Jefferies tube

Caption: Scotty in the Jeffries tube

Star Trek: The Next Generation

Episode: TNG 245 - Lessons

Traditional name for personnel access conduits aboard Federation starships, usually to allow hands-on contact to critical circuitry and serve as emergency access in times of power outage.

In 2369, Lt. Cmdr. Nella Darren used a Jefferies Tube junction on the Galaxy-class Enterprise as a concert hall for its acoustics.