As befits a vessel of the size, strength, purpose and capacity of the Nuyina, a series of smaller support craft — a science tender, two personnel transfer tenders, a stern tender and two barges — will form part of the ‘ship system’.
Australian Antarctic Division Icebreaker Project Officer Justin Hallock said the system approach means that the Nuyina has dedicated facilities to accommodate the smaller support vessels. These include dedicated stowage positions, tailored lifting and securing equipment, power outlets to charge batteries and warm engines, and facilities for refuelling. The tenders will also be the same colour as the mother ship.
“Because the tenders and barges are part of the ship’s system they will go through the same testing regime as Nuyina,” Mr Hallock said.
The two aluminium personnel transfer tenders will be operated by two crew and will transfer up to eight expeditioners and 150 kilograms of baggage from the ship to Antarctic stations. They will be deployed by “certified man-riding davits” (small cranes) over the side of the ship, with people and cargo already loaded.
“The tenders are made to a very robust design by Maritime Partner in Norway, which allows them to operate in rough seas,” Mr Hallock said.
“However, at four tonnes and more than eight metres in length, they will be too big to handle in the surf at Macquarie Island, so we’ll continue to deploy inflatable rubber boats to get people ashore in the sub-Antarctic.”
The tenders have plenty of redundancy built into them in terms of propulsion and navigation, with two five-cylinder diesel engines, separate fuel tanks, radar, GPS, chart plotter and an electronic identification system.
While the stern tender is identical to the personnel tenders, it is located at the stern of the ship for access to the pool of open water behind the ship when it’s locked in ice. This is important for safe helicopter operations and to support deployments of some scientific equipment over the stern.
Altogether, the three tenders offer a capability increase on the Aurora Australis, which doesn’t have dedicated embarked personnel transfer watercraft.
Similarly, the science tender will provide a new research capability that will work independently or in parallel with the Nuyina’s scientific systems.
“Its primary mission is to support science activities. It has a moon pool to deploy instruments through the hull, an A-frame to deploy towed bodies and a davit rated to deploy scientific instruments in rough seas,” Mr Hallock said.
The 10.3 metre-long, 3.5 metre-wide science tender also has a few mod cons including a heater, defroster, sink and toilet. The vessel will be operated by two Australian Antarctic Division personnel and will accommodate up to six personnel and 500 kilograms of cargo.
At the opposite end of the Nuyina, on the cargo holds’ hatch covers near the bow, will sit the two 16.3 metre-long, 6.2 metre-wide barges, each capable of carrying more than 45 tonnes of cargo.
Manufactured by Taylor Bros in Hobart, Tasmania, the barges can carry trucks loaded with shipping containers for a ‘roll on, roll off’ operation, or shipping containers and other cargo for a ‘load on, load off’ operation, using cranes on the ship and at the station wharf.
Icebreaker Project Manager, Nick Browne, said the aluminium barges can operate in calm seas and up to 50 knots of wind, at a speed of eight knots.
“The barges are not built for the open ocean, but to carry general cargo from ship to shore in Antarctica. They can operate in grease ice and they have rubber fenders that can be used to carefully nudge bergy bits out of the way,” Mr Browne said.
Each barge has two 448 kilowatt (600 horsepower) engines and a water jet propulsion system that provides greater manoeuvrability than propellers.
“The water jets are a proven technology in Antarctica,” Mr Browne said
“They draw in water under the hull and push it past the stern, generating thrust. When each jet is operated independently they provide good control for manoeuvring. Because there are no external propellers or protrusions below the hull, it means they can sit flat on the hatch covers of the cargo holds.”
The barges are a classic example of a highly complex system made to look simple, with design tweaks that ensure their ramps will cope with frequent heavy loads at a certain gradient in contact with the shore, and various tide heights. They can also fit a 40 foot container while still allowing crew to move between the container and the wheelhouse, rather than having a long walk around.
As an added complexity, all the vessels and their associated equipment need to operate in temperatures as low as −30°C and up to 45°C.
“It’s a challenge to meet this design criteria,” Mr Browne said.
“Fortunately we have in-house experts and naval architects who can provide advice on the performance of equipment and materials at these extreme temperatures, as well as the expertise of Taylor Bros on our landing barges currently in operation.
“As a result, our watercraft will be just as strong, reliable and capable in their roles as the Nuyina will be. They will be an integral part of the ship’s systems and key to Nuyina’s ability to support the Australian Antarctic Program for the next 30 years.”
Australian Antarctic Division