Self-Propelled Heavy Artillery/Legends

The Self-Propelled Heavy Artillery (SPHA) walker, also known as the Mobile Assault Cannon (MAC),Star Wars: The Clone Wars video game was a modular heavy artillery unit used by the Grand Army of the Republic during the Clone Wars, and by the Galactic Empire afterward. It bore a resemblance to the smaller RX-200 Falchion also utilized by the Republic during the Clone Wars. Depending on the configuration, the walker had different names: SPHA-T (turbolaser), SPHA-I (ion cannon), SPHA-V (anti-vehicle laser), SPHA-C (concussion missile launcher), SPHA-M (mass-driver cannon) and SPHA-F (thermobaric cannon).
==Description==
A Self-Propelled Artillery Walker (SPHA) had twelve legs that served as mobile support structures. Unlike smaller walkers, such as the AT-TE, SPHA units were unable to be carried into battle by LAAT/c gunships because of their large size and weight. Instead, they were deployed directly from landed Acclamator-class assault ships, which could carry 36 of the artillery platforms.
In battle, SPHA walkers usually received orders from ground-based command posts, which provided a less isolated and more in-touch view of the battlefield than the towering walkers. In addition, SPHA units had a complement of 30 clone troopers, which could be deployed rapidly via a dorsal hatch. In seconds, the soldiers could disembark the vehicle and secure the area immediately around the walker, providing protection from enemy infantry and other light units.
===Main weapons===
The SPHA walker chassis served as the basis for a number of different weapons platforms, though the best-chronicled version was the turbolaser (SPHA-T) configuration. This variant's main weapon was a heavy turbolaser cannon, capable of causing extreme direct fire damage to large or slow-moving targets. The turbolaser boasted tremendous range and was capable of penetrating deflector shields.
The primary disadvantage of this powerful weapon was that it was incapable of providing indirect fire support to out of sight locations, a problem remedied in other models. Another disadvantage was that the weapon could only be charged to a certain level—upon firing such shots, they had to be replaced with charged guns from the rear lines.Inside the Worlds of Star Wars: Attack of the Clones
Some of these other variants deployed during the Clone Wars include the ion cannon (SPHA-I), anti-vehicle laser (SPHA-V), concussion missile (SPHA-C), thermobaric burst (SPHA-F), and mass-driver (SPHA-M). Some of these model variations included 12 retractable antipersonnel blasters, necessitating an additional 10 gunners to the command crew of 15.
==History==
===Development===
The SPHA walker was developed by Rothana Heavy Engineering.
The power usage of the turbolaser cannon in the SPHA-T variant dictated the design of the other parts of the vehicle.
Designers rejected a complex turret mechanism, choosing instead to rely on the entire walker repositioning itself in order to adjust for different firing coordinates. Like other walkers, the use of articulated legs prevented the SPHA from being vulnerable to anti-repulsorlift weapons, at the cost of some mobility.
The Galactic Empire later developed a more compact version, the SPMA, which was more mobile and compact, thanks to weight-reducing advancements in technology.
===Usage===
The SPHA, particularly the SPHA-T, first appeared in the First Battle of Geonosis where it was instrumental in bringing down several Lucrehulk-class core ships and Hardcell-class interstellar transports.
SPHA units were used throughout the Clone Wars, seeing action in surface battles such as the Battle of Cato Neimoidia,Labyrinth of Evil the Battle of Muunilinst—where many were destroyed by the nimble IG lancer combat droids—, the Battle of Rhen Var, and the Second Battle of Tatooine.Star Wars: Galactic Battlegrounds: Clone Campaigns
At the suggestion of Anakin Skywalker, many Venator-class Star Destroyers of the Open Circle Fleet had SPHA-T turbolaser cannons installed inside their ventral hangar bays,Star Wars: Revenge of the Sith Incredible Cross-Sections where they were used effectively during the Battle of Coruscant, especially against enemy Munificent-class star frigates.
The SPHA-line walkers continued in service in the early years of the Galactic Empire, until the SPMA-line was developed, with the SPMA vehicles being faster and more maneuverable than the cumbersome SPHA-Ts.
==Behind the scenes==
Concept art of the SPHA-T was drawn by Concept Design Supervisor Erik Tiemens. He initially imagined a treaded vehicle, but George Lucas changed it to a walker. The SPHA's production name was "Clone Tank A".
In both Star Wars: Attack of the Clones: The Visual Dictionary and Star Wars: The Complete Visual Dictionary, the SPHA-T's turbolaser is incorrectly labeled as a troop hatch. Also, in The New Essential Guide to Vehicles and Vessels, the SPHA-T is incorrectly said to be driven by multiple treads. It is in fact a walker, driven by twelve legs.
The size of the vehicle is somewhat indiscernible, as the 140-meter length apparently from The Official Star Wars Fact File 71 does not match the size seen in Star Wars: Episode II Attack of the Clones, or the dimensions used in The New Essential Guide to Vehicles and Vessels physically.
==Appearances==
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*Star Wars: Republic Commando
*Star Wars: Galactic Battlegrounds: Clone Campaigns
*Star Wars: The Clone Wars video game
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*Star Wars: Clone Wars Cine-Manga
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*Jedi: Yoda
*Jedi Trial
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*Labyrinth of Evil
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*Star Wars: The Force Unleashed 
==Sources==
==Notes and references==
Category:Mobile artillery types
Category:Rothana Heavy Engineering products
Category:Vehicle classes of the Galactic Empire
Category:Vehicle classes of the Galactic Republic
Category:Walker models