A Vietnam War veteran who is critical of the design for a memorial to his fallen comrades failed yesterday to convince the U.S. Fine Arts Commission that it should reject the design and start anew.

Tom Carhart of McLean, a West Point graduate twice wounded in Vietnam, told the commission that the black granite design by Maya Ying Lin, a 21-year-old Yale University architecture student, would be a "shameful degrading ditch -- a black gash of sorrow" in West Potomac Park, near the Lincoln Memorial.

Carhart argued that Lin's design, chosen from 1,420 entries in May by an eight-member jury, chiefly reflected home-front opposition to the war and failed to recognize sacrifices by those who died in the conflict. Carhart told the commission he was one of the strongest initial supporters of the memorial but was affronted by Lin's design for a simple, angled bulkhead largely below ground level.

Commission members listened politely, then reaffirmed the decision they made in July to approve the design in concept. The Lin design, said commission chairman J. Carter Brown Jr., reflects "an extraordinary sense of dignity and nobility . . . precisely because of its simplicity." The commission yesterday approved the selection of granite to be quarried either in Sweden or India, the only places where stone of appropriate quality is said to be located.

Jan C. Scruggs, founder and president of the Vietnam Veterans Memorial Fund, defended the design and attributed Carhart's opposition to "misplaced anger" about the war.