Australia’s 4 Big Navy Workboats May Support ADF’s New Undersea Platforms

The Australian government has maintained quite an appetite for commercial Offshore Support Vessels. With little overt military value, Australia’s cheap-but-robust commercial workboats are subject to fierce debate. Though four are currently in Australian service, Australia’s strategic defense review offers little insight on the fate of these interesting “do-it-all” vessels.

As an active consumer of offshore support vessels, Australia focused on procuring some of the larger offshore support vessels on the market. It has acquired a diverse fleet of high-tonnage platforms. They’re all big, tough vessels, built to take whatever the Southern, Pacific, or Indian oceans throw at them.

To put the ships in perspective, they’re heavier than the U.S. Coast Guard’s big National Security Cutters, and clock in within only a few thousand tons of America’s early-variant Arleigh Burke class destroyers.

No stickler for a fancy design or special features, Australia’s super-sized 4-ship utility fleet is a foreign-built mix of both used and newly-built oilfield support vessels.

Australia bought the 8,500-ton Australian Border Force Cutter, Ocean Shield, right off the shipways as it was under construction in 2012. Builders completed the ADV Ocean Protector, now a Navy asset, in 2007, and the ship began Australian service in 2015. Australia procured the ADV Reliant, serving as a Pacific support vessel, in early 2022. It then purchased a fourth big OSV, a 7400-ton dedicated undersea support vessel, the future ADV Guidance, in late 2022.

Despite their obvious robust and ready utility, these are controversial vessels. Purchased for around $100 million US, they are relatively cheap—though each cost about the same it cost Australia to procure than the far-larger and more sophisticated HMAS Choules, a surplus Bay Class amphibious vessel that was handed over by the Royal Navy in something of a sweetheart deal.

Criticized for their seeming inability to project a large amount of support ashore, the austere utility ships address a range of Australia’s operational and personnel realities. In general, they host a small permanent crew of usually less than 50 sailors, but have accommodation to support over a hundred additional personnel if required. They all have a helicopter landing spot, but have no hangar to maintain a conventional rotary-wing platform for long voyages. They have large, stabilized cranes, but are unable to carry large amounts traditional amphibious assault-oriented cargo or gear employed in traditional “large-scale” amphibious operations.

Subsequent modifications may have eliminated some of the ship’s original features.

In general, the big utility boats are tough, robust craft. They are powerful and maneuverable enough to tow disabled vessels and can work in polar/arctic waters. They’re big enough to handle the open ocean and take on anything from heavy weather to misbehaving Russian or Chinese trawlers that may be temporarily “restricted in their ability to maneuver”.

For supporters of traditional amphibious vessels, these do-anything ships are, on the surface, poorly aligned with Australian strategy—to critics, they’re simply too big to engage Pacific island countries in an intimate way and of little use for disaster recovery. The suggested effort to de-emphasize Australia’s disaster support work, detailed in Australia’s Strategic Defence Review, also puts their future in some question.

Supporters point out that the fleet has been quite busy proving their detractors wrong. Australia’s ADV Reliant arrived in Sydney in August 2022, and then promptly deployed to the Pacific. In November, the ship was offloading humanitarian supplies to the drought-stricken Republic of Kirbati. In early December, it was tied up at Nuku’Alofa, Tonga, firming up disaster support plans with the strategically-placed nation, and showing off its landing craft support vessels and fresh-water support capabilities. By late December, it was visiting the Port of Apia in Samoa. In early 2023, the ship spent about a month supporting hydrographic, land and environmental surveys in the waters of Temotu Province, in the eastern Solomon Islands. That’s a pretty good operational record—and those stops are just a recounting of the ship’s publicized activities.

But even if the outreach and disaster support missions go away, each support vessel has—or had—substantial undersea capabilities. ADV Reliant was built with a moon pool, and sports a crane that can reach 3,000 meter depths. Both ADV Ocean Protector and the future ADV Guidance were built with a 23 by 23 foot moon pool, likely large enough to handle Australia’s Ghost Shark unmanned undersea vessel Prototype, Anduril’s 19 ft Dive LD autonomous undersea vehicle.

With Australia’s purchase of three Dive LD prototypes, and with at least three Navy ships sporting good-sized moon pools in the Australian fleet, it’s a good guess as to which Australian ships might be tapped to support a number of rapid undersea vehicle test-and-prototype campaigns. By juggling maritime engagement, disaster support and high-tech testing, these ships may prove a particularly good fit with Australia’s future “move-fast-and-break-things” defense strategy.