Submarine Technology Through the Years 2

	Another consideration in the early 1920s was the use of a submarine to forward deploy aircraft. Submarine S-1 was the first U.S. submarine fitted out and extensively tested with a small scout plane. (Hi-Res)
	The Cuttlefish was basically an Americanized U-boat. This design incorporated the first complete double hull in a U.S. submarine and had an 11,000 nm range at 19 kts. (Hi-Res)
	The S-class boats were used as the test platforms for a range of sonar designs tested in the 1920s and 1930s. Higher frequencies and small, trainable transducers allowed for narrow beam width and exclusion of natural sea noises and other interference. (Hi-Res)
	The Porpoise (SS-172) class was the first all-electric drive submarine, and the precursor to the World War II fleet submarines. With its new diesel engine, this design had a maximum surface speed of 19 kts. Auxiliary diesels avoided the need to drain the battery while operating surfaced. This reduced battery charging cycles from 150/year to 30/year, greatly extending battery life. (Hi-Res)
	Gato (SS 212) provided the prototype design for the World War II vintage submarine. Construction of this class was accelerated in 1940 due to the escalation of the war in Europe. In order to increase production capability the Manitowoc Shipbuilding Company in Wisconsin was contracted to build submarines under license from Electric Boat. (Hi-Res)
	The advent of the submarine bathothermograph (SBT) in 1942 provided the submarine force with an important tool for covert patrol operations and attacks. Herring (SS-233), pictured, was an early example of the successful application of the SBT. (Hi-Res)
	Within two years of the end of the war, the U.S. Navy had a functional snorkel mast on an operational, high speed submarine- the Irex (SS 482). (Hi-Res)
	The Tang was the first submarine designed for underwater performance rather than surfaced speed and handling. Key features included removing the deck guns, streamlining the outer hull, replacing the conning tower with a sail, installing new propellers designed for submerged operations, installing more air conditioning and a snorkel mast, and doubling the battery capacity. (Hi-Res)
	In 1951 the submarine force achieved another important milestone. Guavina (SS 362) used an experimental searchlight sonar to distinguish the sound signature of Seacat (SS 399) and the fleet tug Salinian (ATF 161) at ranges of 9-10 nm. (Hi-Res)
	The experimental submarine Albacore (AGSS-569) introduced the distinctive teardrop shape hull, which has influenced all follow-on submarine designs. This design provided for major advances in noise reduction, underwater speed and the use of low carbon (HY-80) as a structural steel. It also tested the first fiberglass sonar dome, installed in 1953. (Hi-Res)
	The first warships built with a teardrop shape hull were the Barbel (SS 580) class. This class was also the first to incorporate a centralized arrangement of ship controls and combat operations, or "attack center". (Hi-Res)
	The USS Nautilus, pictured, represented a watershed for the U.S. Navy’s submarine program. This was the world’s first nuclear-powered submarine, a design improvement which allowed for a dramatic increase in range and operational flexibility. The Nautilus is also credited with forcing the shipbuilders to develop an improved quality control program. (Hi-Res)
	The USS Seawolf was the first and only U.S. submarine built with a liquid metal nuclear reactor. The liquid metal (sodium) provided a more efficient power plant, but posed several safety hazards for the ship and crew. (Hi-Res)