First nuclear submarine
Who
USS Nautilus
What
first
Where
United States (Groton)
When
The world's first nuclear-powered submarine was USS Nautilus, launched at Groton, Connecticut, USA, on 21 January 1954. Built by General Dynamics Electric Boat, Nautilus was 98.7 m (324 ft) long, with a beam of 26.8 m (88 ft). She had a crew of 95 enlisted men and 10 officers, and was capable of reaching speeds of over 20 knots (37 km/h or 23 mph). Steam provided by nuclear-generated heat turned two turbines, developing 11,200 kW (15,000 hp). In 1986 she was put on display at the Submarine Force Museum at Groton, Connecticut, where she remains today.

USS Nautilus SSN 571 was the first nuclear powered submarine to enter service and marked a revolution in naval warfare, since it could remain submerged for much longer than conventional submarines and travel further. It made an early record breaking voyage of 2,222 km (1,381 miles) in 90 hours in 1955 and was the first submarine to travel under the ice cap to the North Pole arriving there at 11.15 am on 3 August 1958.