The British and American navies, soon followed by France, Portugal and the Scandinavian countries, had adopted the German Schnorchel which the English made the "Snort" and the Americans, the "Snorkel". Not only does the process allow the batteries to be recharged in almost complete immersion but, in operations, the submarine can use its diesel, keeping its batteries charged until the moment when a quieter approach is necessary in the vicinity of the objective. .
In the United States, a large number of submarines built during the war underwent what was called a “Guppy” transformation. Their superstructures were razed to reduce their resistance to water and, at the same time, reduce their noise under water.
The hulls were also reinforced to double the capacity of the batteries. Similar transformations were also undertaken in the British navy and the other European navies. to be very excited — perhaps because a lot of the technology, the engineering planners along with a lot of half-finished submarines fell into their hands in 1945. However, there is no evidence that it Only one Walther submarine remains in service with the Soviet Navy today.
By the late 1950s, the British Navy had reverted to diesel-electric engines, although some claimed that they were the quietest in the world in diving.
In America, the hydrodynamics of shapes such as those of the whale or the dolphin have been studied extensively. This resulted in the teardrop hull of the experimental Albacore submarine completed in 1953.
It remained the basic design for American and English nuclear submarines. One of the characteristics of these shapes relates to the behavior of the submarine when diving. Instead of leaning outward under the effect of the bar, it “turns on the wing” like an airplane. Another remarkable point, even with diesel-electric propulsion, the Albacore had a considerably increased speed of 33 knots while diving compared to 14 or 16 for the last conventional submarines built for the US Navy in the 1950s.