Type 1

The TARDIS design was an early prototype created by the elders of ancient Gallifrey. It was poorly designed, dangerous, and hard to start. Some of them had minds of their own, with a history of escaping and roaming the Universe. (PDA: Heart of TARDIS)

The Time Lords believed a Type-one had broken into a dangerous time-zone, but it turned out to be the Second Doctor. (PDA: Heart of TARDIS)