CBO details downsides of AUKUS sub sales

The Congressional Budget Office review this month of the Navy’s latest 30-year shipbuilding plan highlighted how the planned submarine sales to Australia under the AUKUS agreement are likely to lower total U.S. submarine operational years.

The Navy plans to sell an initial used Virginia-class submarine to Australia in 2032, a second used submarine in 2035 and a new construction submarine in 2038. This aims to help Australia update its submarine force and prepare for building and fielding its own class of SSN-AUKUS attack submarines in the 2040s.

Under AUKUS, the U.S. has committed to selling Australia three to five submarines, to hedge against production issues with the SSN-AUKUS. If the U.S. sells a fourth and fifth submarines, the Congressional Budget Office (CBO) said they would be new construction boats in 2041 and 2044. 

While the Navy’s shipbuilding plan discussed potential AUKUS sales for Australia, the report noted the Navy “does not address whether or when replacements for those submarines would be ordered.”

CBO also reiterated the submarine industrial base has been struggling to meet and rise to the rate of one Columbia-class and two attack submarines produced per year, let alone a higher rate to make up for future Australian sales. In November, Rear Adm. Jonathan Rucker, head of Program Executive Office Attack Submarines, confirmed the Navy expected to achieve a rate of 1.3 attack submarine construction at the end of 2024, compared to a goal of 1.5 per year.

“It would be very difficult and expensive for the U.S submarine industry to increase production of attack submarines while also building one Columbia-class ship per year. Columbia-class SSBNs are two and one-half times the size of Virginia-class SSNs, and the amount of work required to produce ships scales roughly with ship size. Moreover, SSBNs are the Navy’s highest acquisition priority. As a result, the sale of SSNs to Australia could reduce the number of attack submarines available to the Navy,” the report said.

CBO analyzed developed three scenarios to show how AUKUS could affect the Navy’s attack submarine force through 2060: the U.S. only selling the initial three planned SSNs without replacing them, selling five SSNs without replacing them, and selling five but also replacing them with extra submarines in the 2030s and 2040s.

A version of this story first appeared in Exchange Monitor affiliate publication Defense Daily.