The fifth USNS Potomac (T-AO-181) was a United States Navy oiler in non-commissioned service with the Military Sea Transportation Service, later Military Sealift Command, from 1976 to 1983. Potomac, sixth U.S. Navy ship to bear the name, was laid down as SS Shenandoah at Sun Shipbuilding and Drydock Company at Chester, Pennsylvania, on 1 March 1964 and launched on 10 October 1964. She was built using the 200-foot (61 m) salvaged stern section of the oiler USNS Potomac (T-AO-150)—a ship which had been destroyed by a fire on 26 September 1961—to which a new forward section was added. She was the first ship equipped with an offshore petroleum discharge system (OPDS), allowing her to supply petroleum products to forces ashore by pumping it directly over the shore instead of having to deliver i