Type 91

A Type 91 or 91-form timeship (PROSE: The Brakespeare Voyage) was a type of War TARDIS. (PROSE: The Taking of Planet 5, The Book of the War)

They were created by the Time Lords to fight the Great Vampires, (PROSE: Doctor Who and the Krikkitmen) and they were used heavily during the War in Heaven. They were intentionally designed to stand out and appear big and bulky. They would sometimes become stuck on planets and become embassies for the Great Houses. (PROSE: The Book of the War)

Type 91 TARDISes were part of the Eleventh General's strike force during the Last Great Time War. (PROSE: The Third Wise Man)