with the creation of the tank and mechanised warfare. The British first tanks were used during the Battle of the Somme on 15 September 1916. Mechanical reliability was an issue, but the experiment proved its worth. Within a year, the British were fielding tanks by the hundreds, and they showed their potential during the Battle of Cambrai in November 1917, by breaking the Hindenburg Line, while combined arms teams captured 8,000 enemy soldiers and 100 guns. Meanwhile, the French introduced the first tanks with a rotating turret, the Renault FT, which became a decisive tool of the victory. The conflict also saw the introduction of light automatic weapons and submachine guns, such as the Lewis gun, the M1918 Browning Automatic Rifle, and the MP 18. Another new weapon, the flamethrower, was first used by the German army and later adopted by other forces. Although not of high tactical value, the flamethrower was a powerful, demoralising weapon that caused terror on the battlefield. Trench railways evolved to supply the enormous quantities of food, water, and ammunition required to support large numbers of soldiers in areas where conventional transportation systems had been destroyed. Internal combustion engines and improved traction systems for automobiles and trucks/lorries eventually rendered trench railways obsolete. Naval Germany deployed U-boats (submarines) after the war began. Alternating between restricted and unrestricted submarine warfare in the Atlantic, the Imperial German Navy employed them to deprive the British Isles of vital supplies. The deaths of British merchant sailors and the seeming invulnerability of U-boats led to the development of depth charges (1916), hydrophones (sonar, 1917), blimps, hunter-killer submarines (HMS R-1, 1917), forward-throwing anti-submarine weapons, and dipping hydrophones (the latter two both abandoned in 1918). To extend their operations, the Germans proposed supply submarines (1916). Most of these would be forgotten in the interwar period until World WarII revived the need. Aviation Fixed-wing aircraft were first used militarily by the Italians in Libya on 23 October 1911 during the Italo-Turkish War for reconnaissance, soon followed by the dropping of grenades and aerial photography the next year. By 1914, their military utility was obvious. They were initially used for reconnaissance and ground attack. To shoot down enemy planes, anti-aircraft guns and fighter aircraft were developed. Strategic bombers were created, principally by the Germans and British, though the former used Zeppelins as well. Towards the end of the conflict, aircraft carriers were used for the