Keeping the task group on task

With no commercial floating petrol stations in the middle of the ocean, Royal Australian Navy ships and helicopters rely on specialized replenishment ships for all their fuel needs.

Underway refueling is called replenishment-at-sea (or RAS), which requires a number of complex maneuvers that requires ships to maintain a steady course and speed for a number of hours.

The Australian Navy has two underway replenishment ships, HMAS Ships Sirius and Success – which with the support of similar Allied vessels, keeps the Australian Navy steaming across the globe.

For a task group deployment such as Indo-Pacific Endeavour, currently away across the region, self-sustainment is key, and in this case Sirius is on task.

Commanding Officer Sirius, Commander Michael Oborn said he was proud of the vital capability his ship and crew could provide to the rest of task group and other Allied ships in the region.

“Replenishment at sea is the closest any two ships will ever come to each other while out in the open seas, we are only 50 metres apart,” Commander Oborn said.

To start the process, the ship receiving the fuel will fire a thin line, or rope, across to Sirius before hauling back a heavier line to establish a taut ‘flying fox’ arrangement between the two ships, called a span wire.

The span wire is tensioned by Sirius, then the fuel line slides across to the receiving ship and attached to the ship’s fuel tank with the crew watching the tension and fuel lines.

“Sirus will typically transfer anywhere from 100,000 liters up to 10,000,000 liters to a receiving ship, at a rate of up to 600,000 liters per hour,” Commander Oborn said.

”Obviously the amount of fuel transferred is dependent on the amount of fuel the receiving ship needs, and the bigger the ship, generally, the more fuel required.”

At this point the ship’s release the lines before going their separate ways to the tune of the receiving ship’s selected replenishment song.

“We have recently conducted multiple replenishments with HMAS Melbourne and HMAS Parramatta who have capacity to hold about half a million liters of fuel each,” Commander Oborn said.

And if you thought two ships maneuvering closely at speed whilst connected sounded difficult, try having one on each side, as Sirius did in September, refueling HMAS Darwin and Melbourne simultaneously while underway, as the task group sailed off the north coast of Australia.

The ship can carry over 34,806 cubic metres of fuel including 5,486 cubic metres of aviation fuel for use by helicopters. She can replenish ships at sea by day and night, and has transfer points for fuel, water and stores.

“There is no need to worry about Sirius running out of fuel as she carries enough fuel to run all the cars in Perth for more than a month,” Commander Oborn said.

All in a day’s work in combat logistics.