boiler explosion on 16 August 1906, the result of a loss of feedwater that caused the boiler to overheat. She entered Chatham Dockyard in the United Kingdom in 1908 for another refit. During this refit, her 12-pounder guns were relocated from the main deck to the superstructure, and the four forward gun ports were plated over to reduce flooding in heavy seas. When her Chatham refit ended in February 1909, Implacable transferred to the Channel Fleet, then to the Atlantic Fleet on 15 May 1909. Following a fleet reorganisation on 1 May 1912, Implacable transferred to the 5th Battle Squadron in the Second Home Fleet at the Nore on 13 May 1912. World War I When World War I began in August 1914, the 5th Battle Squadron was assigned to the Channel Fleet and based at Portland. Implacable and her half-sister were attached temporarily to the Dover Patrol in late October 1914 to bombard German Army forces along the coast of Belgium in support of Allied forces fighting at the front. The German forces were attacking French positions to the east of Dunkirk, and they were in dire need of heavy artillery support. A flotilla of destroyers and monitors helped to break up the attack before Implacable and Queen arrived, but reports of an imminent German counterattack with armoured cruisers, which ultimately failed to materialize, led the British to send the battleships to guard against it in company with the Harwich Force. When it had become clear that the German fleet posed no threat, they returned to the Channel Fleet. On 14 November 1914, the 5th Battle Squadron was transferred to Sheerness in case of a possible German invasion attempt, but it returned to Portland on 30 December 1914. In January 1915, the British and French navies began to draw ships to the eastern Mediterranean to begin operations against the Ottoman Empire, including several ships from the 5th Battle Squadron. By the end of the month, only Implacable, Queen, and their sisters and , along with the light cruisers and that had been assigned to support the 5th Squadron, were still at Portland. Dardanelles campaign In March 1915, as the British and French fleets waging the Dardanelles campaign were preparing to launch a major attack on 18 March, the overall commander, Admiral Sackville Carden, requested two more battleships of the 5th Squadron, Implacable and Queen, to be transferred to his