Allan Rockwell McCann was in charge of the development of a submarine rescue chamber, which bears his name, "The McCann Submarine Rescue Chamber". Additionally he was assigned as Liaison Officer / Engineer when the submarine was converted for use in the under ice attempt to circumnavigate the Arctic Ice cap and voyage to the North Pole. Modifications to the submarine were extensive, and contained innovations of a telescoping conning tower, an ice drill, an incorporated diving bell and an Air Lock, designed by Simon Lake. The submarine was designated "Nautilus" and leased for one dollar to Lake and Danenhower, Inc., of Bridgeport, Connecticut,
Submarine Soviet Union () as part of the Cold War nuclear deterrent strategy. During the Cold War, the US and the Soviet Union maintained large submarine fleets that engaged in cat-and-mouse games. The Soviet Union lost at least four submarines during this period: was lost in 1968 (a part of which the CIA retrieved from the ocean floor with the Howard Hughes-designed ship "Glomar Explorer"), in 1970, in 1986, and in 1989 (which held a depth record among military submarines—). Many other Soviet subs, such as (the first Soviet nuclear submarine, and the first Soviet sub to reach the North Pole)