The Thunder started out as a Alliance tank then as a New Republic Tank, seeing some of the worst ground campaigns during the civil war and other battles. When its service time came to an end Caden bought the tank instead of it getting recycled. The Tank was then converted into a repulsor tank with heavier weapons and modified systems. Caden working off of Thunder's plans developed a more economical version which he sold to the republic. The Thunder would then become the father for all the T3-BHs that are built.