Bairdmaritime provides a review of Australia’s new icebreaking research and supply vessel.

Looking for more information, I found a very extensive description here (click on the menu tab on the upper right). This is a big, powerful, very versitile ship, but I wonder about the choice of propulsion and hope our resident icebreaker expert, Tups, will comment.

First, at 25,500 tons, it is much larger than either Healy (16,000) or Polar Star (13,623 tons). It is way longer as well at 160.3 m (526 ft), compared to Healy (420 ft / 128 meters) and Polar Star (399 ft / 122 meters). She is even larger than the Polar Security Cutter PSC (22,900 tons and 460 ft / 140 meters in length).

A good part of the ship’s size is due to the fact that this ship is more than an icebreaker. While a typical US support mission to Antarctic would envolve three ships, an icebreaker, a supply ship, and a tanker, this ship is a combined icebreaker, dry cargo ship, tanker, and research vessel. The crew is small, 32, but there are accommodations for an additional 117 expeditioners plus 1200 tonnes of cargo and 1.9 million litres of fuel.

Aviation facilities are generous. The hangar can accommodate four small AS350 B3 helicopters or two Sikorsky S-92 that are larger than the H-60s.

It has a large number of boats including a pair of barges. Each barge has two 448 kilowatt (600 horsepower) engines and a water jet propulsion system that provides greater manoeuvrability than propellers. The barges carry general cargo from ship to shore in Antarctica.

On the cargo hatch covers near the bow of RSV Nuyina are two 16.3 metre-long, 6.2 metre-wide barges, each capable of carrying more than 45 tonnes of cargo.

The aluminium barges can operate in calm seas and up to 50 knots of wind, at a speed of eight knots.

Propulsion: 

What I found most surprising was the choice of propulsion systems. This is a seriously powerful icebreaker, but unlike most modern icebreakers, it does not use steerable podded diesel electric systems (such as Azipods). Instead all power goes through two shafts to controlable pitch propellers. Both the sources reported power comes from two V16 diesel engines (19,200 kW each) geared diesels and 4 diesel generators (7,400 kW each) powered by diesel generators. From the https://www.antarctica.gov.au/ site which Bairdmaritime seems to have copied.

RSV Nuyina can cruise efficiently in open water, operate silently (in ‘Silent R’ mode) during scientific operations, or continuously break ice up to 1.65 metres thick.

RSV Nuyina has a diesel-electric propulsion system that provides different levels of power depending on the task.

In icebreaking mode RSV Nuyina uses its full propulsion system – two V16 diesel engines (19,200 kW each), and 4 electric motors (7,400 kW each) powered by diesel generators.

In its 12–14 knot cruising mode, the ship relies on the electric motors.

There are two engine rooms to provide an enhanced level of safety and redundancy. Each room houses a V16 diesel engine and two diesel generators.

That seemed like an awful lot of power for the modest maximum and cruising speed reported. The descrtiption sounded like a total of 68,000 KW total (about 92,000 HP) but that seemed unlikely.

Wikipedia indicates they max total power is a still very respectable 26,600 KW or 35,657 HP (confirmed here). This would make her slightly more powerful than Healy (2 × 11.2 MW (15,000 hp).

Something did not sound right.

Looking up the MAN 16V32/44CR engines reportely installed I found that they were rated at 9600 KW not 19,200 each, rather that would be the total for the two. Given a total output in the icebreaking mode, of 26,600 KW, 19,200 of which comes from the two main diesels, that means the electric motors would provide an additional 7400 KW total, or probably 3700 KW each which be enough for a 12 knot cruise. That makes sense.