Time corridor
A time corridor, also called a spacetime-induction channel and sometimes referred to as a time tunnel, was a form of time travel in which a wormhole was created through the Time Vortex. It was generally considered less advanced than other time travel technologies such as TARDISes. (TV: Timelash)
The Time Vortex was also referred to as a time corridor (PROSE: Timewyrm: Revelation) which may have accounted for the danger of creating other corridors through the Vortex. Kontron tunnels were time corridors in space rather than the Vortex. (TV: Timelash)
Time corridors were primarily used by the Daleks. Despite being described as less advanced than other time technology, time corridors seemed to be easily capable of dragging a TARDIS off course to a specific location. (TV: The Evil of the Daleks, Resurrection of the Daleks, Remembrance of the Daleks)
Time corridor technology was first used by the Daleks near the beginning of the Great Civil War. (TV: The Evil of the Daleks)
In order to complete a corridor, the Daleks built time conduits that would serve as the ends of the corridor. If the conduit on a planet was destroyed, the Daleks would no longer be able to reach it via the time corridor. (AUDIO: The Mutant Phase) The Daleks used a time corridor as a link between themselves and Earth in 1984. There they had deposited samples of the Movellan virus that they would later need. Turlough accidentally travelled through the corridor and so the Doctor followed him in his TARDIS. Both the Daleks and Lytton's men used the corridor numerous times. (TV: Resurrection of the Daleks)
One Dalek ship containing three Daleks escaped the destruction that the Meta-Crisis Doctor caused in Davros' New Dalek Empire and travelled to 1941 by using a time corridor. The New Dalek Paradigm that was created by these survivors similarly escaped through a time corridor after their plan to destroy Earth in 1941 failed. (TV: Victory of the Daleks)
The Sontarans were also developing time corridor technology, constantly improving their advancements whereas the Daleks, at least according to the Sontarans, assumed they achieved perfection and so did not improve their methods. (AUDIO: The Five Companions)
In emergencies, some crafts travelling within a time corridor could deploy an escape time corridor which could latch onto familiar technology. (AUDIO: The Time of the Daleks)
The fractured Eternity Clock created time corridors in four different eras of London, releasing the Silence in the Elizabethan Era, Silurians in the Victorian Era, Cybermen in modern day London and the New Dalek Paradigm in 22nd century London. The Eleventh Doctor and River Song travelled between these different times and collected the pieces of the Clock, which closed the time corridors and erased the alternate timelines created by the invading species. (GAME: Doctor Who: The Eternity Clock)
The Eleventh Doctor accidentally jettisoned a room once, accidentally creating a time corridor, allowing shadowy creatures to pass through and arrive in 1964. They were drawn to Earth because Ethan dropped his mobile phone in 1964, despite coming from 2014, which made them hungry. (COMIC: The Door to a Winter Long Ago)
Behind the scenes
According to the invalid source, Doctor Who: The Dalek Handbook, after the end of the civil war and the defeat of the Humanised Daleks, the Emperor Dalek decided that the Daleks, in order to succeed in their conquests, would have to change history, thus time travel was put into greater use by the race.
