Transwarp and the tranwarp drive were an experimental technology for increasing the efficiency and speed of starship propulsion systems. Though the project showed great promise and was extensively tested on the USS Excelsior, Federation scientists could not make it work successfully and abondoned the project. An artificially-created subspace tunnel known as a transwarp conduit was used by a Borg ship of unusual and previously unknown design in 2369. The transwarp conduit was capable of defying normal subspace limitations and allowed maximum speeds up to twenty times faster than a Galaxy-class starship. This series of transwarp conduits was accessed by an encoded high-energy tachyon pulse ("Descent, Parts One and Two" [TNG]). A rare form of dilithium called trilithium was used by the Voyager crew in an attempt to recreate the original transwarp experiments. Unfortunately, Voyager's tests ended in abject failure. The reason for this being the sudden and spontaneous occupation of every point in the universe when an object reached warp 10, the theoretical barrier of warp drive. There is speculation that the original transwarp drive was an attempt to create an opening via interphase and travel through another dimension. Since time flowed at a different rate in this other dimesion, a three week journey via real space would only take three days in interspace; however, this is only a stop gap measure and creates unpleasant scenarios akin to the relativity problems of non-warp interstellar travel. Other theories include the possibility that the tranwarp conduits act as containment fields, much like the transporter's annular confinement beam. This containent field would maintain the integrity of the object and keep it from spreading out to occupy every point in the universe. Only the Borg are known to have this technology and have actually demostrated the technique to Federation observers on several occasions.
