Galaxy class

 was a rating for a passenger starship. Large and luxurious, they could go for years between landfall and typically could produce their own air.

The Thrasymachus was a Galaxy Class starliner on which Amy Pond and Rory Williams honeymooned. It almost crashed until the Eleventh Doctor and Kazran Sardick had Abigail Pettigrew sing the skies calm. (DW: A Christmas Carol)

The Byzantium was a Galaxy Class starship that Weeping Angels crashed on Alfava Metraxis. (DW: The Time of Angels)