Francis Howard Townsend Jr., 83, who retired in 1917 after more than 46 years as an engineer with the Washington Suburban Sanitary Commission, died May 11 at Holy Cross Hospital. He had cancer.

Mr. Townsend, who lived in Silver Spring, was materials controls engineer at the time of his retirement. He had been writing a history of the WSSC during his last years. A WSSC spokesman said he had served on the staff longer than any other member of the agency.

Mr. Townsend was born in Baltimore. He earned his engineering degree from Johns Hopkins University there and joined the WSSC in 1920. He sang as a tenor with the D.C. Chapter of the Society for the Preservation and Encouragement of Barber Shop Quartet Singing in America, of which he was a part-time director, and with the Singing Capital group.

He was director of the church choir of the Georgia Avenue Christian Church in Wheaton for 35 years before retiring eight years ago. He sang on occasion with the Takoma Park Presbyterian Church.

He is survived by his wife, Lillian S., and a son, H. Gordon Townsend, of Silver Spring, two sisters, Olive Warfield and Mildred Jones, both of Baltimore, and four grandchildren. A daughter, Barbara Kozachenko, preceded him in death.

The family suggests that expressions of sympathy be in the form of contributions to the Georgia Avenue Christian Church and Encouragement of Barber Shop Quartet Singing in America, 4912 Butternut Dr., Rockville, Md. 20853.