Dean R. Koontz wrote a novelization of the screenplay under the pseudonym Owen West. The book contains a lot of backstory added by Koontz and because of this, and the fact that the book was released before the movie due to a delay in post production, it is often mistaken that the movie is based on the book, when the reverse is true.
Tobe Hooper re-used some of the film's props when he directed the music video for Billy Idol: Dancing with Myself (1983).
Director Tobe Hooper was at one point nearly struck by a flying cog but was saved by an extra who broke their arm in the process.
Steven Spielberg asked Tobe Hooper to direct "E.T., l'extra-terrestre (1982)" but he turned it down because he was busy on this movie. Hooper and Spielberg would later work together on "Poltergeist (1982)."
An accident occurred during filming when a carnival ride carrying several passengers was left on for about twenty minutes to half an hour. The ride, which has several octopus arms that spin around with rotating carriages, normally only runs for about four minutes per joyride. Thrillseekers vomited and yelled out real screams as the ride continued way past its end time. When stopped, the riders could not walk and were somewhat twisted in their musculature. An ambulance was called but no one was seriously injured.