Barney joined the Navy's V-12 program while still an undergraduate at Franklin Marshall College in Lancaster, PA. Under the Navy's tutelage, he studied medicine and surgery at Jefferson Medical College, Philadelphia, PA. At the outbreak of World War II, he attempted to resign from the Navy and enlist in the Army, but higher-ups told him that the country needed doctors as much as it needed fighting troops. He finished his medical education just as the war was ending.Between World War II and Korea, he was stationed at the Philadelphia Naval Hospital. In addition, he served tours of duty on the U.S.S. New Jersey and the U.S.S. Midway. When the Korean War began, he was assigned to the U.S.S. Haven, a hospital ship stationed at Inchon Harbor, South Korea.
In 1954, the Haven was ordered to sail from Korea to unknown destination and given sealed orders to be opened at sea. When the orders were opened, they were in French, and Barney, a Lt. Commander at the time, was the only officer on board who could read French. The Haven was directed to Saigon, where it evacuated French casualties from the battle of Dien Bein Phu and transport them to Algeria for repatriation.Barney's next duty station was Great Lakes, IL, where he served as chief of the dependent service in the base hospital. In 1956, he left the service.