Self-Propelled Heavy Artillery Turbolaser

Combining the devastating firepower of a permanent laser cannon emplacement with the ability to liberally walk into battle on powerful articulated legs, the Self-Propelled Heavy Artillery Turbolaser (SPHA-T), also known as the Self-Propelled Heavy Artillery (SPHA), were the largest ground based weapons in the arsenal of the Grand Army of the Republic at 140.2 meters in length. It only used its twelve legs when maneuvering between firing positions; when attacking an enemy target, a SPHA-T remained motionless to give its gunners added precision for aiming its extraordinarily heavy turbolaser beam. Although it took no less than 30 specialized clone troopers to man each gun platform, they were powerful and effective enough to blast through starship shields and hulls. However, SPHA-Ts could only be charged up to a certain level.

SPHA-Ts were able to provide defense for assault ships that were landing and devastating direct firepower. The artillery walkers were generally deployed in squadrons of four and were usually placed behind advancing walkers like the All Terrain Tactical Enforcer. Aboard Acclamator-class transgalactic military assault ships, SPHA-Ts were stored behind All Terrain Tactical Enforcer walkers, which were at the front of bays. During the Clone Wars, thanks to Jedi General Anakin Skywalker, some Venator-class Star Destroyer had additional Self-Propelled Heavy Artillery cannons located at their ventral docking bay. These laser cannons increased ventral firepower.

Manufactured by Rothana Heavy Engineering, 100 SPHA-Ts were deployed in key positions on several battlefronts during the First Battle of Geonosis, the opening battle of the Clone Wars. They were deployed in squads of four at the rear of advancing All Terrain Tactical Enforcers, while Low Altitude Assault Transport carriers ensured they were well defended by AT-TEs and infantry on foot, who were mobilized around and in front of SPHA-Ts to a distance of several kilometers. The SPHA-Ts carried coordinating actions with infantry and the AT-TEs to provide an impregnable line of defense for the fleet of Acclamator-class transgalactic military assault ships that landed immediately outside the Petranaki Arena, which supplied an assembly point for the deadly juggernauts. During the battle, they proved particularly effective on the battlefield commanded by Jedi Master Yoda, and one squadron was ordered by Master Yoda to focus fire upon a fleeing core ship. This caused antigrav repulsorlift malfunctions that grated a tractor beam effect with the ground, greatly accelerating its fall and destroying the ship. However, after these shots, the SPHA-Ts had to be replaced with charged guns from the rear lines.

During the Battle of Coruscant, a SPHA-T located in the hangar of a Venator-class Star Destroyer fired upon a Munificent-class star frigate and took the enemy ship out as Skywalker and Obi-Wan Kenobi passed it. After the Clone Wars and the rise of the Galactic Empire, the Imperial Army's Imperial Artillery Corps used the SPHA-Ts as mobile artillery. The SPHA-Ts were eventually replaced by the smaller and faster SPMAs.

Originally created for the 2002 film Star Wars: Episode II Attack of the Clones, the Self-Propelled Heavy Artillery was designed in concept sketches by Concept Design Supervisor Erik Tiemens. His initial concepts had the self-propelled cannon be mounted on treads, but George Lucas instead suggested that it be a walker like its AT-TE cousin. During production, the SPHA-T was called "Clone Tank A." An early animatic featured SPHA-Ts being deployed from Acclamator-class assault ships on Geonosis, though this scene was cut from the final film.

The RX-200 Falchion-class assault tank featured in "The Zillo Beast" and "The Zillo Beast Strikes Back" was redesigned from the SPHA-T to better resemble the maser tanks from the Godzilla franchise.

The 140.2 meter databank size does not visually correlate with the physical appearances in Attack of the Clones of which the Legends size of "Less then 60 meters" comes from. The CGI model used in the film is slightly visually larger than two times the length of an AT-TE, rather than significantly larger as implied by the databank. The 2018 canon reference book, Star Wars Encyclopedia of Starfighters and Other Vehicles authored by Landry Q. Walker, also establishes a length of 140.2 meters.