Complex sentence: An hour and one-half later, "Sealion" again closed the convoy and at 0522, launched three torpedoes at a tanker; then swung to fire on "SS Rakuyo Maru", the last ship in the nearer column.
Split into simpler sentences: An hour and a half later, "Sealion" again closed the convoy. At 0522, she launched three torpedoes at a tanker; then swung to fire on "SS Rakuyo Maru", the last ship in the nearer column.