Type 91
From Tardis Wiki, the free Doctor Who reference
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. (PROSE: The Book of the War)
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)