PD-50 (Russian: ПД-50), Soviet designation Project 7454, was a Russian large floating dry dock built at the Götaverken Arendal shipyard in Gothenburg, Sweden and commissioned in the 1980s. At the time, it was the world's largest floating dry dock and used primarily to service the ships and submarines of the Northern Fleet. The 330-metre (1,082 ft 8 in) long and 79-metre (259 ft 2 in) wide floating dock was owned by and stationed at Roslyakovo, near Murmansk. In November 2018, the dock sank after a power outage while holding the aircraft carrier/aircraft cruiser Admiral Kuznetsov.