Quake tower

Quake towers (also Earthquake towers or Shockwave towers) were a powerful sonic/seismic weapon invented on the planet Yavia by Yavian warlords and used extensively on that world. Due to their unique effectiveness, they were widely exported to other places throughout the galaxy.

Technology
Quake towers consisted of a massive weight and a pulley system that would lift and then release the weight. The weight fell into a precicely crafted socket filled with electrostatic material. The force of the impact was enhanced by the sockets shape and the magnetic stress, creating a massive shockwave. This shockwave traveled through the ground and through the air, and could seriously injure troops and damage vehicles.

History
Quake towers were originally developed in the Yavian inferno, many centuries before their first use outside that subterranean environment. The towers were more effective than usual in the inferno, since their shockwaves often caused lava to spew out of fissures in the ground, as well as causing rockfalls and igniting volatile gases.

Quake towers were first properly introduced to the surface dwellers of Yavia in 2000 BBY, after the war against Moloch. They have since been exported to other worlds for use by many militant groups. They were used on Geonosis before and during the Clone Wars. They have also been found in the hands of the Galactic Empire.

Quake towers were considered barbaric and uncivilized weapons, and were outlawed by both the Old Republic and the New Republic.