Collins Class Submarine Replacement Project - Possible Designs and Planned Capabilities

Possible Designs and Planned Capabilities

In the 2009 Defence white paper, the replacement submarine had been outlined as a 4,000-ton vessel fitted with land-attack cruise missiles in addition to torpedoes and anti-ship missiles, capable of launching and recovering covert operatives while submerged, and carrying surveillance and intelligence-gathering equipment. It is likely that the submarines will be fitted with the United States AN/BYG-1 combat system.

There are four possible routes for the SEA 1000 project to take, in order of increasing complexity and risk:

• Buy a Military-Off-The-Shelf (MOTS) design without modification
• Buy a MOTS design, but modify it for Australian service conditions
• Design an evolution of an existing submarine
• Design an entirely new submarine

Designs considered for the two MOTS routes include the Spanish S-80 class, the French-Spanish designed Scorpène class, the German-designed Type 214, and Japan's Sōryū class. Scaled-up proposals of the S-80 and Scorpène classes, as well as the Type 216 (an enlarged version of the Type 214) have been offered by the respective designs' parent companies as possibilities for modification. An updated version of the Collins class design is also being looked at: the original submarine was designed for the RAN's unique operating environment, and replacing or fixing the issues that affected the original submarines while updating equipment and systems would result in a design that meets the white paper requirements. SEA 1000 will most likely follow the 'modified MOTS' or 'evolution' path. No existing MOTS submarine design meets the RAN's desired capabilities, or would successfully operate in the warm seas and huge transit distances of Australian service. MOTS submarines were initially ruled out by the project in March 2011, but were put back on the table in December 2011. At the other end of the scale, designing a submarine from first principles is considered incredibly risky.

The Australian government has rejected nuclear propulsion. Reasons for the rejection include the lack of a nuclear power industry and the related infrastructure and regulatory guidelines (Australia would be the only non-nuclear nation to operate nuclear submarines), as well as public opposition to nuclear technology. Defence commentators have suggested that the United States Navy's Virginia class nuclear-powered submarines would fit the outline given in the white paper. But instead the recent defense technology deal could see Australia adapt the AIP technology of the Sōryū class submarines.