Nuyina and Fram: Great ice-breakers, present and past

An Australian ice-breaker built with 21^st century innovation, how does Nuyina compare to the legendary Fram which took Amundsen to Antarctica?

Last November saw the Australian Antarctic Division icebreaker Nuyina start sea trials. One of the most advanced vessels of its kind, it is expected to arrive in its home port of Hobart in mid-2021 to begin Antarctic operations.

Built by the Damen Group at its Romanian shipyard to Polar Class 3 standard from a design developed by Danish naval architects Knud E Hansen, Nuyina forms the centrepiece of the Australian Government’s Antarctic Strategy and 20 Year Action Plan.

The ship will provide a world-class scientific platform for Antarctic researchers, carrying cutting-edge equipment to study the depths of the Southern Ocean, sea ice and the upper atmosphere. It will also be the main lifeline to Australia’s Antarctic and sub-Antarctic research stations for decades to come.

Nuyina can accommodate 117 passengers and 32 crew and up to four helicopters.

Ice-breaking performance

It is an ice-breaker built with 21^st century innovation. Rather than ramming, the bow has been designed to bend and slice through the ice, offering around a 60 per cent increase in ice-breaking performance.

Complex propulsion machinery

Propulsion is by two diesel-hybrid propulsion trains. Each consists of a MAN 16V32/44CR, 9,600kW non-reversible diesel with gearbox, coupling and shaft, driving controllable pitch propellers in diesel direct mode. Each shaft is equipped with a motor/generator that can be connected via a shaft coupling. The generator function is used in transit, supplying power to the vessel’s electrical grid.

A maximum shaft speed will then be combined with minimum propeller pitch. At ship design speed, propellers will run at maximum shaft speed and maximum pitch, however the configuration enables many combinations of thrust and speed in between, controlled by the diesel, propeller and power management systems ensuring an energy-efficient propulsion system.

In silent mode, the main diesels and gearboxes will be de-coupled, with the diesel electric propulsion system operated. The vessel’s electric grid is powered by four, double resilient mounted diesel generators. Electrical power is supplied to the medium voltage switchboards. The main switchboards feed the shaft propulsion motors when connected, or receive power from these units when operated as shaft generators.

Three tunnel thrusters are fitted in the bow as well as the stern skegs to assist the vessel in station keeping in up to sea state 6 and 8 BFT. In dynamic positioning (DP) mode, one switchboard will feed two bow thrusters and one stern thruster, the other feeds two stern thrusters and one bow thruster. The main propellers remain in diesel direct mode with the power take-off online.

Silent mode, when the ship is powered by the electric drive, will help to improve the effectiveness of sensitive acoustic equipment in the ship’s hull and drop keels.

Modern vs history

Nansen's Fram in the ice

Contrast this brand new, state-of-the-art icebreaker with one of the most famous Polar exploration ships in history, the Norwegian Fram. Now a museum ship in Oslo, Fram was a three-masted topsail schooner, designed and built by legendary naval architect Colin Archer at Larvik, Norway, in 1892.

She was ordered by Fridtjof Nansen to be able to travel through the ice fields close to the North Pole. The hull was wide for its length, and shallow, designed to be pushed up on top of the ice when frozen in, rather than crushed. It was constructed of iron and oak with a greenheart timber outer skin.

Apart from the sail rig, a 164kW triple-expansion steam engine was fitted together with a retractable propeller and rudder. The steam engine was replaced with a diesel in 1910, the first Polar exploration ship powered this way.

Fram featured in two of the most important Polar voyages. In 1893, Nansen set off to prove that an ocean current flowed beneath the Arctic ice sheet from east to west. Fram was ‘inserted’ into the ice pack off Siberia to prove the theory – and also that it might pass close to the North Pole. The ship spent nearly three years trapped in the ice, reaching 85° 57° N and emerging from the ice off Spitsbergen.

Arctic spring in south Spitsbergen

In 1910, Fram was then used by Roald Amundsen on his famous voyage to Antarctica.

Fram was retired in 1912 and, following restoration, was later placed in the museum building where it remains today, a fitting tribute to the great explorers who relied on her.

John Barnes is a retired engineer, author and journalist specialising in maritime.