Smoking a pipe and looking out over the vast, icy Arctic, captain Dmitry Lobusov sounds his ship's horn to signal to passengers they are near their destination: the North Pole.

The Arctic Ocean is too deep to drop anchor, but a thick ice embankment offers a dock for Lobusov's giant vessel -- one among Russia's growing fleet of nuclear-powered icebreakers.

The 160-metre (525-foot) ship called "50 Let Pobedy" ("50 Years of Victory") reduces speed.

Passengers, including a gaggle of high school students who won places on the trip in a competition, stepped onto the ice at the North Pole
Passengers, including a gaggle of high school students who won places on the trip in a competition, stepped onto the ice at the North Pole AFP / Ekaterina ANISIMOVA

"Take a left, we'll stop here," Lobusov tells Diana Kidzhi, his second in command and the most senior woman in Russia's nuclear icebreaker fleet.

Thirty minutes later, the giant red-and-black ship is stopped within short walking distance of Earth's most northerly point.

"Well done," Lobusov says, shaking Kidzhi's hand and disembarking from the deck.

Dmitry Lobusov has spent more than half his life aboard giant vessels forging their way through the frozen waters of the Arctic Ocean. Russia is expanding its nuclear icebreaker fleet which Moscow hopes will secure its supremacy over the Arctic as climate
Dmitry Lobusov has spent more than half his life aboard giant vessels forging their way through the frozen waters of the Arctic Ocean. Russia is expanding its nuclear icebreaker fleet which Moscow hopes will secure its supremacy over the Arctic as climate change makes it more navigable. Rosatomflot / Ekaterina ANISIMOVA

The passengers, including a gaggle of high school students who won places on the trip in a competition, step onto the slippery ice to take photos.

The ice they're standing on -- directly above the ocean floor marking the North Pole -- is shifting in Arctic currents, slowly taking them away from the Pole.

"You always find your own North Pole," says Viktor Boyarsky, a 70-year-old Russian explorer returning to the Arctic.

Dmitry Lobusov captains the Russian "50 Years of Victory" nuclear-powered icebreaker
Dmitry Lobusov captains the Russian "50 Years of Victory" nuclear-powered icebreaker AFP / Ekaterina ANISIMOVA

It has taken the icebreaker three and a half days to traverse the 2,400 kilometres (1,500 miles) to the North Pole from Murmansk, the base of Russia's Northern Fleet.

The journey is only possible in summer, when ice cover is at its lowest. Climate change is making the trip gradually easier year by year.

Still, the 95-strong crew is alert for masses of ice that could impede the ship's progress.

The bridge is in constant contact with the crew controlling the ship's nuclear reactor.

Vladimir Yudin, the ship's chief mechanical engineer, is in charge of its 75,000-horsepower engine, the equivalent of about 75 Formula 1 racecars.

"We have 1,144 settings to manage and just as many sensors that need to be checked regularly," Yudin says.

The engine propels forward the ship's body, which is designed to cut through ice. The front is spoon-shaped, Lobusov explains.

"This allows us to get stuck in ice less often and to better penetrate it," says the 57-year-old, who has spent close to half his life in the Arctic.