryosleep compartments must be added to crew and man the new weapons. These matters came to a head after Dormant worked with SinoViet to release a refitting program adding new MAC Coilgun infrastructure into the ship. This was the purpose of the underhanging pylons snapped onto the superstructure, mockingly called the 'Old Man's Beard' by servicemen. Among other things, the pylon provided extra cooling and power systems to power not only the exposed MAC sitting at the bottom, but also any other weapon array that the owner desires to add in the future.

With their ageless compatibility and limitless options to improve their hardware, in times of crisis such as the Insurrection, it can be correctly assumed that these ships were fitted with every type of weapon created up to that point, though in far smaller numbers when compared to other more modern warships. A list of known weapons fitted are listed below:


  • PD-M677 Missile Defence Turret - The original turrets installed on the original Mercury production group, these turrets were undersized PDG systems which, as their name suggested, were only used for countermeasures against missiles. Though not as efficient as missile jamming countermeasures, the M877's used less power to operate and were far cheaper to mass produce.
  • XMX-97 Heavy Deck Gun - XMX-97's manufacturers, Gryson & Sons Heavy Weapons, were the leaders of ship-to-ship weapons for more than twenty years. Easy to repair and upgrade, the XMX-series HDGs stayed in service right up until just before the Human-Covenant War, when the Mark 33 Spitfire took over their role.
  • M710 "Bulwark" Point-Defence Gun: The eldest member of the contemporary line of point-defence guns, the M710 Bulwark was first introduced in 2577 to provide a basic defence again incoming missiles and fighters. A rotatory cannon firing 30mm shells, M710s are still used on some vessels to allow it's later iterations to engage incoming strikecraft, having been upgraded to be compatible with modern computer networks.
  • M810 "Helix" Point-Defence Gun - The heaviest turret still using rotatory coilgun barrels, the M810 "Helix" was a pure anti-air turret that only fired 40mm rounds. Only slightly less durable than the newer M910s, M810s had the highest firerate for their class which allowed them to make up for their reduced stopping power. Although largely phased out by the more adaptable M870, their specialist design towards missiles and strikecraft means that this product is still actively supported by their manufacturers, with a select number of larger capital ships installing them to keep them safe from strikecraft.
  • M870 "Rampart" Point-Defence Gun - Introduced in 2490 alongside the ARES missile, the M870 "Rampart" was a revolutionary piece of hardware that finally allowed a single platform to fulfil all anti-missile, anti-air and anti-ship roles with a reliable computer operator, being smart enough to utilise different 50mm rounds for each individual targety. Despite their age, M870s are still commonly found on even post-War warships, famed for their rugged performance and the most affordable pricing in their class.
  • M910 "Rampart" Point-Defence Gun - The M910 PDG and its targeting system, introduced in 2513, was merely a revision over its predecessors, improving responsiveness, muzzle velocity, accuracy and durability at the cost of some firerate.


  • R31 LOKI EMP Missile Pods - As humanity's territory spread and overstretched the relatively-small UNSC and CMA navy, they sort every attempt to ensure that they would not be outmatched and condemned for their actions. This doctrine led to ship designers favoring the LOKI EMP missile pods as their main ship-to-ship weapons. While only carrying three missiles per pod, only a single pod was enough for even the largest rebel warship to lose power and be made ready for a boarding operation. These operations, however, led to increased loss of life as the pre-Insurrection 'bushfire wars' increased in frequency, eventually being phased out for more traditional high-explosive missiles.
  • ARES Missile - The massive ARES missiles are the closest missiles can get to Nuclear devastation in a high-explosive package. Though not a nuclear weapon, ARES missiles have such destructive capacity that only a tiny handful are ever fitted onto a warship.
  • FENRIS Nuclear Warhead - An aging design dating all the way from 2473, nuclear warheads weren't seen outside of UNSC hands due to the lack of trust they have with even their fellow organisation, the CMA. Packing a powerful punch and a sizable EMP radius, FENRIS were also used in cases of nuclear bombardments such as the bombing of Far Isle. By that time, however, more powerful warheads had come into production and the FENRIS was slated for decommissioning.
  • M42 ARCHER Missile Delivery System - The replacement of the ARES Missile came from the smaller and more economical ARCHER Missile Pods. Though ARES were undoubtedly powerful, they lacked the capacity to be carried in larger numbers which were useful in orbital engagements. In enough numbers, ARCHERs can cause as much devastation against a foe, and because of their large magazine size, they could dish out considerable firepower for a far more extended period. They became the standard UNSC and CMA missile in 2503.


  • Mark II Heavy MAC - A cruiser-type weapon only fitted onto ships the size of cruisers and larger, this weapon ran almost the length of the destroyer. Fitted with an internal magazine that is difficult to refill in combat, the Mark II can dish out heavy firepower at the cost of its slow firerate. While some cruisers such as the Marathon-class heavy cruiser were fitted with two of these, the Mercury didn't have the infrastructure or power requires to fit more. Their price means that few Mercury Destroyers sport these weapons.
  • Mark III MAC - A condensed version used on frigates, the Mark-III MAC was a common addition to most ships. Sporting a slightly quicker firerate, they were frequently mounted on the superstructure pylons at the front, complete with more than enough infrastructure to use them effectively.

Crew & Complement

Despite the skeletal size of the ship and the emphasis on automation, the crew complement was quite large when compared to far later vessels; on average 7,350 were needed to get the best performance from one of the ships. Although the advancements over its production run meant that number got slowly smaller over the decades, even by the 2510's it still needed 2,864 to run it - no small number by any measure. Most of those who were cut to decrease costs were gunners and the teams who maintained the weapon systems. To fit as many as humanly possible comfortably, a single Mercury-class had no more than eight massive Cryostorage chambers, each which ran lengthwise for more than a hundred metres.

Superstructure and Armour

One of the biggest aspects where costs were saved was in armour. While Titanium-A Battleplate began to rise to prominence when it was introduced, the Mercury relied exclusively on low-grade Ceramic-Steel alloy, which was far cheaper as it used easily-sourced Iron mixed with other elements to increase strength. While thick and substantially strong for its time, towards the end of its production run it proved to be useless against modern weapon systems such as MACs, which has been proven capable of punching right through the entire length of the ship and still carrying enough energy to cause significant damage to a trailing warship. Such a stunt, however, is extremely hard to replicate and thus is rarely pursued. Recent refitting programs, activated at the urging of the UNSC, disregarded replacing the armour altogether, instead overlaying Vanadium Steel over the top of the original armour. On occasion, some parts are overlaid with standard Titanium-A to protect vital components. Overall, however, very, very few ships of this class had any upgrades to their armour. To maximise its survival, the crews had to rely on its speed, rather than armour, to defeat opponents.

Likewise, the internal supports were reduced to save costs. Made from even weaker and cheaper TR Steel supports, they were laid down only when the interior components would fall apart in atmosphere. Because of this, despite its inferior super-structural supports, the destroyer was indeed rated for atmosphere. For these operations it required clamped-on manoeuvring pods to get it safely to and from ground, as its engines were too weak to support its weight in an atmospheric environment.


One of the most often upgraded components of the Mercury line was its reactors. In its original form, the power was generated from three F1n-342 Uranium nuclear fission reactors, two fore and one aft. Sustaining a combined output of less than 1% of what modern reactors could achieve, the F1n-342s were an antiquated and cheap system which used enriched Uranium rods stored within a molten salt solution, ensuring temperature stability. The heat is then filtered through to radiators which transfer it into a coolant which is then dispersed into space, recaptured at the end of the vessel. This antiquated system is vastly inferior to magnetically-cooled interior subsystems of modern vessels, as well as decreasing it's endurance in heavy combat operations.


Per standard, even on refits, one of the things which was rarely fitted was countermeasures - systems which could allow the ship to gain an advantage in combat. For those which has any, it is normally a missile pod which carries missiles with an unconventional payload, such as RADAR jammers and decoys to distract enemy weapons from heavier ordnance such as nukes. Any additional systems are rarely installed, as their power consumption overdoes what the generators are capable of producing, resulting in catastrophic software crashes as computing processors lose electricity.


Legitimate Service

The Georgian-class Cruiser, a militarised variant of original Georgian-class Civilian Courier, was unofficially put into production 16th October 2463. The first ship built was the Interceptor, a privateer ship used by the Private Military Contractor (PMC) company Unbreakable Security. As Helios originally wished to make it available to PMC companies, they kept its existence a secret by falsifying documents as a standard civilian courier. For the first three years of production, they had seven interested clients and orders placed for twenty-three ships. After the production of those ships, however, Helios made the stupid mistake of increasing prices by more than 20% in order to increase their profits. Almost no-one was interested. In 2466, SinoViet's agents were able to finally trace the sudden traffic of armed warships to Helios Weapons. In an act of a blackmail, SinoViet signed a contract with Helios to produce their remaining ships. In exchange, the incident would never be heard of again, and Helios can sell the SinoViet-manufactured ships.

It was never going to end well for Helios. Helios' ships never arrived until right at the end, at which SinoViet was able to sue them for illegal black-market trade. With no cash to spare, Helios couldn't oppose them. Forced to get rid of ships the economic way - by sending them on randomised slipspace vectors - Helios gave up all the rest of their company secrets to SinoViet. With an eye on making a good impression on the public eye, SinoViet made a vow to increase warship production to 'protect' citizens from 'rogue' warships. Several weeks of testing of the class was all that was required, and with some slight changes in the appearance to make it unrecognisable to the Georgian-class, renamed it as the Mercury-class Cruiser in an official military contract.

Fully knowing it would under perform when compared to any mainline cruiser, SinoViet offered it to the UNSC as an economical way to field cruisers while not having the price and upkeep of one. Unfortunately, the UNSC would ultimately reject it, citing that there was no scenario in which the new cruiser could perform over any others in service. Instead, the Colonial Military Administration (CMA) would adopt the ship into their fleets. A force comparable to the UNSC at the time, the CMA was responsible with protecting hundreds more colonies than the UNSC concerned themselves with. Although inferior in strength to the older Victoria-class armoured cruiser, it was less costly to field; five of the new Mercury cruisers could be built from the materials needed for only two Victorias, while needing only a fraction of the fuel and manpower to operate. The fact that it could operate in atmospheric conditions saw the Mercury being approved for mass-production; within a decade of service there were twice as many of the new cruisers as there were Victorias.

Ships of the Line

Name Hull Classification Symbol Commissioned Destroyed Notes
CMA Mercury CL-001 May 6, 2463 First vessel of the entire class, destroyed prior to the bombardment of Far Isle.
CMA Interceptor CL-002 First Georgian-class courier that completed refit.
CMA Independence Day CL-003
CMA Resolution CL-004
MSV Devil's Dance CL-005 Formerly christened as the UNSC Europa, now serves in the Glass Raiders.
CMA Condemnation
CMA Retribution
CMA Indifference
WNS Midnight Hour Flagship of the Wealthian Navy.
CMA Horseshoe Mounts Dedicated colonial escort, decommissioned at Mars in 2517
MSV What's in the Box? Civilian trading vessel, given to Insurrectionists of Kingston, recaptured in Operation: TREBUCHET.


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