Ernest Rivers Welch 73, a professor emeritus and former associate dean of the school of engineering at Howard University, died Thursday at the Wisconsin Avenue Nursing Home. He had suffered from cancer.

In addition to his academic career, which lasted 47 years, Col. Welch was an officer in the Army reserves from his graduation from Howard in 1926 until his retirement from the military in 1964. He commanded a battalion of engineers in the Phillippines during World War II.

Col. Welch was born in Tuskegee, Ala., and attended schools there. His family moved to Washington while he was growing up and he graduated from Dunbar High School. He then went on to Howard.

He joined the Howard faculty as an instructor in electrical engineering following his graduation. He earned a master's degree in electrical engineering at the University of Michigan while still maintaining his ties with Howard. He was on military leave from the university during World War II.

In 1966, he was named associate dean of the Howard school of engineering and architecture. When engineering and architecture. When engineering and archietecture became separate schools in 1970, he became acting dean of the school of engineering. Form 1971 until his retirement in 1973, he was associate dean of engineering.

Col. Welch was a registered engineer in the District of Columbia and Maryland. He was a senior life member of the Institute of Electrical and Electronic Engineers. He also was a life member of the American Association for the Advancement of Science, a member of the American Society for Engineering Education, the National Technical Association, and the National Society of Professional Engineers. He was a member of the Bethea-Welch Post 7284 of the Veterans of Foreign Wars and had been active in the Boy Scouts of America.

Survivors include his wife, Margaret Petway Welch, of the home in Washington; his mother, Mamie R. Welch, of Tuskegee; two sisters, Wilhelmina W. Burrell, of Asbury Park, N.J., and Margaret W. Wilson, of Kings Mountain, N.C., and a brother, John A. Welch, also of Tuskegee.

The family suggests that expressions of sympathy be in the form of contributions to the American Cancer Society.