Type 12

Type 39 was a type of TARDIS used by Time Lords. It was a much older model than the Type 40 used by the Doctor. Professor Chronotis owned a Type 39 TARDIS, which served as his rooms at St Cedd's College, Cambridge. This TARDIS model could hold another TARDIS within its force field and create a bridge between the two to walk through. Type 39 TARDISes were capable of interfering in an individual's time stream. It either did not have a chameleon circuit, or his didn't work. (DW: Shada)