 The attack by 131 1 Group aircraft, 113 Lancasters, 6 Pathfinder Shifters and 12 Pathfinder Backers-Up began at to destroy the V2 works, in two buildings about long.The bombers carried a minimum of ninety and just under seven hundred bombs.The pathfinders had to move the marking from the first wave targets to the new ones, which had never been tried before.