almost any warship and equipped with ASW apparatus, became commonplace during the 1960s. Increasingly capable fixed-wing maritime patrol aircraft were also widely used, capable of covering vast areas of ocean. The Magnetic Anomaly Detector (MAD), diesel exhaust sniffers, sonobuoys and other electronic warfare technologies also became a staple of ASW efforts. Dedicated attack submarines, purpose-built to track down and destroy other submarines, became a key component as well. Torpedo carrying missiles, such as ASROC and Ikara, were another area of advancement. History Origins The first attacks on a ship by an underwater vehicle are generally believed to have been during the American Revolutionary War, using what would now be called a naval mine but what was then referred to a torpedo. Even so, various attempts to produce submarines had been made prior to this. In 1866, British engineer Robert Whitehead invented the first effective self-propelled torpedo, the eponymous Whitehead torpedo; French and German inventions followed soon thereafter. The first submarine with a torpedo was Nordenfelt I built in 1884–1885, though it had been proposed earlier. By the outbreak of the Russo-Japanese War, all the large navies except the Germans had acquired submarines. Nevertheless, by 1904, all powers still defined the submarine as an experimental vessel and did not put it into operational use. There were no means to detect submerged U-boats, and attacks on them were limited at first to efforts to damage their periscopes with hammers. The Royal Navy torpedo establishment, HMS Vernon, studied explosive grapnel sweeps; these sank four or five U-boats in the First World War. A similar approach featured a string of charges on a floating cable, fired electrically; an unimpressed Baron Mountevans considered any U-boat sunk by it deserved to be. Another primitive technique of attacking submarines was the dropping of hand-thrown guncotton bombs. The Lance Bomb was developed, also; this featured a cone-shaped steel drum on a shaft, intended to be thrown at a submarine. Firing Lyddite shells, or using trench mortars, was tried. Use of nets to ensnare U-boats was also examined, as was a destroyer, , fitted with a spar torpedo. To attack at set depths, aircraft bombs were attached to lanyards which would trigger their charges; a similar idea was a guncotton charge in a lanyarded can; two of these lashed together became known as the Depth Charge Type A. Problems with the lanyards tangling and failing to function led to