A typical ship of this type had two outboard nacelles and an inboard nacelle. These nacelles were connected by swept pylons to the underside of the primary hull. Similar to the Miranda-class starship in the prime reality, an Armstrong-type starship was equipped with a rollbar module. Extending from the trailing edge of the primary hull, and connected to the rollbar by smaller pylons, there was a structure housing the impulse drive.
USS Excelsior (NCC-1729) (β) was depicted in concept art from Star Trek - The Art of the Film as a brown colored ship of this class. According to the novelization of Star Trek, the Excelsior also participated in the Battle of Vulcan.