2uNDON, July 7p (INS)—a Russia-bound convoy of British and], Soviet merchant ships reached port safely and discharged their cargoes; despite the heaviest and longest sustained air attack in the history of warfare, the Daily Mail de clared today. At least 2500 planes were over the convoy in 230 attacks » the Daily Mail account said. When the ships docked the Germans continued to attack, averaging it raids daily. “For determination, sustained ferocity and prodigal sacrifice the six-day attack has never been equalled,” said the Daily Mail. The attacks began when the con voy rounded the northern coast of Norway and continued incessantly. There were raids every few min utes. During the final 600 miles of the voyage the skippers of the freighters were constantly on their bridges, engineers never left their engine rooms, and the deck gunners matched — brief periods of sleep at their gun stations. Thirty attacking planes were shot down on the first day and many others damaged. There was no estimate of total losses by the enemy, but they were assumed to have been very large in view of the fact that the convoy got through. One gunner was quoted as saying: “We held our fire until the l anes were close overhead and then let them have it in the belly. It was a wonderful SIX] days. The enemy planes shadowed the convoy constantly, appar ently directing the bombers from their shore bases in Nor way, Finland and the occupied area of North Russia. But throughout the sun-day bat te the anti-aircraft fire from the convoy and escort ships evened up the odds despite the weight and fury of the German attacks. As the convoy neared the Rus sian port Red army fighter planes joined the battle, and aided des troyers In the destruction of two enemy submarines. . One Russian freighter was set latire by direct bomb hits and the crew, Including six women, fought the flames for twelve hours be fore the blaze was nully doused.