John Francis "Spike" Sargent, 79, a marine engineer who retired from the Department of the Army in 1982, died of pneumonia Dec. 28 at the Mount Vernon Nursing Center in Alexandria.

Mr. Sargent, who lived in Alexandria, was born at Fort Benjamin Harrison, Ind., and attended the University of Virginia and Virginia Tech. He graduated from the Newport News Shipbuilding and Dry Dock Apprentice School.

He served on active duty with the Army during World War II and again during the Korean War. Later, he was a member of the Army Reserve until retiring as a colonel about 1990.

He began his career as a civilian engineer for the Department of the Army in 1945 in Newport News. Thirty-three years ago, he was transferred to this area.

His work included the design and development of amphibious vehicles for ship-to-shore operations.

His final assignment before retiring was as project manager and chief design engineer for the Army's LACV-30, a 30-ton cargo air cushion vehicle.

He was president of the Fort Belvoir chapter of the Reserve Officers Association and chief usher at Good Shepherd Catholic Church.

Survivors include his wife, Dorothy Lambert Sargent of Alexandria; three children, Linda Sargent Kaufman of Roanoke, LaDonna Sargent Johnson of Greenwood, S.C., and John Francis Sargent of Washington; 10 grandchildren and one great-grandchild. A daughter, Dr. Brenda Lee Sargent, died in 1991.