Russia’s new flagship icebreaker, billed as the world’s largest and most powerful, left St Petersburg’s Baltic Shipyard this week, bound for Murmansk, dogged by lawsuits stemming from its late delivery and sailing on only two of its three propellers.

Still, the massive ship represents a milestone in President Vladimir Putin’s ambitions for dominance within the Arctic region – a plan that relies on keeping the polar region open for shipping on a year-round basis.

The Arktika, as the vessel is called, will now head to Atomflot, the headquarters of the Russian nuclear icebreaker fleet, three years behind schedule thanks to supply chain delays and technical snafus with one of its three electrical engines.

During its two-week journey to Murmansk, the vessel will undergo preliminary ice breaking tests near Franz Josef’s Land, an Arctic Ocean archipelago to Murmansk’s north, said Rosatom, Russia’s state nuclear corporation, in a statement.

As the lead ship in Russia’s new LK-60 icebreaker line, the Arktika is 173 meters long and stands as tall as a 15-storey building. Its twin RITM-200 reactors deliver a combined 175 megawatts of power, propelling it through ice as thick as three meters, making it the most powerful civilian vessel in the world.

But the vessel will be operating at a reduced capacity owing to an engine difficulty that has not yet been repaired.

During the Arktika’s February sea trials, a short circuit brought down one of the vessel’s starboard-side electrical propulsion motors. While the motor has nothing to do with the Arktika’s nuclear reactors, the 300-ton system has yet to be replaced, and its absence reduces the ship’s power to 52 megawatts – far less than its advertised power. That will make it difficult to draw accurate conclusions on the Arktika’s ice breaking abilities when it passes though Franz Josef’s Land.

The lacking motor also impacts the Arktika’s maneuverability. Eventually, the vessel will have to return to the Baltic Shipyard for full repairs. Russian media have suggested that might not happen until at least 2021.

A new series of upgraded nuclear icebreakers are central component of a Kremlin strategy to keep Arctic sea routes open on a year-round basis. Russia has since Soviet times maintained the world’s largest stable of these vessels. But many have been decommissioned in recent years, and Moscow has embarked on renewing the fleet.

The backbone of this effort is the Northern Sea Route, a 5,600-kilometer sea artery joining Europe to Asia, whose frozen shores are laden with fossil fuels and mineral deposits..

The hulls of the Arktika’s sister vessels, the Ural and the Sibir, have also been floated by the Baltic Shipyard. Two more vessels in the line are scheduled to launch in 2024 and 2026, according to a $1.47 billion government tender published last summer.

The passage lops days off conventional shipping arteries like the Suez Canal. But icebreaking vessels are still needed to keep trade lanes open for cargo convoys for much of the year – a service for which Moscow charges shippers a hefty toll.

Atomflot has filed its suits against the Baltic Shipyard in Moscow’s Arbitration court, the Barents Observer reports. In turn, the shipyard is suing one of its own suppliers – the giant Kirov Plant in St Petersburg, which manufactures heavy machinery.