History of submarines few years before the US, and paralleled subsequent US development in this area. In the 1950s, nuclear power partially replaced diesel-electric propulsion. The sailing of the first nuclear-powered submarine, the USN ""Nautilus"" in 1955 was soon followed by similar British, French and Russian boats. Equipment was also developed to extract oxygen from sea water. These two innovations, together with inertial navigation systems, gave submarines the ability to remain submerged for weeks or months, and enabled previously impossible voyages such as the crossing of the North Pole beneath the Arctic ice cap by the USS "Nautilus" in 1958. Most of the
North Pole North Pole on a motorcycle. On 18 May 1987 USS "Billfish" (SSN 676), USS "Sea Devil" (SSN 664) and HMS "Superb" (S 109) surfaced at the North Pole, the first international surfacing at the North Pole. In 1988 a 13-man strong team (9 Soviets, 4 Canadians) skied across the arctic from Siberia to northern Canada. One of the Canadians, Richard Weber became the first person to reach the Pole from both sides of the Arctic Ocean. On 4 May 1990 Børge Ousland and Erling Kagge became the first explorers ever to reach the North Pole unsupported, after a 58-day ski