Wikipedia: link
In the programme, the Doctor's TARDIS is an obsolete "Type 40 TT capsule" that he unofficially "borrowed" from the repair shop when he departed his home planet of Gallifrey. He was stopped while following Susan into a TARDIS, by Clara Oswald who opined that he was about to make a terrible mistake and advised him to instead take the adjacent unit. She explained that second ship's navigation system was malfunctioning but he would have much more fun with it.[21]
Tardis Data Core: link
When the Doctor first decided to leave Gallifrey, he had the chance to take a Type 53, but dismissed it as "soulless" in favour of the Type 40. (PROSE: Lungbarrow) although he did receive a recommendation for the Type 40 from a mysterious young woman. (TV: The Name of the Doctor) The TARDIS herself said she was "a museum piece", though this may have been figurative. (TV: The Doctor's Wife)
Assim, os Tardis se referiram a si mesmos como uma peça de museu, significando uma relíquia, antiga, obsoleta.