The Incomplete ship is a makeshift spaceship constructed by cloned Goa'uld in Steveston, Oregon.
Overview
The ship itself does not resemble any known Goa'uld design previously encountered by the SGC, which might be due to the fact that it was built using Earth materials. It is thus unknown what technology was included into the ship, although it can be assumed that it at least possesses a hyperdrive.
History
When Adrian Conrad purchased a Goa'uld, the symbote was cloned many times. These symbiotes were eventually able to take over nearly the whole town of Steveston. Since the symbiotes were clones, they could only take control over their hosts at night when they were sleeping. Deciding to unite with their brethern in the galaxy, the symbiotes began to build a spaceship inside an abandoned shipyard. They worked on it for over three months but secretly the NID had been monitoring their activities and planned on capturing the vessel once it was complete.
About ten months after the Conrad incident, the SGC began to examine the town after a former worker of Conrad warned Major Samantha Carter. Carter, Teal'c and Jonas Quinn eventually found the ship but were captured by the Goa'uld, as well as the two NID agents who were undercover in the city. One of the agents was then implanted with a symbiote who in turn should implant the remainder of the NID. Luckily, after SG-1 managed to kill the symbiotes with a kill switch, the vessel was taken to Area 51 for further study. (SG1: "Nightwalkers")
The ship's Schematics.