The Type 390 Trebuchet was developed for the second attempt at recapturing Epsilon Eridani e/Tierados, the first human colony to declare independence from Earth in 2280 after the first invasion failed due to the heavy fortifications present on Tierados. Cities and other important areas on Tierados are protected by large shield generators capable of intercepting any projectile or vehicle attempting to break through. The only way to bring these shields down is by bombarding them until they overload, and the Trebuchet is built to do exactly that.
It's designed for high endurance, as such it's powered by two redundant microfusion reactors and has a built-in smelter to produce ammunition if needed. It's protected by heavy ceramic-graphene composite armor, with interior graphene spalling blankets as well as an active defense system capable of intercepting even small to medium caliber railgun rounds.
Its armament consists of a single hybrid cannon that functions like a regular 150mm electrothermal-chemical cannon while mobile, and transforms into a chemically assisted railgun when it deploys into siege mode. It also has a twin 40mm autocannon turret on the top, and two non-nuclear shield-breaking missiles.