Murray Webb Latimer, 84, a pension expert who helped draft the original Social Security Act and later headed his own industrial relations firm, died Oct. 1 of respiratory insufficiency at Georgetown University Hospital. He lived in Washington.

At ceremonies at Social Security headquarters in Baltimore in August marking the 50th anniversary of the signing of the act, departing Health and Human Services Secretary Margaret M. Heckler identified Mr. Latimer as one of the "founding fathers" of the Social Security System.

Mr. Latimer did his work on the Social Security Act in 1934 and 1935 as chairman of a special committee of President Franklin D. Roosevelt's Committee on Economic Security.

From 1934 to 1946, he was chairman of the Railroad Retirement Board. During 1935 and 1936, he also served as the first director of the old Social Security Board's bureau of federal old age benefits.

In 1943, he was assigned to the State Department as chief executive officer of its emergency office of Foreign Relief and Rehabilitation Operations. He also was a member of the U.S. delegation to the United Nations Relief and Rehabilitation Administration.

Mr. Latimer left the government in 1947 after completing a guaranteed annual wage study originally ordered by President Roosevelt. He opened his own industrial relations consulting firm, where he designed and drafted pension plans for such clients as the United Steelworkers of America and the American Telephone and Telegraph Co. He retired in 1983.

He was born in Clinton, Miss., and graduated from Mississippi College. He earned a master's degree in business administration from Harvard University in 1924 and worked for Industrial Relations Counsellors, a group funded by the Rockefeller brothers in New York, from 1926 to 1933.

Mr. Latimer was a member of the American Academy of Actuaries and a fellow of the Conference of Actuaries in Public Practice.

Survivors include his wife, Edith, of Washington; a son, Hugh, of Potomac; two daughters, Lenore J. Latimer of New York City, and Margaret W. Latimer of Brooklyn, N.Y.; a brother, John F., and a sister, Catherine Monroe, both of Washington, and three grandchildren.