Transwarp conduit

The topology of a transwarp conduit

The rogue Borg ship enters a transwarp conduit

A transwarp conduit was an artificial construct that could be used to achieve faster-than-light travel, in a similar fashion to a wormhole. Vessels traveling in such conduits can traverse vast distances in a matter of hours at speeds estimated to be at least 23times faster than 23rd century alliance warp factor [Chief engineer LaForge]. The Borg used this technology extensively.

A Borg transwarp conduit was first observed in the 2350s by the USS Raven. The opening of a conduit was characterized by triquantum waves, subspace disruptions with a field magnitude exceeding 2.9 teracochranes, and a symmetric power utilization curve. Inside the matter stream of the conduit, ships were accelerated to move forward. (VOY: "Dark Frontier")

The second time a transwarp conduit was observed occurred in 2369, by the USS Enterprise-D, during the pursuit of a rogue Borg ship. It was discovered that a conduit could be re-opened with a high-energy tachyon pulse emission on a specific tachyon frequency matrix that alternated between the low and secondary bandwidth frequencies. A closed mouth of a transwarp conduit was discovered to exhibit net external subspace transwarp distortions that fluctuated between 30 and 288 millicochranes. (TNG: "Descent")

Later discoveries by the USS Voyager during its journey in the Delta Quadrant revealed that the Borg maintained a vast network of transwarp conduits, allowing the Collective to reach any region in the galaxy. One such conduit opened within a light year of Earth. This conduit brought Voyager back to the Alpha Quadrant after its disabling of the transwarp hub. (VOY: "Endgame")

Conduits could be generated using The Borg transwarp drive, a technology that shared similarities with the quantum slipstream drive of Species 116. (VOY: "Hope and Fear") Such conduits were utilized by Voyager in 2375, after the capture of a transwarp coil. Using the coil, the Delta Flyer was able to open a conduit to Unimatrix 01. Upon its return, Voyager destabilized the conduit by sending a spread of photon torpedoes into the opening, destroying the Borg Queen's vessel that was still inside. The starship then used the coil to generate a conduit a further 20,000 light years towards the Alpha Quadrant. (VOY: "Dark Frontier")

In 2374, Seven of Nine attempted to generate a transwarp conduit by modifying the Voyager's main deflector to emit tachyon bursts. Unfortunately the experiment proved disastrous, as the transwarp frequency emissions caused a pressure increase in the warp core, flooding it with tachyons and nearly causing a breach. (VOY: "Day of Honor")

According to the videogame Star Trek: Armada II, the Borg also had the technology to generate conduits using transwarp gates (Borg transwarp gate at Memory Beta, the wiki for licensed Star Trek works) and transwarp portals (Borg transwarp portal at Memory Beta, the wiki for licensed Star Trek works).