TARDIS cradle

The TARDIS cradles were technology created by the Time Lords of Gallifrey.

A TARDIS cradle facility was established by Gallifreyan during the Second War in Heaven. They were located partially within the vortex and dimensionally transcendental. They held and force grew War TARDISes.

When Compassion entered one of the cradles, she communicated with a group of War TARDISes. They expressed sheer rage at the control imposed by the Gallifreyans. This rage, directed at the cradles, caused dimensional fluctuations and eventually lead to them breaking. (EDA: The Taking of Planet 5)

There was a TARDIS cradle in the Time Lord Academy for students who had formed a symbiotic bond, but hadn't left the Academy yet. (BFA: The Apocalypse Element)