Transwarp is a general term meaning any transportational speed that exceeds that of traditional warp drive limits. By the 24th century, this would mean speeds in excess of warp factor 9.9 (which is 3053c), a speed a Soverign-class vessel could sustain for only a few hours. Transwarp speeds can be measured in the same factors as normal warp to draw comparison, though the speeds increase exponentially up to warp 10 which is infinitely fast, drawing its own bizarre consequences. (VOY: "Threshold")
Transwarp speeds could be attained naturally by a wormhole or transwarp conduit for example. However, artificial generation of transwarp speeds would be a great technological advantage to any race. Very few races were known to be capable of achieving transwarp speeds by the 24th century, two of them were the Borg and the Voth. In 2370, Geordi La Forge of the Enterprise-D commented that the Rebel Borg ship's transwarp drive was like "falling into a fast-moving river and getting swept away by the current." (Star Trek: First Contact; VOY: "Distant Origin"; TNG: "Descent")
The Federation attempted to achieve transwarp speeds in an experiment involving a new drive installed on the USS Excelsior in 2285. It ultimately proved unsuccessful. An anomaly found in 2374 that was able to, among other things, shrink a runabout to a few centimeters gave Starfleet hope and inspired them to make further attempts at creating a transwarp corridor; however, these too ultimately failed. ("Star Trek III: The Search for Spock"; DS9: "One Little Ship")
Quantum slipstream, developed by Species 116 is another method of propulsion that is analogous to transwarp, achieving the stability transwarp drives could not. (VOY: "Hope and Fear")
See also
- Quantum slipstream drive
- Transwarp aperture
- Transwarp corridor
- Transwarp drive
- Transwarp Evolutionary Syndrome
- Transwarp hub