Timothy J. Quinlan, 57, a partner in the architectural firm of Wilmot, Bower, Quinlan and Associates in Silver Spring, died of an aortic aneurysm Tuesday at Washington Hospital Center.

He became a partner in the firm in 1970. Since then he had worked as project architect for the design and installation of medical facilities, such as intensive-care units, at Washington Hospital Center, Capitol Hill Hospital, and Providence Hospital in Washington.

He had worked previously for Edward H. Noakes Associates where he was a designer of medical and health care facilities. He was with Noakes for nine years.

Mr. Quinlan had lectured at George Washington University since 1972, where he taught a course for hospital administrators in hospital design.

He was a native of Waterbury, Conn. He attended the U.S. Merchant Marine Academy and earned a bachelor's degree in architecture at Catholic University.

Mr. Quinalan served as a Navy officer in the Pacific during World War II.

His professional memberships included the American Hospital Association and the Construction Specification Institute. He was a corporate member of the American Institute of Architects.

Survivors include his wife, Marie R., and a son, Patrick, both of the home in Severna Park, Md.; two other sons, Timothy Jr., of Baltimore, and Michael, of Crofton, Md.; two daughters, Maureen D'Aiutolo, of Baltimore and Kathleen Sheridan, of College Park; two sisters, Peggy Kalisuch, of California, and Marion Libano, of Connecticut, and one grandchild.

The family suggests that expressions of sympathy be in the form of contributions to either the American Heart Association or the Wheaton Rescue Squad.