Barney Ewell, who was one of the world's top-ranked sprinters during and after World War II and who won three medals at the age of 30 when the Olympics were revived in 1948, died yesterday in Lancaster General Hospital in Pennsylvania. He was 78 years old.

A son, Barney Ewell Jr., said that Ewell had died from complications following amputations on both legs.

Norwood H. (Barney) Ewell was born on Feb. 25, 1918, in Lancaster and went on to Penn State University, where he immediately became renowned as a sprinter. He won 12 gold medals and championships in three straight years in the IC4A collegiate meets starting in 1940, and he won 11 gold medals in Amateur Athletic Union national meets. He also set American and world records at 50 yards, 60 yards and 100 meters.

But Ewell was denied the opportunity to compete in the Olympics because World War II wiped out the Games in 1940 and 1944. By then, he was serving in the United States Army, still sprinting but facing the loss of his prime years.

After the war, Ewell returned to Penn State and completed his education in 1946, and then qualified for the Olympics in 1948 by equaling the 100-meter world record of 10.2 seconds in the final United States Olympic trials while also qualifying in the 200-meter dash.

Ewell was 30 years old and considered well past his prime for a sprinter. But in three stunning performances in London, Ewell won two silver medals and one gold medal and came within a blink of sweeping three golds.

In the 100-meter dash final, he raced to an apparent dead heat with Harrison Dillard. Dillard, who had failed to qualify for the United States team in his specialty, the high hurdles, made the team as a sprinter and flashed 100 meters in 10.3 seconds with Ewell four lanes to his left. Believing he had won the race as he crossed the finish, Ewell danced with his hands over his head. But when it was determined that Dillard had actually crossed first, Ewell, who was timed in 10.4 seconds, accepted the decision with grace.

Curt Stone, the distance runner who was Ewell's classmate at Penn State and who performed in three Olympics, remembered the drama of the race yesterday. "Barney raised his hands up in victory," Stone said, "but they quickly determined that Dillard had won by a whisker. But Barney was all class. He promptly turned, went over to Dillard and congratulated him warmly."

In the 200-meter dash, Ewell again missed by a tick, this time to Mel Patton. But the ultimate suspense was yet to come: In the 400-meter relay, Ewell ran the first leg on a team of exceptional talent, followed by Lorenzo Wright, Dillard and Patton. The American team won handily but was disqualified when an official ruled that Ewell had passed the baton to Wright outside the passing zone.

The gold medal was awarded to Britain but, three days later, a jury of appeal viewed films of the race and reversed the finding.

In his later years, Ewell lived in Lancaster as a hero. But his health was undermined by two operations for partial amputations on both legs.

He is survived by his wife, Duella; three sons, Barney Jr., Patrick and Maurice; a daughter, Denise, and two grandchildren.

Henry N Ewell