Seismic tank

"The ship's sending out seismic tanks. They look modified."

- Kit Fisto

A seismic tank, also referred to as "seismic charge minelayer" or "seismic hover tank," was a repulsorcraft that traveled very close to the surface of a planet and inflicted damage to an opposing force by ejecting a large piston downward onto it, smashing them, and then creating a shockwave that rippled away from its impact zone. It was originally designed by Haor Chall Engineering for the Commerce Guild as a mining vehicle used to tear up the surface of a planet to reveal precious minerals. However, with the outbreak of the Clone Wars between the Galactic Republic and the Confederacy of Independent Systems, the tank was put to military use on battlefields such as Dantooine and Ukio.

Characteristics
"Very strange density readings, but I'm not picking up any weapons or explosives."

- Kit Fisto

The seismic tank, also referred to as "seismic charge minelayer" or "seismic hover tank," was a massive repulsorlift craft with a huge seismic driver in its core. Magnetic impellers guided the driver, which was almost frictionless, through a channel located in the center of the tank. The heavy metal core of the driver gave it an enormous amount of inertia as it fell toward the ground below. The impellers were also responsible for keeping the driver perfectly centered in the channel and for making sure the resulting shockwave did not travel up the shaft and into the rest of the vehicle. Four repulsorlift generators carried the tank at heights of up to thirty meters while stabilizing repulsorlifts lined the tank's lower section. To result in its full gravitic force being intact upon impact, the repulsorlifts did not envelope the entire craft. This resulted in the tank being very unwieldy and slow. The seismic tank was operated from a topside command bridge by a team of battle droids. Repair droids monitored the driver, as misalignment could result in a shockwave ripping the vehicle apart. The tank totaled fifty-five meters in height. The tank was also capable of being modified for space flight and use as a dispenser of chemicals into planetary atmospheres.

Role
The seismic tank was originally used for mining purposes. When the driver would exit the channel and impact the ground, the resulting force would pulverize the terrestrial surface and expose harder minerals and metals. The tank was also used for military purposes as a form of self-propelled artillery, as the driver could be used to crush enemy forces. Modified versions of the tank could also carry chemicals used for war purposes.

History
"They're dropping something into the atmosphere. What is it?"

- Kit Fisto in regards to the seismic tanks' payload of chemicals over Ukio

Seismic tanks were a result of the skilled legal departments of megacorporations like the Trade Federation that were capable of finessing legislation passed by the Galactic Republic for the purpose of limiting the military prowess of large companies. The tank was legally designed by Haor Chall Engineering as a mining tank, and this was how companies such as the Commerce Guild were able to justify its use. However, when the galaxy-wide Clone Wars between the Republic and the Confederacy of Independent Systems (CIS) began in 22 BBY, there was no longer a need for such excuses. The first instance of the tank being used for military purposes occurred during the Battle of Dantooine. A large army of B2 super battle droids and clone troopers fought in a large open plain as a seismic tank hovered overhead. Then, to the clones' surprise, the tank dropped its driver and smashed the forces below, destroying droids and clone troopers alike. Jedi Master Mace Windu was able to fight his way into the tank and destroy it from the inside.

The second use of the seismic tank during the Clone Wars happened on the agriworld Ukio. Separatist forces were attempting to invade the planet in order to cut off major food supplies to Grand Army of the Republic. A lone Lucrehulk-class battleship deployed numerous seismic tanks into the planet's atmosphere to release a chemical designed to cling to the planetary shield operated by the locals. This resulted in a sort of portable eclipse that blocked sunlight from reaching the crops below. This forced the local liege to open the shield, allowing the CIS forces to enter the atmosphere and invade the planet. Though Jedi Generals Kit Fisto and Keelyvine Reus led a defense effort, the planet was ultimately lost to the Separatist forces.

Behind the scenes
The seismic tank first appeared in the twelfth chapter of the animated television miniseries Star Wars: Clone Wars. The episode aired on Cartoon Network on March 29, 2004. The tank received a Databank entry on StarWars.com titled "Seismic tank." The New Essential Chronology, released on October 25, 2005 and written by Daniel Wallace and Kevin J. Anderson, called the seismic tank a "seismic charge minelayer." The 2005 novel Labyrinth of Evil by James Luceno mentions the seismic tank, though not in a canon quote or thought by an in-universe character. The vehicle received an entry in the 2008 three-volume The Complete Star Wars Encyclopedia (CSWE) titled "seismic hover tank." The instance where Mace Windu destroyed a tank during the Battle of Dantooine was also mentioned in Windu's CSWE entry. The tank later appeared in the 2009 webcomic The Clone Wars: Act on Instinct.

Appearances

 * The Clone Wars: Act on Instinct
 * Labyrinth of Evil
 * The Clone Wars: Act on Instinct
 * Labyrinth of Evil