The ATIS Imperial Planetary Forces former primary Main Battle Tank for direct armoured surface warfare. The Heavy Planetary Assault Vehicle, designation, Generation 2, 205MM gun, Gravimetric, is a progression of the HPAV-1205 tracked armoured vehicle used by the former UAS Ground Forces during the New Federal Era. The HPAV-2205G represented a significant upgrade for Imperial Service, including a new Gravimetric propulsion system, improved armour composition incorporating the latest Nano-polymer Composite technologies as used on the latest Imperial warships in service. Unlike the HPAV-1205, the 2205 is equipped as standard, with an additional side-mounted Non Explosive Reactive Armour (NERA) package with additional Self-Healing ablative layers for additional protection from side attack anti-tank weapons.
The gravimetric propulsion allows for excellent mobility in all terrain conditions, but some reductions the vehicle's weight were necessary to reduce overall mass to allow a viable power requirement for the Gravimetric gryo (non linear increase in power requirements as mass increases to sustain the gravimetric repulsion field). As a result, the vehicle's base armour is somewhat thinner than the Generation 1 tracked vehicle, but improved composition largely nullifies this disadvantage, along with the inclusion of an advanced Active Protection System (APS) and Active Countermeasure and Camouflage suite (ACC) giving the HPAV-2205G Excellent survivability against most threats, despite the reduced weight.
The main armament remains the G/F-205 Magnetically Assisted Fission Impulse Mass Driver as used on the Generation 1 vehicle, but it does incorporate an enhanced Fire Control System Director (S-AI) for superior on-the-fly ballistics calculations, improving accuracy at extreme ranges.
The HPAV-2205G was the backbone of the ATIS Planetary Forces' armoured capability, and almost all mechanised and armoured surface divisions were equipped with at least one full company of the MBT as standard. It was replaced in 4425 A.D due to the need for a ground-up design, which resulted in the more capable T-4406 Ogre MBT.
Despite being retired from the IPF's inventory as the standard surface-combat MBT, the HPAV-2205G remains in service with some reserve units and was widely exported to Civic Security departments in down-gunned variants intended for patrol use. The HPAV-2205G is also exported to the Helian Planetary Defence Forces in the HPAV-2205G/E variant, with reduced reliance on state of the art nanopolymers, but has yet to fully replace the HPDF's incumbent T-502 Walrus MBT due to increased costs of operation.