Self-Propelled Heavy Artillery

Production information

Manufacturer

Rothana Heavy Engineering^[1]^[2]^[3]^[4]

Model

Self-Propelled Heavy Artillery^[1]^[2]^[4]

Type

Walker^[1]^[2]^[3]^[4]
Mobile artillery^[1]

Technical specifications

Length

40.15 meters^[5]

Height/depth

20.6 meters^[6]^[4]

Maximum speed

35 km/h^[2]^[7]^[4]

Shielding

Equipped^[2]

Armament

Main weapon (1)^[3]^[8]
- Turbolaser^[7]^[3]^[8]^[4]
- Ion cannon^[3]^[8]^[4]
- Anti-vehicle laser^[3]^[8]^[4]
- Concussion missile launcher^[3]^[8]^[4]
- Mass-driver cannon^[7]^[4]
Antipersonnel blasters (12) (optional)^[3]^[8]^[4]

Crew

Primary crew (15)^[3]^[2]^[8]^[4]
Gunners (10)^[3]^[2]^[8]^[4]

Minimum crew

12^[9]

Passengers

20^[2]^[8] - 30 clone troopers^[9]

Cargo capacity

500 kilograms^[7]^[2]

Consumables

1 week^[7]

Usage

Role(s)

Self-propelled artillery^[1]

Affiliation

"Using this weapon against droids is a necessary evil. But what if such destructive power should be turned against living creatures? A sad thought, indeed."

―Mace Windu^[6]

The Self-Propelled Heavy Artillery (SPHA) walker, also known as the Mobile Assault Cannon (MAC),^[12] 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

"Their range is greater than we thought."

―A Muun during the Battle of Muunilinst^[13]

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.^[1]

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

An frontal view of a SPHA with a clone trooper for scale.

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.^[3] The turbolaser boasted tremendous range and was capable of penetrating deflector shields.^[6]

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.^[14]

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).^[7] Some of these model variations included 12 retractable antipersonnel blasters, necessitating an additional 10 gunners to the command crew of 15.^[3]

History

Development

An SPHA-T walker battery protected by columns of and . — An SPHA-T walker battery protected by columns of clone troopers and AT-TEs.

The SPHA walker was developed by Rothana Heavy Engineering.^[3]

The power usage of the turbolaser cannon in the SPHA-T variant dictated the design of the other parts of the vehicle.^[3]

Designers rejected a complex turret mechanism, choosing instead to rely on the entire walker repositioning itself in order to adjust for different firing coordinates.^[3] Like other walkers, the use of articulated legs prevented the SPHA from being vulnerable to anti-repulsorlift weapons, at the cost of some mobility.^[3]

The Galactic Empire later developed a more compact version, the SPMA, which was more mobile and compact, thanks to weight-reducing advancements in technology.^[15]

Usage

SPHAs concentrate fire on a fleeing . — SPHAs concentrate fire on a fleeing *Lucrehulk*-class Core Ship.

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.^[16]

SPHA units were used throughout the Clone Wars, seeing action in surface battles such as the Battle of Cato Neimoidia,^[17] the Battle of Muunilinst—where many were destroyed by the nimble IG lancer combat droids—,^[13] the Battle of Rhen Var,^[12] and the Second Battle of Tatooine.^[18]

An SPHA-T fires its at a from inside the hangar of a . — An SPHA-T fires its turbolaser at a *Munificent*-class star frigate from inside the hangar of a *Venator*-class Star Destroyer.

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,^[19] where they were used effectively during the Battle of Coruscant, especially against enemy Munificent-class star frigates.^[20]

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.^[15]

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".^[3]

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.^[3]

The Official Star Wars Fact File 71 claims the SPHA-T is 140.2 meters long but that does not match the size seen in Star Wars: Episode II Attack of the Clones, the dimensions used in The New Essential Guide to Vehicles and Vessels physically or the listed length in Star Wars Chronicles: The Prequels.