Transwarp coil
A transwarp coil was a propulsion device which allowed Borg vessels to generate a transwarp conduit. ()

To generate a transwarp conduit the coil required a minimum input of thirty teradynes (three hundred meganewtons) of force from the ship's systems. On Borg vessels, the coils were protected by a protocol that damaged the coil beyond repair by fusing the field regulator when the vessel became critically damaged. ()

In 2153, the two researchers  and  discovered a transwarp coil from the wreck of a Borg sphere that crashed in Earth's Arctic Circle. ()

In mid-2375, after surviving a battle with a Borg probe, the crew of the  managed to recover several Borg data nodes containing, among other information, long-range sensor telemetry and vessel movements for a radius of thirty light years. Utilizing this information, Voyager was able to locate a damaged Borg sphere and steal a working transwarp coil from the ship's transwarp chamber. The coil was fitted to both the  and Voyager itself, providing twenty thousand light years of travel before giving out, shaving approximately fifteen years off Voyagers journey home. ()

See also 
Driver coil
Plasma coil
Primary drive coil
Resonator coil
Warp coil
Primary warp coil
Teraphasic coil

de:Transwarpspule
fr:Bobine de transdistorsion
Coil
Borg technology