MBT-27 Centurion

51 tonnes (B variant, standard loadout)

B variant

* (1) Autoloaded 134mm Kinetic Accelerator Cannon
* (1) 20mm Coaxial Autocannon
* (1) Optionally top mounted RWS for the commander

Limiter off: 100 km/h

The MBT-27 Centurion is a next generation main battle tank developed by the United Earth Federation to serve as its primary front line tank. It saw a long service life with a fair amount of variants both upgrades, derivatives and experimental types. The tank saw heavy use and action during the 1st Interstellar and also the Sentinel Wars, before being replaced by the MBT-29 in active service by the 25th century.

Due to its long service in the UEF, it has earned itself the nickname 'Century Tank'.

## Development History

The MBT-27 was designed to be cost efficient while retaining a balance of speed, firepower and armor. It was a joint development project for the first time after the formation of the UEF, being jointly developed by the Russian Federation, United States, Germany and Japan with further contributions from the United Kingdom, France, China and the Southern African Republic.

### Origin

The need for a global, universal main battle tank was first conceived in 2079, one year after the formation of the Federation Army to protect the newly formed Federation's interests and in the scenario of a 'Space War'. This came after the issue of having multiple tanks from multiple countries was brought up, such issues included; logistics, coordination, transportation and research and development. As such, in 2081, multiple tank programs from multiple countries were merged.

The MBT-27 was the final result of these mergers and it was decided to use the United States' XM3 Program or Project Crusader as the basis. The task of development was originally primarily handled and split between countries with experience of tank development, these countries included; the United States, Russian Federation, Germany and Japan. In 2085 however, the program was further expanded to the United Kingdom, France, China and the Southern African Republic. By 2087 the program was global with many other countries contributing in production and technology sharing.

### Upgrade

In 2206, the MBT-27 received a upgrade designated the B model or MBT-27B. It was armed with a newly developed 134mm Kinetic Accelerator Cannon (simply shortened as KAC) which increased penetration, velocity and lethality all together. This upgrade was a subsequent result of the federation BW-Alpha Plan in preperation for the war with the Icarusian Empire.

### MBT-29 Gladiator

The MBT-29 Gladiator was a further development of the MBT-27 Centurion utilising new technologies such as newly developed plasma weaponry.

## Design

### Armament

#### Primary

The MBT-27 was initially equipped with a advanced, high-velocity 130mm smoothbore gun with ETC technology that fired telescoped ammunition. It was supported by a turret bustle autoloading system which eliminated the need for a loader. The bustle rack carried a total of 40 shells maximum with varying different shells.

The upgrade in 2206, dubbed the B model or MBT-27B, however used a newly developed kinetic accelerator cannon, a cannon that utilised both electricity and a specialised plasma charge to propel the projectile at hyper velocity speeds. Essentially a hybrid between a conventional cannon and a railgun. Like its predecessor, the new 134mm KAC used telescoped ammunition with an turret bustle autoloader.

#### Secondary

The secondary armament initally consisted of twin .50 caliber heavy machine guns, designated M7 HMG or HMG-7, as coaxial. It could be further armed with remote weapon systems fitted with either HMG-7s, AGL-4 Automatic Grenade Launchers, M194 Rotary HMGs or a M12 20mm Autocannon.

The MBT-27B in 2206 replaced the coaxial twin HMG-7s with a variant of the M12 20mm Autocannon, designated M12CL, improving lethality against infantry behind cover and light armored vehicles while reducing ammo consumption at the cost of having less ammo. The M12CL carried 440 rounds of ammunition, and is chambered with API (Armor-piercing Incendiary) rounds. However, it can be swapped out with high-explosive or sabot rounds depending on crew preference and mission parameters.

### Protection

The MBT-27's protection had a major emphasis on being light as it was expected to be easily transportable from ships to planets. A major requirement of it was that it was to be well protected but still light enough to have two be carried by the DS-14's specialised vehicle carrier variant, the DS-15.

The MBT-27's ammo storage is armored and separated from the crew compartment to prevent harm to the crew in case of ammo explosion. It is also equipped with blowout panels, to divert the fire and pressure outside of the tank, and the FRS MK.4A fire suppression system.

#### Armor

As the MBT-27 is based directly off the 21st century XM3 Crusader program of the United States, its armor is roughly similar to it with various enhancements done. As modified from the XM3, Project Crusader, it has sharp angles and slopes designed to try and deflect incoming kinetic projectiles and energy from chemical ones. Its turret front is highly sloped and angled, intended to deflect projectiles primarily upwards or to the side rather than downwards in order to prevent a shot trap. This design is reminiscent and a more extreme version of older tanks like the M1 Abrams and M2 Schwarzkopf of the United States, the Challenger tank series of the United Kingdom and the *Löwe* 1 (or Lion 1) of Germany.

The MBT-27 uses composite armor all around the tank except for the rear plating of the engine. The composite armor is a mix of titanium and steel alloys, supported by carbon nanotubes and sandwiched with ceramics made of an enhanced variant of boron carbide on both ends. Internal plates are further made up of primarily kevlar and ceramics for crew comfort and additional protection from heat or fragmentation. The rear part, the engine compartment and the engine deck, is only covered by the steel base of the hull supported by ceramics. The top armor of the tank is designed to resist fragmentation and low-level anti-tank weapons, however it is still the weakest part of the tank along with the rear section.

#### Countermeasures

Smoke grenade launchers are mounted on the turret with airburst capability. Two with 8 barrels were mounted in front with a further two with 4 barrels facing the rear. During the B model upgrade and design process, the MBT-27 also borrowed the SPS-44 Warden soft-kill APS from the RTD-575 Matador.

In the 1st Sentinel War, a new type of smoke grenade was introduced which mixed small special metal materials into the grenade that when released, create small, confetti-like reflective materials along with the smoke which increased its ability to block thermal vision as well as an added ability to scatter much of the concentrated energy of plasma bolts and beams, effectively creating a temporary shield. This proved useful against Sentinel weaponry which consisted primarily of plasma weapons. However, infantry standing near the deployed smoke would be in harms way as the plasma is scattered in all directions in a short range, creating a fragmentation effect. As a result, this type of grenade was never adopted into infantry use. Many MBT-27Bs were refitted with this mid-war, and by the late war, all active armor units were equipped with it and was notably fitted on the D model and MBT-28s.

Some vehicles were also mounted with a hard-kill active protection system on top of the turret in the form of a small, 360 rotating launcher that fired small intercepting projectiles. This system was known as the APS-56 'Custodian' and had 18 shots. Unofficially any vehicles equipped with the system were known as the MBT-27G or 'Guardian'.

***WORK IN PROGRESS***

## Variants

* **MBT-27A -** Initial production variant, used up until 2206 before being replaced by the B model. All produced MBT-27A up to that point were later upgraded to the B model standard.

* **MBT-27B -** An upgraded model of the previous design initiated in 2206 in response to the Icarusian Empire threat. Upgrades included the new 134mm KAC replacing the old conventional 130mm smoothbore cannon, replacing of the twin .50 coaxial with a single 20mm coaxial autocannon, improved drivetrain, a new FCS and also introduced a soft-kill active protection system.
* **MBT-27C -** An experimental upgrade that fitted a M75 Type 2 150mm KAC from the MTU-575 Matador. Only reached prototype stage with 20 MBT-27B's being converted. All were assigned to the 841st Armored Battalion of the 52nd Armored Division and participated in the Battle of Planet Yakul. Saw somewhat successful use, however the autoloading system proved hard to maintain on the MBT-27 compared to the MTU-575 and it was decided not worth the cost to continue development of this type.
* **MBT-27D / MBT-27D1 -** A late upgrade model near the end of the 2nd Sentinel War. It removed the 4th crew member position for extra free space within the turret-hull, replaced the 134mm KAC with a powerful 120mm Railgun as well as improved armor layout for increased protection and survivability. Many, if not all, MBT-27Bs were upgraded to this new model or the later MBT-27D2/MBT-28A model.
	+ **MBT-27D2 / MBT-28A -** Another late upgrade model that saw service in the 3rd Sentinel War, complementing the MBT-29 before it reached mass production. Turret was overhauled with a similar turret from the MBT-29 program, using the same MK-P1 1st Generation Plasma Cannon used on the MBT-29 and a upgraded engine to power the new cannon. Initially designated MBT-27D2, was redesignated MBT-28A when it entered service. This variant and the original MBT-27D made up all of the Federation's MBT-27s produced by the end of the Sentinel Wars.
* **MBT-27CM -** Command variant. Slightly larger turret and removed a portion of the ammo storage compartment for extra communication and command equipment as well as the addition of a long range command radio. In order to avoid confusion with other upgrade variants, specifically MBT-27C, all variants modified to this variant simply had CM added onto their already existing designation. No command variant of the C model exists.
	+ **MBT-27A-CM**
	+ **MBT-27B-CM**
	+ **MBT-27D-CM**
* **MBT-27G 'Guardian' -** Unofficial designation for vehicles equipped with the APS-56 Custodian hard-kill active protection system.
* **MRL-25 Arbiter MLRS -** A specialized variant. It saw the removal of the turret and replaced by a M725 Rocket Launcher Turret (RLT). A new FCS to work with the new rocket launcher and crew was limited to 3 (Driver, gunner, commander). The M725 RLT was capable of being configured with multiple different modules, each with different rockets or missiles.