The Self-Propelled Heavy Artillery (SPHA), which is also referred to as the Self-Propelled Heavy Artillery Turbolaser (SPHA-T) when it is outfitted with a turbolaser emplacement, represented a versatile, multi-component gun platform. Rothana Heavy Engineering was the manufacturer of this twelve-legged weapon system. During the [Clone Wars](/article/clone_wars], these platforms served as the Grand Army of the Republic's most massive ground-based weapons. Later, during the Imperial Era, the Galactic Empire employed SPHA-Ts within its Imperial Artillery Corps.
The Self-Propelled Heavy Artillery Turbolaser (SPHA-T), alternatively called the Self-Propelled Heavy Artillery (SPHA), combined the destructive power of a built-in laser cannon emplacement with the capability to advance into combat on strong, jointed legs. These units, measuring 140.2 meters in length, were the most sizable ground-based weapons available to the Grand Army of the Republic. The twelve legs were primarily used for repositioning between firing locations; when engaging a target, the SPHA-T would remain stationary to improve the accuracy of its gunners when aiming its extremely powerful turbolaser beam. While each platform required a crew of at least 30 specialized clone troopers, their effectiveness allowed them to penetrate starship shields and hulls. However, the SPHA-Ts had a limit to their charging capacity.
SPHA-Ts were capable of providing both defensive cover for landing assault ships and significant direct firepower. Typically, these artillery walkers were deployed in squadrons of four, positioned behind advancing walkers such as the All Terrain Tactical Enforcer. Onboard Acclamator-class transgalactic military assault ships, SPHA-Ts were stored behind All Terrain Tactical Enforcer walkers at the front of the bays. During the Clone Wars, thanks to the efforts of Jedi General Anakin Skywalker, some Venator-class Star Destroyer vessels were equipped with supplementary Self-Propelled Heavy Artillery cannons situated in their ventral docking bays, enhancing their ventral firepower.
Rothana Heavy Engineering manufactured 100 SPHA-Ts, which were strategically placed across various battlefronts during the First Battle of Geonosis, marking the commencement of the Clone Wars. These units were arranged in squads of four, stationed behind advancing All Terrain Tactical Enforcers. Low Altitude Assault Transport/carriers provided essential defense, ensuring the SPHA-Ts were well-protected by AT-TEs and ground-based infantry. These forces were mobilized around and ahead of the SPHA-Ts, extending several kilometers. The SPHA-Ts coordinated their actions with infantry and AT-TEs to establish an impenetrable defensive line for the fleet of Acclamator-class transgalactic military assault ships that landed just outside the Petranaki Arena, which served as a staging area for these formidable machines.
During the battle, they demonstrated exceptional effectiveness on the battlefield under the command of Jedi Master Yoda. Master Yoda directed one squadron to concentrate fire on a retreating core ship. This action resulted in antigrav repulsorlift malfunctions, creating a tractor beam effect with the ground, which significantly accelerated the ship's descent and led to its destruction. However, following these shots, the SPHA-Ts required replacement with fully charged guns from the rear lines.
During the Battle of Coruscant, a SPHA-T positioned within the hangar of a Venator-class Star Destroyer engaged and destroyed a Munificent-class star frigate as Skywalker and Obi-Wan Kenobi passed by. Following the Clone Wars and the rise of the Galactic Empire, the Imperial Army's Imperial Artillery Corps utilized SPHA-Ts as mobile artillery platforms. Eventually, the SPHA-Ts were superseded by the smaller and faster SPMAs.
The Self-Propelled Heavy Artillery was initially conceived for the 2002 film Star Wars: Episode II Attack of the Clones, with concept sketches developed by Concept Design Supervisor Erik Tiemens. His original designs featured the self-propelled cannon mounted on treads, but George Lucas suggested it should instead be a walker, similar to its AT-TE counterpart. During the production phase, the SPHA-T was referred to as "Clone Tank A." An early animatic showcased SPHA-Ts being deployed from Acclamator-class assault ships on Geonosis, although this scene was ultimately removed from the final film.
The RX-200 Falchion-class assault tank that appeared in "The Zillo Beast" and "The Zillo Beast Strikes Back" was redesigned from the SPHA-T to more closely resemble the maser tanks from the Godzilla franchise.
The databank size of 140.2 meters does not visually align with the physical appearances in Attack of the Clones, which is where the Legends size of "Less then 60 meters" originates. The CGI model employed in the film appears visually slightly larger than twice the length of an AT-TE, rather than significantly larger as indicated by the databank. The 2018 canon reference book, Star Wars Encyclopedia of Starfighters and Other Vehicles by Landry Q. Walker, also confirms a length of 140.2 meters.