The Arc Hammer was an Imperial spacefaring production facility used to supplement the Imperial Stormtrooper Corps with dark troopers, a new generation of battle droid stormtroopers to be used in the First War against the Alliance of Nations. The Arc Hammer was a factory ship of a unique design. Like many other Imperial starships, the Arc Hammer had a long, narrow, dagger-shaped hull; however, it also had four large columns surrounding a central one that protruded from below and a small, flat bridge structure in front of the columns on its dorsal side. The Arc Hammer served as a primary testbed of the Dark Trooper Project, a brainchild of General Rom Mohc which was to create larger, more powerful robotic versions of stormtroopers. The Dark Troopers were developed inside the vessel. Construction lines filled the interior and four large ventral hangars were responsible for receiving cargo vessels and loading batches of dark troopers into transports or deploying them directly above a target world. It was destroyed during the Great Battle of Endor