saucer-like primary hull and elongated warp nacelles in pairs. The Akira class featured the traditional saucer section and nacelles combined with a catamaran-style double hull; the Norway class was based on the USS Voyager; the Saber class was a smaller ship with nacelles trailing off the tips of its saucer section; and the Steamrunner class featured twin nacelles trailing off the saucer and connected by an engineering section in the rear. Each design was modeled as a three-dimensional digital wire-frame model for use in the film. The film also required a number of smaller non-Starfleet designs. The warp ship Phoenix was conceived as fitting inside an old nuclear missile, meaning that the ship's nacelles had to fold into a space of less than . Eaves made sure to emphasize the mechanical aspect of the ship, to suggest it was a highly experimental and untested technology. The Phoenixs cockpit labels came from McDonnell-Douglas space shuttle manuals. Eaves considered the Vulcan ship a "fun" vessel to design. Only two major Vulcan ships had been previously seen in Star Trek, including a courier vessel from The Motion Picture. Since the two-engine ship format had been seen many times, the artists decided to step away from the traditional ship layout, creating a more artistic than functional design. The ship incorporated elements of a starfish and a crab. Because of budget constraints, the full ship was realized as a computer-generated design. Only a boomerang-shaped landing foot was fabricated for the actors to interact with. The Enterprise interior sets were mostly new designs. The bridge was designed to be comfortable-looking, with warm colors. Among the new additions was a larger holographic viewscreen that would operate only when activated, leaving a plain wall when disabled. New flatscreen computer monitors were used for displays, using less space and giving the bridge a cleaner look. The new monitors also allowed for video playback that could simulate interaction with the actors. The designers created a larger and less-spartan ready room, retaining elements from the television series; Zimmerman added a set of golden three-dimensional Enterprise models to a glass case in the corner. The observation lounge was similar to the design in the Enterprise-D; the set itself was re-used from the television show, the only such set not to be struck following the filming of Generations, though it was expanded and underwent a color change. Engineering was simulated with a large,