The Doctor's Battle TARDIS

From Tardis Wiki, the free Doctor Who reference

The War Doctor was forced to use a Battle TARDIS for a time during the Last Great Time War instead of his usual TARDIS, in an attempt by Time Lord agent Veklin to make him more controllable. The ship was connected to the Doctor's heartbeats, being set to self-destruct if he died.

Whilst travelling in this ship, the Doctor rescued Albert Brown from the Gallipoli campaign and went to Carter Baross where he, Veklin and Albert found a berserker-class cyborg, Case. He finally used it to investigate a distress signal he correctly suspected came from a disguised Dalek harvester. When he and Case hijacked the vessel, the ship's Supreme threatened to overload the storm drive to destroy the entire solar system around them so the Doctor briefly stopped his own hearts to trigger the Battle TARDIS' self-destruction, destroying the storm drive and setting the harvester on a collision course with the planet Tharius. (AUDIO: Saviour)