sentences:  Together with her sister "Taiyō" and the heavy cruiser , and escorted by six destroyers, "Chūyō" departed Yokosuka on 4 April and made a brief stopover at the island of Saipan three days later.On 9 April, the carrier was attacked by the submarine , but the detonators for the Mark 14 torpedoes were defective, causing them either to detonate early or not to detonate at all, denting "Chūyō"s hull.The ship made four more trips between April and August, accompanied by her sister ship each time, before she was given a brief refit between 9 and 18 August.