Four ships of the United States Navy have been named Ajax, after Ajax, a Greek hero during the Trojan War.
USS Ajax (AR-6) was the second Vulcan-class repair ship and the fourth ship in the United States Navy to bear the name.
Ajax was laid down on 7 May 1941 at Los Angeles Shipbuilding and Dry Dock Company, San Pedro, California, launched on 22 August 1942; sponsored by Mrs. Isaac C. Johnson commissioned on 30 October 1943, Comdr. John L. Brown in command.
The repair ship departed San Pedro on 9 December, arrived at Pearl Harbor on 16 December, and began preparing small craft to be used as control vessels in the Marshall Islands campaign by installing radar, sound detection equipment, and antiaircraft guns. On 8 January 1944, an oil fire in her blacksmith shop threatened the entire ship, but was extinguished. Nevertheless, Ajax spent part of January repairing her own damage.
On 25 January, Ajax was ordered to proceed in company with Wadleigh (DD-689) to the Ellice Islands; but, two days after reaching Funafuti, she moved to Makin Atoll, Gilbert Islands, to work on the ships that would occupy Majuro in the Marshall Islands. Upon completing that mission, the ship returned to Funafuti on 26 February, only to sail three days later for Majuro.
The second USS Rockport SP-738 was built during 1917 and 1918 by Adams Shipbuilding Co., East Boothbay, Maine, as the wooden scientific research vessel Ajax for service in Labrador waters and acquired 2 October 1917 for U.S. Navy service from A. Fabbri of New York, while still under construction. Commissioned 16 February 1918, Ens. Charles W. Farmer, USNRF, in command, Ajax was renamed Rockport 20 February 1918.
Rockport was reassigned to the 1st Naval District 1 January 1918 and operated on section patrol duty based at Boston into 1919. She decommissioned 18 February 1919 and was sold 16 September 1919 to Thomas S. Longridge of Belmont, Mass.