Oróion Citadel

A bastion of might amongst the legion's armoured corps, the Oróion Citadel presents the adaptability and power of the First onto the battlefield ever since those halcyon days back on Terra. A superheavy among superheavies, the Oróion mounts weaponry best equated to those massive cannons Knight Houses employ, while providing support for those allies brave enough to roll into battle beside it. As the heavy guns and cannons obliterate their enemies the beast can easily repair and refit it's allied vehicles, all while under heavy fire. It is this combination that has seen the 1st Legion's armoured divisions simply roll over opposition, repairing the damage that does hit and shirking off the rest as if it was a gnat.

History
In the grand scale of the Legion's history there is little that match up to the particularly vicious campaigns they persecuted as a fledgling power during the Unification Wars. Terra was a vast and mighty place, and those barbaric warlords that had taken over during it's downfall had proven themselves worthy of their titles. In particular, the vicious Dracos of the Despot Dalmoth Kyn, master of Hy Brasil, raged against the golden enlightenment that the Emperor and his forces brought. It was on these rough plains, muddy forests and clustered hive cities that the Imperial Army and the 1st Legion first fought these great behemoths, and though little is left to remember the battle, the Legion bears a mark of respect to this day.

It seems that the voracious armoured elements of the Dracos had proven themselves worthy of the admiration of the tech-wrights of the First, for when the fighting was finished, many Citadel class tanks found their way into Imperial hands.

Though those battlefields are but a distant memory, and Hy Brasil another part in the glorious whole of the Imperium, the 1st Legion has seen to carry their ferocity to the stars with them. It is a shame then, that even the mighty 1st only have two of the mechanical behemoths left in their arsenal, the legion's particularly bloody origin before lord Araphel seeing many fall in an effort to secure victory. The remaining two are treated with great reverence and care, their systems and gears regularly maintained by legionary tech-wrights, keeping the gargantuan beast well serviced in reverence to those Terran memories. Now within the Second Chapter as part of the Primarch's restructuring, they operate as hulking fire platforms and support vehicles, a rolling bastion capable to killing and healing in near-equal measure.

Design
A monolith of a vehicle, the Oróion Citadel could even be classed as a small titan from it's size alone, coming up to the chest height of a Mars pattern Warhound, and twice it's length. With that much mass it is armoured and armed itself significantly, with thick armour plating on all sides it has been able to shrug off significant damage, despite lacking a void shield normally used for a vehicle of it's size. It's unique chassis is much different from normal superheavy tanks found within Imperial armouries, with the front half of the vehicle essentially one large sloped surface. The rear is a large block that is mostly hollow, with a set of large armoured doors that allow vehicles to enter and exit the repair bay.

Rather than the usual method of having tracks mounted within the chassis, the Oróion has 4 sets of large tracks on individual pods attached on either side of the chassis. Mounted on gyroscopic joints they can move independently giving the large vehicle an extra degree of mobility over rough terrain. Armoured as well as a superheavy tank themselves, each of the tracks are separate allowing for both easy replacement when damaged and redundancy should one or more of them be destroyed during combat. On occasion it has been shown that the superheavy can even operate on 2 sets of tracks alone.

While a slow moving vehicle the redundancy and heavily armoured nature has allowed them to survive some of the worst horrors the 1st Legion has faced. The reliability of such a monstrous platform has meant that from Terra to the farthest reaches of the crusade, the vehicle remains has changed little over the centuries of warfare it has experienced.

Armaments
While originally on Terra, the Hy Brasil Dracos had outfitted the Oróion with several formidable weapon systems, but even this was not enough for the 1st Legion as the threats the galaxy posed required nothing short of devastation. Many systems have been retrofitted or replaced while other have been kept in peak condition, but the superheavy tank has lost none of it's potency under the Revenants guiding hand.

Main Weapons

 * 2x Barbarosan Cannon

Seondary Weapons

 * Twin-Linked Autocannons
 * 4x Omega Plasma Array
 * 2x Arcus Launcher

Tertiary Weapons

 * 8x Kheres Pattern Assault Cannon

Over the years within their armoury, the Iron Revenants changed the machine drastically from it's Terran counterpart, most notably would be it's Barbosan Cannon. Though initially mounted with a single devastating cannon the the loss of multiple Citadel class tanks left them with a surplus of the main weapon. The ingenuity of the Legion tech-wrights would lead to them adapting the single weapon turret into a dual setup, mounting a pair of Barbosan Cannons on either side of the main support and sighting array. Monstrously powerful things, the Barbosan Cannons are slug-launching weapons that rival some titan weapons in firepower. Esoteric motors and launcher slings accelerate the heavy slug to extreme speeds capable of sending shock-waves through any target that is hit. The sheer damage caused by the marine-sized slugs can crack layers of ferrocrete and adamantium with ease. Powerful enough to send shockwaves through the targets, causing miniature earthquake tremors or armour and foundations to shake and twist themselves into wreckage as a result.

While the original design was able to fire while moving, the Revenant refit has reduced the vehicle's tactical mobility as the twin cannons being fired requires the vehicle to be stationary.

Mounted themselves on a single rotating turret, the cannons have a slightly limited field of fire thanks to the sloping frontal armour. It is thanks to this peculiarity of design however, that the cannons can be aimed significantly higher that normal tanks, a peculiarity that commanders have been happy to exploit. Thanks to this the cannons can be used in a limited capacity as frontline artillery, supporting artillery barrages and assaults against fortifications with ease. There has been many a time that the guns of an enemy fortress have bounced pitifully off of the Citadel's armour while it's cannons have broken walls allowing troops and tanks to pour through the gap.

Internal to the tank itself are a pair of large ammunition feeds and loader clamps to move the ammunition into place, while the spare rounds are housed within their own armoured compartment to prevent cook-off should the Oróion's armour somehow be penetrated.

A secondary pair of twin-linked autocannons have also been mounted onto the turret to act as a coaxial weapon between the Barbosan Cannons firing also acting as backup guidance for the main weapons through the use of tracer rounds.

Living up to it's name 'Citadel' the tank wouldn't be complete without a set of weapons for air defence and it comes well equipped for the job. Though drawn from a particularly controversial project, a pair of Arcus Launchers have been added to it's arsenal. Mounted on top of the massive tank on individual plinths, they are given a full arc of fire around them and fire near-vertically to destroy any airborne target. Carrying a number of specialised missiles both heavy dropships and swarms of light craft can be killed with equal lethality, reloading from internal magazines that chain ammunition up to the turrets. Machine-spirits leave the turrets within the missiles themselves while extremely potent, are a point of contention between the 1st and the forces of the Mechanicum, meaning that any time a Oróion is fielded alongside the Martian sect it will usually draw the ire from those Magos present.

As part of the post-reunification refits several new weapons were fitted around the vehicle's, superstructure, compensating for some of the flaws pointed out by Araphel upon inspection of the Oróion Citadels. To fill this exposed niche each of the armoured tracks had a singular turret mounted on top of them for extra firepower. To save on space within the pods limited size energy weapons were chosen, being fed from the main reactors by cables instead of having to give up more armour for ammunition storage. As per their Primarch's request each turret was fitted with an Omega Plasma Array to give it incredible anti-vehicle capabilities, though each drew a significant amount of power for normal vehicles, the sheer size of the Oróion's plasma generators were more than enough to keep their appetite's fed. Able to rain down hails of plasma onto enemy vehicles or even produce a continuous plasma beam these secondary turrets allowed the Citadel to rely less on allied tanks for anti-vehicle support as it's main gun and chassis proved far too unwieldy to take on hordes of smaller tanks.

As a final element held over from it's time with the Hy Brasil Dracos, numerous sponson mounts and turrets are places all over the vehicle, meant to cut down hordes infantry like wheat before a scythe. Initially mounted with a variety of scavenged and hoarded archeotech devices found on Terra, the tech-wrights of the First saw fit to replace these relics with more manageable weapons due to their complexity. Instead each has been fitted with a Kheres pattern assault cannon with their own individual ammunition feeds to keep them supplied. Placed strategically around the vehicle -with one on the side of each track pod, one mounted under the main Barbosan cannons and one mounted into the roof of the repair bay- they provide all-around defensive capabilities.

Control Systems
Such a behemoth would usually require a small forces of warfare officers and adjutants to effectively control, let alone coordinate a battlefield from, but the Citadel is no normal Imperial Army command vehicle. Crewed by a mixture of 1st Legionnaires, Legion serfs and tech-wrights from Sol their combined expertise allows for reams of battle-data to be parsed and fortifications felled all in the same command-cycle.

Nestled behind layers of armour and gun barrels is a small but complex suite of command thrones and data-screeds, it is here in the command room that the battle is orchestrated from a battlefield to even planetary level. A single Iron Revenant commander sits in the throne overseeing all of the outstations, with several techmarines seconded in sub-thrones. On the outer layer are several more thrones manned by legionary serfs feeding information and parsing battle-data into relevant sub-strings for their commanders. From these positions the many ebbs and flows of a battleplan can be brought together as the Oróion marches forward on enemy fortifications.

With the entire rear section dedicated to the repair bay it is no surprise then they it has it's own suite of protocols and controls to facilitate it's function. In a small control room located at the rear of the bay it holds a commanding view above the deck and walkways overlooking them. This is a mixed control room however as the rear half has a bank of consoles that are used for controlling the assault cannon stations pockmarked around the Oróion's chassis. Alongside this the central holotable can be converted as a backup command station should the primary one become compromised or destroyed.

In terms of normal operation the senior tech-wrights and support staff all work and are commanded from this overlook, including the gantries above. From here vehicular damage can be categorized, and prioritized for the repair crews below, replacing sponson mounts or even whole slabs of adamantium armour.

Defensive Systems

As would be the Imperial standard for many millennia to come, titan-class war machines and others of a similar size would usually mount one or even multiple void shields, it is a curiosity to most then when they find out that the Oróion Citadel doesn't mount any at all. While an oddity among those of it's weight class it has a particularly good reason for this perceived lack of defence, namely it's armour. A confusing and complex thing even the tech-wrights of Terra seem to have trouble pinpointing the exact nature of how the armour works, simply admitting that even some of the wonders from the Golden Age of Technology escape their minds too. It should also be noted that the idea of mounting void shields has been considered it would require such a large investment in space that it would severely cut down on both the repair capacity of the rear bay and the range of the vehicle thanks to the extra power needed that it was determined to be unnecessary.

What is know is that it is the layout that helps it withstand the enormous firepower that not of only the legions on Terra, but the myriad of xenos weaponry as well. There are 2 distinct layers of metals that protect the vehicle, armour directly attached to the chassis and a secondary layer placed over the top of that. This would simply be a case of super-hardened materials that had since been lost within the last few millennia, but the real trick is what's between these two layers. In thousands of small pockets indented on the first layer of armour an unknown gelatinous substance with a membranous outer layer covering them up. With the secondary layer of armour mounted over the top they act as an elastic buffer when the outer layer is hit, transferring kinetic and energy-based blasts into the pockets as heat with an alarming efficiency. After a certain amount of energy is stored within this liquid it then 'bleeds' the energy out as vapour, seemingly 'sweating' it away into the atmosphere and cooling the substance once.

This bizarre method of reducing incoming damage has been noted by Legion and Imperial authorities. Having to fight the beasts during the Unification Wars several methods of bringing the beasts down were devised with subsequent countermeasures being installed during their major refit thanks to Araphel. As of yet neither Tech-Wrights nor Mechanicus have been able to make any strides in learning about the nature of the metal or the gel, but are still being currently studied thanks to leftover parts from lost machines during the early Crusade.

Although entirely optional there is a final element that can be added to protect the vehicle even more, namely infantry emplacements. Thanks to the large flat top of the Oróion -only obstructed by the twin Arcus Launcher pylons- it can have several pre-fab ceramite bunkers and barricades mounted to allow a small infantry force to garrison it. Working as a deterrent to any would-be boarders or to add their on firepower to the Citadel's own arsenal, focusing on smaller groups of enemies. The force itself is usually a mixture of Astartes and legion serf militia with various heavy weapons emplacements and ammunition storage. The bunkers and barricades have also been augmented with leftover metal from previously wrecked Oróion's to ensure that they can withstand the onslaught and keep their charges intact.

Miscellaneous
Central to the secondary mission of the Oróion Citadel is the repair bay, filled with all manner of processing and manufacturing wonders that allow the dedicated crews to strip away slagged armour and wiring and get it back into the fight in record time.

Thanks to the extensive space within the rear of the vehicle the repair bay has a number of technological wonders that help support their efforts. Small molecular stations can modify and create specialised parts that might otherwise take weeks to acquire, storage bays along the side are filled with all manner of armour plating that can be used to replace destroyed vehicle shells. With the help of overhead gantries and large servoarms vehicles and materials can be positioned appropriately and expedite the repair process even further.

Tech-wrights and support staff work quickly to diagnose the specific damage done as vehicles are brought in, prioritizing the damage done while cross-referencing what stores they have at their disposal. Even if a predator can't be fully repaired it will be brought back to working order enough that it can get back onto the battlefield to win the day.

It has also been observed that a limited amount of self-repairs can be accomplished by the support staff teams, occasionally venturing from their safe haven within the repair bay to work on damaged elements of the Citadel. While this is obviously dangerous work it is considered vital that the mobile fortress remain in peak condition, a sentiment learned from the many other Oróion's lost since the Iron Revenants left Terra.