sentences:  On June 1, 1943, two officers, one warrant officer and 44 enlisted men began intensive training at Vint Hill Farms to man Radio Marina.In December, 4 officers and 50 enlisted men staffed Radio Marina, a base located on an arrowhead-shaped tract of land, designated as Tract A by the U.S. Military.While the United States had access to base since 1942, a formalized agreement to permit the United States use of the site did not exist until 1952 when the Ethiopian government, the federation of Eritrea and the United States signed an agreement.