High Quality Content by WIKIPEDIA articles! USNS Comfort (T-AH-20) is the third United States Navy ship to bear the name Comfort, and the second Mercy Class Hospital Ship to join the navy fleet. The USNS prefix identifies the Comfort as a non-commissioned ship owned by the U.S. Navy and crewed by civilians. In accordance with the Geneva Conventions, USNS Comfort and her crew do not carry any ordnance and firing upon the Comfort is considered a war crime. Like her sister ship USNS Mercy (T-AH-19), Comfort was built as an oil tanker in 1976 by the National Steel and Shipbuilding Company. Her original name was SS Rose City and she was launched from San Diego, California.