This article needs a big cleanup.
The image is of the Vardans' ship, or at least the one they appeared on. Were the Sontarans also using that ship?
These problems might be so great that the article's factual accuracy has been compromised. Talk about it here or check the revision history or Manual of Style for more information.
The Sontaran Assault Ship was used by the Sontarans in their invasion of Gallifrey. (DW: The Invasion of Time)