Retired Rear Adm. Robert Emmett Cronin, 76, a former chief of industrial relations for the Navy and a professor-emeritus of engineering and applied science at George Washington University, died of cardiac arrest Sunday at the Potomac Valley nursing home in Potamac.

Adm. Cronin was born in Kankakee, Ill. He graduated from the U.S. Naval Academy at Annapolis in 1925 and earned a master's degree from Columbia University in 1932.

After graduation, Adm. Cronin served on various ships and then returned to the Academy as an instructor in engineering. He was engineering officer aboard the battleship Maryland when it was damaged in the Japanese attack on Pearl Harbor on Dec. 7, 1941.

In 1942, adm. Cronin began a series of assignments in the building of ships that occupied him for the rest of his career.

He was assistant planning officer and machinery planning superintendent at the Norfolk Navy Yard in Portsmouth, Va., and from 1945 to 1949 was head of the electrical section at the Bureau of Ships in the Navy Department. He was planning officer of the Boston Navy Yard from 1949 to 1952 and commander of the Portsmouth (N.H.) Navy Yard from 1952 to 1954.

Adm. Cronin returned to Washington in 1954 and was assistant chief of the Bureau of Ships until 1956, when he was named chief of industrial relations for the Navy. He served in that post until his retirement from the service in 1961.

He then joined the faculty at George Washington. He was named professor-emeritus in his specialty in 1971.

Adm. Cronin, who lived in Bethesda, was a member of the American Society of Naval Engineers, the Society of Naval Engineers, the Society of Naval Architects, the Pearl Harbor Survivors, the George Washington Univeristy Club, the John Carroll Society, the Naval League, and the Church of the Little Flower in Bethesda.

Survivors include his wife, the former Carolyn Jane Cobb, of Bethesda; a son, Robert E. Jr. of Minneapolis, Minn., a daughter, Carolyn Posey, of Alexandria; a sister, Frances Cronin, of Mattoon, Ill., and seven grandchildren.