During the battle of the Denmark Strait against the German battleship "Bismarck", the main battery of the newly commissioned had mechanical problems: it started to fire three-round salvos instead of five-round salvoes, and there were problems in all except for the twin "B" turret. The main battery output was reduced to 74 percent ("Bismarck" and "Prinz Eugen" achieved 89% and 85% output, respectively) during the engagement, as out of seventy-four rounds ordered fired, only fifty-five were possible. 'A' turret was taking in water leading to discomfort for its crew and "Y" turret jammed at salvo 20. The number of known defects in the main armament that was hampering 14-inch fire, the damage sustained and the worsening tactical situation forced Captain Leach to disengage from combat. With the range down to 14,500 yards and with five of his 14-inch guns out of action, Leach decided to break off his engagement with a superior enemy. Stephen Roskill in the "War at Sea" (the official British history of the Second World War at sea), Volume 1, describes the decision to turn away: "In addition to the defective gun in her forward turret another 4 gun turret was temporarily incapacitated by mechanical breakdowns. In these circumstances Leach decided to break off the action and, at 0613, turned away under cover of smoke." During the later action with "Bismarck", was also having trouble with her main battery, and by 0927 every gun missed at least one salvo due to failures in the safety interlocks for antiflash protection. John Roberts wrote of main gunnery problems encountered by "King George V":