The floating dock administering repairs to Russia's only aircraft carrier isn't floating anymore

At the 82nd Ship Repair Yard in Murmansk, floating dock PD-50 — one of the largest floating docks in the world — sank. The accident occurred before dawn on October 30, as the “Admiral Kuznetsov” Russian aircraft carrier was exiting the dock. According to the news agency SeverPost, two tower cranes collapsed during the incident, one falling onto the ship.

Four people were injured in the accident, and one person is still unaccounted for. Many repair workers at the dock fell into the water, when the dock sank, according to the website Murmansky Vestnik. The injured workers were hospitalized with hypothermia, according to TASS, and one of the men reportedly sustained abdominal trauma. Two of the victims were later transferred to intensive care, and the other two were soon discharged. A fifth dock worker is still missing, according to Murmansk Governor Marina Kovtun. Regional officials say the missing man is a senior shift mechanic, but they haven’t yet released his name. Roughly 70 people fled when the dock was evacuated.

A sudden electric outage caused the accident. After a power surge, the water pumps shut down, causing the tanks to flood quickly, which plunged the dock into the water, according to the “Zvezdochka” Ship Repair Center. On October 29, Murmansk experienced electrical supply interruptions when snow and ice damaged power lines.

The Admiral Kuznetsov sustained damage, as well. The United Shipbuilding Corporation reported that the tower crane that fell on the aircraft carrier’s flight deck damaged part of the hull, but didn’t hurt any “vital” equipment. At the time of this writing, the crane was still crashed on the ship. According to “Zvezdochka,” the damages shouldn’t affect the Admiral Kuznetsov’s repair schedule. The United Shipbuilding Corporation later explained that the crane opened a hole in the ship's hull as big as 5 meters (16 feet), but the damage will be cheap to repair and should take no longer than a week and a half. “This is standard work for our welders,” the head of the corporation told RIA Novosti.

The ship's repairs will supposedly remain on schedule. After the accident, the ship was towed to the 35th Ship Repair Yard in Murmansk, where officials reiterated that repairs would stay on schedule. Experts told the newspaper Novaya Gazeta, however, that floating dock PD-50 was the only dock in Russia capable of making the necessary repairs and upgrades to the aircraft carrier. But there’s some disagreement about this issue, as another source told the news agency Interfax that Novorossiysk’s floating dock PD-190 is also up to the job.

In December 2011, there was a fire aboard a nuclear submarine at the 82nd Ship Repair Yard in Murmansk. Docked at PD-50, the K-84 Yekaterinburg nuclear-powered ballistic missile submarine caught fire in dry-dock, while loaded with nuclear-warhead-tipped missiles, torpedoes, and two nuclear reactors. The floating dock was intentionally flooded twice to put out the flames, which burned for more than 24 hours.