The Spiral-class Assault Ship is a small needle-shaped craft that is specifically designed to quickly insert an assault team to seize control of a targeted ship or station. This single-use only ship is designed to only penetrate non-military vessels or space stations. Once the Spiral's proton charge has detonated on the target's particle shields, it passes through the temporary breach to burn through and bury itself into the target's hull. This assault ship was in service at least after the introduction of the Lancer Frigate into the Imperial Navy.

    Upon collision, the Spiral's nose cone vaporizes, and absorbs nearly 92 percent of the kinetic energy of the impact. Thus insuring the ship's cabin remains virtually intact. Additional protection to the special forces troops and crew is supplied by inertial-damping grav couches. Over 70 percent of the craft is dedicated to the subspace engines and shield generators, giving it power but no grace. Cargo space onboard the craft is severely limited, each trooper can only carry a few small items in an overhead bin and not much more in the rear cargo compartment. Once onboard, vac-suited troopers debark and overwhelm the stunned crew of the target. The target is captured before its crew knows what hit them.

    Unfortunately, the Spiral-class Assault Ship is also used by the Rebellion, since they have been able to capture some of these ships. The most notable use of these ships by the Rebels was their capture of the Container Train Black Ice after the Battle of Yavin.