M27 Centurion II

The M27 Centurion II, commonly known as "Terran Universal Combat Tank" is one of the mainstay Federation Army's armored fighting vehicles that predated the First Bug Wars.

An antiquated Federation Main Battle Tank, the type was no longer in service in the mainstay Federal Army during the Second Bug War, although they are still manufactured for colonial garrisons which lack access to high-end equipment and maintenance facilities.

Description
The Centurion design was based on the principle of hit-and-run defensive tactics back during the Disorder Wars period on Earth. Designed to be mobile and small, with greater flexibility compared to its successors, its small chassis means it can move up relatively narrow mountain roads, and more can be fit upon trains and transportation. With the Federation rethinking their mindset on the more defensive doctrines for their armored units, these defense minded vehicles outstayed their welcome. This proved to be a liability for these vintage tanks, when the Federation launched their retaliation campaigns against the Arachnids and the Batarians. But despite its age they maintained excellent defensive capabilities, as everything from Skinnie Chariots to Batarian Varush tanks learned to fear its assault gun variant, the Dustbin.

Already when the 2nd Bug War came to an end, these vehicles showed their age, and it was only made worse with the discovery of the Mass Effect technology. Originally just an old variant for a style of warfare made impossible by the Bugs and Skinnies, it was quickly rendered obsolete by advancing technology from the Citadel League. The most obvious disadvantages was the lack of a kinetic shield, along with inferior metallurgical protection against hi-velocity Mass Accelerators, these quickly proved to be fatal for the unfortunate crew of these tanks which faced raids from the Terminus and Batarians. Nevertheless, they are still being mass produced and constantly upgraded with up-to-date equipment. Examples of these upgrades include ablative laser proof coatings, improved thermal sensors, state of the art armor plating, and improved engines.

The tank has a reputation for being cheap, fast, and reliable. Able to run on anything that burns, can reach up to 88km/h in favorable off road terrain, being relatively easy to maintain, and can mount a variety of weapon systems. It maintains the Federation’s desire for modularity, with the various turrets able to be replaced, and casement weapon’s also able to be swapped out. Typically used for garrisons in defensive actions, the tank has a reputation for being the Colonist’s vehicle of choice, with it pulling double duty in farming, mining, forestry, and many more industries, with the Colony of Neo Novogorsk claiming it as their Planet Vehicle.

Variants
M27 early models (Mark I to Mark IV):

Standard Main Battle Tank, armed with a Thunderstrike cannon and a co-axial 12.7mm HMG. Nicknamed “Centurion”, most has been retired from Federation service after 2nd Bug War.

M27CS Dustbin Assault Tank: Close support vehicle, armed with a 240mm Hail-Mary Mortar mounted in a modified turret, designed for demolition, close support, anti fortifications, and harassment fire. Also has a pintle mounted 12.7mm HMG. Nicknamed “Dustbin”.

M27IP Improved Performance Main Battle Tank:

The M27IP (Improved Performance) Centurion II is an upgraded variant of the original M27 Centurion II main battle tank. Originally designed as a stopgap to the production delays and technical problems with the newer M40 Susanoo models, the new tank was fitted with the turrets intended for the early version of the Susanoo in an attempt to rectify the Centurion II deficiencies in firepower against more powerful armored walkers deployed by the Pseudo-Arachnids, the Afrodisians and the Forths. This variant was nicknamed “Thunderbolt” due to the sound of the high velocity ionized plasma projectile fired from its barrel as well as the blinding flash produced by the plasma railgun after it fired its charged shot.

Unlike conventional Mass Accelerator patterns, the Terran's made Rosenkov RD-10 125mm Plasma Railgun was designed to fire an armature and a projectile consisted of hot ionized concentrated bolt of plasma instead of a solid slug at a velocity of 2,200m/s. Utilizing the 125mm plasma railgun turrets originally intended for the Susanoo MBTs as a stopgap due to delays in Susanoo production, this vehicle excels in anti-tank warfare, delivering powerful plasma shots with its hi-velocity cannon.

Despite the fact the gun can attains relatively long firing range at 6km, the air resistance and various in-atmospheric gases tend to interfere with the performance of the plasma shot, rendering it ineffective as the longer the projectile travels the slower and less effective it become.

Further problems included the bright flash from the gun's armature due to the amount of heat build-up during the charging duration as well as the more cramped design of the smaller Susanoo turrets. As a result, the Centurion Thunderbolt had a slower rate of fire and slower traverse than the average 140mm armed Centurion. This combined with less effective scattering shot for anti-infantry and anti-fortifications mean many Terran tank crews still refused to switch to newer model due to the superior performance of the 140mm rifled tank guns against soft targets.

In spite of these problems however, the railgun is still very effective as an anti-armor weapons, once the difficulties of fitting the railgun turret and corecting the design problems with the RD-10 Plasma Railgun mounting were done with, the Centurion Thunderbolt became the most common railgun-armed Terran combat vehicles of the Batarian Wars, typically seen operating as fire support units for the Marauder units of the Mobile Infantry in the heat of battles.

M27 Centurion II Mark X/M28 Ariete III:

Initially developed as enhanced export variant of the baseline M27 Centurion II for other Terran allies and their autonomous colonies as well as various various paramilitary organizations. The M28 Ariete (Ram) III was also adopted by the Terran Federation Armed Forces as M27 Centurion Mark X "Sakeen" (Hebrew for "knife"), although the type had been largely superseded in frontline service in the mainstay Terran Federation military by newer designs and 2nd gen Marauders, these tanks still continue to see service in other Terran colonies and a number of other factions and private military corporations.

In an attempt to extend the service life of the old Centurion II tanks by a few more decades, the new version had a redesigned welded turret with improved active protection system with a field upgrade kit with add-on ERA protective plates which was bolted around the turret with thermal coatings for countermeasures against lasers and plasma weapons. In addition, it also received a new turret derived from the M40G Susanoo Kai MBTs with new high muzzle velocity 152mm smoothbore cannon and capable of firing ATGMs. This solution was cheap and easy to implement, though its effectiveness was marginal at best. Compared to the baseline Centurion II, the armour protection was greatly improved, but still prove to be insufficient against more modern mass accelerator and plasma weapons.

M67 Rocket Tank:

Armed with a Spitball Rocket Launcher, this vehicle performed the role of long range artillery, providing rocket fire support for front line units. Nicknamed “Hydra”

M77 Self Propelled Anti-Aircraft Artillery:

Modified SPG variant with modified variant of the M779 Ultra-light weight automatic howitzers, also designed for direct fire support for frontline units. Nicknamed “Bishop”.

CVTS-12 Armored Recovery Vehicle:

An armored recovery vehicle based on the chassis of older Centurion II models, the acronym CVTS stands for Combat Vehicle Technical Support, indicating the role of the vehicles. As of 2668 CE, the Federation had over 30,000 vehicles in service, standard equipment set includes: automated crane with telescopic jib that can lift maximum weight of 20 tons, front-mounted stabilizing dozer blade similar to the Centurion II Dustbin Assault Tank model, main and secondary winches, as well as provision for atleast 10 pairs of smoke/flare/chaff dischargers. Main armaments included a turret cupola for the commander with a pair of Morita 12.7mm Heavy Machine Guns. Nicknamed "Bison".

SA183 Self Propelled Howizer:

The SA183 Olifant is a self propelled howitzer based on the chassis of the M27 Centurion II Main Battle Tankbut with six roadwheels instead of five per side. It used a lightly armoured, fully enclosed and traversable turret housing a Tula Naval Arsenals M10C 183mm Heavy Howitzer and capable of 45 deg elevation and -10 deg depression.

The Olifant, being converted from older M27 chassis, shared a number of components with the M27 Centurion II parts. In additions to its role as a self-propelled artillery platform, the SA183 is also often used as direct fire Assault Gun in lieu of Main Battle Tanks for supporting infantry in combat.

In order to accomplish this role, the turret was enlarged to fit an autoloader which allows it to reload just as fast as an average MBT, the 183mm gun can also fire both effective HEAT-FS and conventional HE Fragmentation shells, however due to worse turret armor protection compared to its MBT counterparts and the lack of coaxial weapons, the Olifant can be easily disabled by chemical explosive projectiles and were highly vulnerable to hand-held anti-tank weapons, for that reason, the SA183 is always seen operating with infantry support or alongside other MBTs to provide it a a measure of protection against hostile infantry and tank units

Accepted in service after the failure of Operation Bug House to replenish the losses of armored vehicle assets on Klendathu, more than 23,000 chassis had been manufactured and still in service with the Federation to this day. Nicknamed "Olifant".