Complex sentence: Originally, torpedo tubes were fitting to both the bow and stern of Submarines, however modern submarine bows are usually occupied by a large sonar array, necessitating torpedoes launched from the sides of the Submarine angled forward.
Split into simpler sentences: Originally, torpedo tubes were fitted to both the bow and stern of submarines. However, modern submarine bows are usually occupied by a large sonar array, necessitating torpedoes launched from tubes angled forward.