Dr. Martin Alexander Mason, 74, a retired president of the Capitol Institute of Technology and a former dean of engineering at George Washington University, died Tuesday at Suburban Hospital following a heart attack.

Dr. Mason was an expert in hydraulics and erosion. From 1940 to 1951, he was chief of the engineering and research branch of the beach erosion board of the Army Corps of Engineers. During World War II, his studies of foreign beaches assisted in the planning of amphibious landings, including those on Omaha and Utah beaches in Normandy in the invasion of Europe.

A native of Washington, Dr. Mason graduated from McKinley Technical High School and George Washington University. He earned his doctorate at the University of Grenoble in France.

In 1938, he joined the National Bureau of Standards. He then joined the Corps of Engineers. He was dean of engineering at George Washington from 1951 to 1967. In the 1950s, he also was chairman of the board of the Greater Washington Educational Television Association. He was president of the Capitol Institute of Technology in Kensington from 1967 until he retired in 1971.

Dr. Mason, who lived in Chevy Chase, was a member of the American Society of Civil Engineers, the American Geophysical Union, the American Society of Mechancial Engineers and the Cosmos Club.

Survivors include his wife, Winnifred M. of Chevy Chase; a daughter, Ann Mason of Rockville; a son, Martin E. of Yokohama, Japan, and two grandchildren.

The family suggests that expresssions of sympathy be in the form of contributions to a charity of one's choice.