SS Cape Island (AKR-10) was originally laid down for commercial service in 1976 as Illinois, a Type C7 ship for the States Lines. It was launched and then needed to be used for military service transferred into the Naval Vessel Register (NVR) as the USNS Mercury, as transport ship for vehicles, and other goods.  In 1993 the ship was permanently transferred to the navy's roll as a ready reserve ship, and renamed Cape Island (T-AKR-10). Wikipedia

SS Cape Intrepid (AKR-11) was originally laid down in 1975 as SS Arizona a Type C7 ship intended for both commercial or military use. The ship was launched in 1975 and turned over to the Maritime Administration and named the SS Lipscomb Lykes. On June 8th 1976 she was reacquired by the United States Navy and renamed USNS Jupiter. On 8 June 1976 she was transferred to Military Sealift Command, and renamed the SS Cape Intrepid.  Since then the ship has been active in transport roles including a long term attachment to the 833rd transport regiment. Wikipedia

Both The Cape Island  and The Cape Intrepid remain laid up in ready reserve state so that it may be activated in 5 days, if called upon. READY RESERVE FORCE "RRF"