U-47 entered through gaps left by aging First World War blockships, some of which had been moved for peacetime exercises and not replaced. The submarine's first torpedo spread missed its target. Because no one detected the attack or began a pursuit, U-47 could reposition and fire again. The second strike sank Royal Oak with heavy loss of life. The sequence makes the failure systemic: decayed obstacles were compounded by missing detection and response.
Notable Point · 41:48-43:02
Why U-47 was able to attack Royal Oak twice
U-47's first torpedoes missed, but the absence of detection or pursuit allowed a second attack that sank Royal Oak.