The T'Plana was a Vulcan starship that was in service with the Vulcan High Command in the mid-21st century. The T'Plana and its crew were destroyed when it failed to outrun a class 5 neutronic storm. Details of this incident were recorded into the Vulcan database carried aboard NX-class starships.
In 2152, Sub-Commander T'Pol mentioned this incident to Captain Archer when Enterprise NX-01 encountered a similar phenomenon. (ENT: "The Catwalk")
In an earlier draft, the vessel was known as the T'Plana-Hath, in honor of the matron of Vulcan philosophy. However, the name was shortened during production.