RHTT-7-A "Earthshaker". image - The Second Clone Wars mod for Star Wars: Empire at War: Forces of Corruption

During the entire Clone Wars, CIS orations were always hampered for lack of dedicated heavy artillery. Sure weapons like the HAG supported the infantry advance and shipborne artillery and bombers worked on siege well enough, but for some reason the CIS never developed something in between to provide their infantry with solid heavy fie support at a relatively cheap cost. This also meant the troops on the ground were left without heavy artillery support in the event the enemy achieves space or air superiority. Zann, along with his first Lieutenant Urai Fen notice this sever handicap while rebuilding the Separatist war machine and sought to correct it.

They started with the base of a Baktoid Armor Workshop's RHTT-6 transport and begun experimenting with various weapon mounts in its cargo compartment. Initially, it was planned to be equipped with a pair of heavy Turbolaser but the massive power requirement made the idea impractical. Then it was equipped with two giant 90cm mass drivers which prove much more practical but the immense recoil made the first prototype to flip over. This was corrected with a reverse repulsion mechanism taken from the venerable UT-AT, with allowed the repulsors to reverse their repulsion, causing gription fields hence allowing them to pin themselves onto the ground. This meant the gun can only fire on one direction at a time and has to redeploy to fire in other direction. Early in the development, the unit was meant to have an open top. However, it was later decided to add a pair of protective shield over the gun to minimize it damage from counter battery fire. This decision also resulted in an unforeseen benefit as the new configuration in its undeployed from look exactly like a harmless RHTT-6 transport.