British home army in the First World War bridge between Tilbury and Gravesend. There were fears that a German fleet protected by mines and submarines could land a 100,000-strong force before the British Grand Fleet could steam the south from its base at Scapa Flow. To counter this threat, the Admiralty redeployed pre-dreadnought battleships and submarines closer to vulnerable ports, expanded the coastwatch and increased patrolling of the North Sea. In October, Churchill responded to Kitchener's call for the Royal Navy to take more specific precautions against invasion by insisting that the role of the Grand Fleet was to eliminate an invader's covering fleet rather than defeat the
Naval warfare of World War I came under Bulgarian control in 1916 as "Podvodnik No. 18". Russian mines sank one Bulgarian torpedo boat and damaged one more during the war. In the Baltic Sea, Germany and Russia were the main combatants, with a number of British submarines sailing through the Kattegat to assist the Russians. With the German fleet larger and more modern (many High Seas Fleet ships could easily be deployed to the Baltic when the North Sea was quiet), the Russians played a mainly defensive role, at most attacking convoys between Germany and Sweden. A major coup for the Allied forces occurred on August