The diesel engine and the electric battery remained the power source for submarines until nuclear power was introduced in the 1950’s. While many modern submarines are still diesel powered, nuclear power has become the propulsion system of choice in US submarine construction. The British Royal Navy's submarine force is also entirely nuclear-powered. The French, Russian, and Chinese Navies use nuclear propulsion for some of their submarines.
World War IThe United States entered World War I in 1917 with a total of 24 diesel powered submarines. U.S. Navy subs patrolled the waters off the U.S. East Coast and deployed overseas to the Azores and Ireland. The American submarines primary missions were to escort Allied shipping and counter the German U-boat threat.
Though there were no confirmed sinkings of U-boats by American submarines the number of German attacks repulsed by near misses showed the submarine to be an effective anti-submarine weapon. However, it was Germany's use of the U-boat in World War I that demonstrated the vital role the submarine would play in the next global conflict.
Naval Shipyards & All-Welded SubmarinesAfter the war, the U.S. Navy slowly built up its sub force. Construction contracts with commercial shipyards were cut back, forcing the Lake Torpedo Boat Company to go out of business in 1922. The Portsmouth Naval Shipyard in New Hampshire became one of the largest submarine builders in the U.S. and between 1924 and 1929 the Portsmouth yard designed and built five 381-foot V-class submarines. Between 1932 and 1941, Portsmouth built an additional 22 submarines in the 1500-ton category.
It was during this period that the first all-welded submarine, USS Pike (SS-173), was completed. The welded hull allowed Pike to submerge to much greater depths than her predecessors and at the same time provided greater protection against depth-charge attacks.
SonarSonar is a system for detecting submarine sound in the water. It was first developed by the British for use against U-boats in World War I. Radar uses radio waves to detect objects on and above the land and sea surface. Radar was developed in the 1930s to detect aircraft.