The Australian ambassador to the U.S. on Tuesday said the new AUKUS nuclear submarine trilateral security partnership aims to modify an existing submarine design and means to help the country project power more than use pure defense.

“We’ve got 12 to 18 months and we’re hoping to do it as quickly as possible to not have to use the full 18 months to determine what is the best design for Australia. And the Prime Minister’s being very clear and he was very clear to me when he was here that we had to build to an existing design,” Australian Ambassador to the U.S. Arthur Sinodinos said during a Hudson Institute event held on Nov. 9.

In September the U.S., U.K., and Australia announced the AUKUS partnership to help Australia procure new nuclear-powered attack submarines to replace its current fleet of six Collins-class diesel-electric boats. That also means Australia planned to cancel a pre-existing $90 billion program to replace the Collins-class with 12 conventionally powered submarines designed by France’s Naval Group.

“We didn’t want to spend years playing around with a design and so with our American and English partners, we’re going to get through that process of working it out,” Sinodinos continued.

He noted the existing design will be “calibrated for our scale and the levels of complexity that we can handle.”

The AUKUS pact is starting with an 18-month period where all three countries are working to help inform Australia how it will pursue its first nuclear-powered submarines.

Sinodinos compared the effort to using Legos, as they develop a series of steps to put the project together.

“We have to work out the workforce requirements, whether the education and technical requirements to go with that, the naval and nuclear stewardship requirements – what do we need to stand those up effectively.”

The ambassador said they have already conducted a due diligence process that satisfied the U.S. “that we could be trusted with the nuclear technology we’re talking about, but now we’re putting together the practical bits and pieces which actually mean that stewardship is available and then means we’re in a position to start acquiring submarines.”

In October, the U.K.’s chief of the defense staff, Gen. Sir Nick Carter,  said the two biggest challenges in this effort are pace and industrial capacity (Defense Daily, Oct. 19).

Earlier, in September, Chief of Naval Operations Adm. Mike Gilday said this Australian effort may take decades to complete before any of these new submarines go in the water (Defense Daily, Sept. 23).

Sinodinos said the Australian government intends for these new vessels to be built in the state of South Australia.

When asked what the country hopes the new submarines will add in capability, Sinodinos said this is not meant to cannibalize U.S. and U.K. submarine fleets or taking the next one that comes off the assembly line.

“This is about developing a capability which augments what is available to our license partners in the region. We went for this nuclear power submarine option because we can do it without having a civil nuclear industry, contrary to what some people say,” Sinodinos said.

He underscored the nuclear reactors aboard the submarines will stay in them for the life of the boats and they can be serviced offshore, if necessary.

“The important thing is their lethality, their range, the number of things they can do, and it’s part of a defense philosophy that we want to be able to – in this deteriorating strategic circumstances-  be able to project our power further up rather than taking an approach that all our defense has to be  defense of the mainland.”

Sinodinos emphasized the submarine strategy is about how Australia projects power and therefore be able to help shape the security environment they operate in the Indo-Pacific region, while China increases its military forces and throws its weight around.

This is in sync with statements Deputy Defense Secretary Kathleen Hicks made last month that these submarines will help build up capability to deter threats from China (Defense Daily, Oct. 1).