USS Granville S. Hall (YAG-40), 1953-1972. Originally named YAG-40
The "Liberty" ship Granville S. Hall, built at Panama City, Florida, in 1944, was operated as a commercial freighter until June 1952, when she was laid up at Suisun Bay, California. About a year later, she was converted to a U.S. Navy vessel, designated YAG-40. Following completion of this work, the ship was placed "in service" and employed for scientific support work in the Pacific. Among her duties was the exploration of radioactive fallout patterns during nuclear weapons testing in the Marshall Islands area. Late in 1957 YAG-40 was taken out of service and enered the Pacific Reserve Fleet at San Diego, California.
Reactivated in May 1962, the ship was placed in commission in October of that year and, at about the same time, regained her original name, becoming USS Granville S. Hall (YAG-40). During the remainder of the decade, she served in connection with Project SHAD ("Shipboard Hazards & Defense"), an investigation of the threats posed to Navy ships by chemical and biological agents. This mission ended in the early 1970s and, at the beginning of May 1971, USS Granville S. Hall was stricken from the Naval Vessel Register and turned over to the Maritime Adminsitration. She was sold for scrapping in March 1972.
The SS Granville S. Hall was named in honor of Dr. Granville S. Hall (1844-1924), a pioneer in the academic study of psychology. That name was reapplied when the Navy reactivated the ship in the early 1960s.
....Notice the forward mast with the dish under it, designed to 'catch' fallout?