Power Transfer Conduit
On a Federation Starship, a Power Transfer Conduit (abbreviated PTC) is an advanced type of Plasma Conduit, used for carrying warp plasma from the vessel's Warp Core to the drive Nacelles. The conduits are magnetically shielded against the superheated warp plasma, and are roughly 0.6 to 1 meter in width.
Characteristically, the conduits emerge from the equatorial region of the Matter-Antimatter Reaction Chamber of the warp core, and from there travel aft through the ship until they turn 90 degrees, to port or starboard, through the nacelle pylons, before terminating in the Plasma Injectors and the warp plasma they are carrying is transfused into the Warp Coils.
Along with carrying the warp plasma, the power transfer conduits also contain manifold links to the Electro-plasma system (EPS), where electronic energy is bled off from the warp plasma in the form of microwaves, providing electrical energy for the vessel.
In the USS Enterprise-D, (Star Trek: The Next Generation) the power transfer conduits can be entered for inspection. Chief Engineer Geordi La Forge performed an inspection in the company of Dr. Leah Brahms from the Daystrom Institute of Technology during her technological inspection of the Enterprise, which she helped design. (TNG: "Galaxy's Child") During such an inspection, safety concerns would apply, of course.
In the warp drives of Intrepid Class starships, including the USS Voyager, the power transfer conduits were not immediately visible in engineering, so it is easily assumed that they were below the deck. However, they seem to have been easily accessible, since a transwarp mutated Lieutenant Tom Paris once managed to use a hand Phaser on one of the transfer conduits of Voyager, causing power failures all over the ship. (VOY: "Threshold")
When the Magnetic Constrictors lost alignment on Voyager in 2372, B'Elanna Torres asked Michael Jonas if he adjusted the power transfer conduits. Doing so, with no effect, Torres noted to Jonas to not let the PTC temperature go above 3.2 million Kelvin. (VOY: "Investigations")
