Jefferies tube

Jefferies tubes are maintenance and access tubes in most Starfleet vessels. Through these tubes engineering crew can access ship systems for repair or maintenance. In the event of emergencies or when the turbolifts are not operational they can be used to navigate around a vessel.

During a war game between the USS crew and the Starfleet Marine company stationed onboard both sides made use of the Jefferies tubes to move their forces around the ship.

After the failure to eject their warp core, Lieutenant Commander Pavlo Celcho led a three person engineering team through the Jefferies tubes of the USS Swiftfire-A to attempt to clear the damaged core from the vessel.