the battle were rare, and she only fired 6 six-inch shells from her secondary armament. Erin was the only British battleship not to fire her main guns during the battle. Subsequent activity The Grand Fleet sortied on 18 August to ambush the High Seas Fleet while it advanced into the southern North Sea, but miscommunications and mistakes prevented Jellicoe from intercepting the German fleet before it returned to port. Two light cruisers were sunk by German U-boats during the operation, prompting Jellicoe to decide to not risk the major units of the fleet south of 55° 30' North due to the prevalence of German submarines and mines. The Admiralty concurred and stipulated that the Grand Fleet would not sortie unless the German fleet was attempting an invasion of Britain or that it could be forced into an engagement at a disadvantage. When Stanley was promoted to rear-admiral on 26 April 1917, he was replaced by Captain Walter Ellerton. In April 1918, the High Seas Fleet sortied against British convoys to Norway. Wireless silence was enforced, which prevented Room 40 cryptanalysts from warning the new commander of the Grand Fleet, Admiral Beatty. The British only learned of the operation after an accident aboard the battlecruiser forced her to break radio silence and inform the German commander of her condition. Beatty ordered the Grand Fleet to sea to intercept the Germans, but he was not able to reach the High Seas Fleet before it turned back for Germany. The ship was at Rosyth, Scotland, when the surrendered High Seas Fleet arrived on 21 November and she remained part of the 2nd BS through 1 March 1919. Postwar Captain Herbert Richmond assumed command on 1 January 1919. By 1 May, Erin had been assigned to the 3rd Battle Squadron of the Home Fleet. In October, she was placed in reserve at the Nore but was stationed at Portland Harbour as of 18 November. Richmond was relieved by Captain Percival Hall-Thompson on 1 December. Erin had returned to the Nore by January 1920 and became a gunnery training ship there by February. By June, the ship had become flagship of Rear-Admiral Vivian Bernard, Rear-Admiral, Reserve Fleet, Nore. In July–August 1920, she underwent a refit at Devonport Dockyard. Through 18 December 1920, Erin remained Bernard's flagship and continued to serve as a gunnery training ship. The Royal Navy had originally intended that she should be