Cost of new submarine could threaten Navy fleet expansion.

• Author: Harper, Jon

The Navy's Columbia-class ballistic missile submarine program recently reached a key milestone. But questions remain as to whether the service will be able to afford the fleet expansion that it envisions if the submarine program is fully funded.

The Pentagon plans to build 12 new SSBNs over the next two decades to replace the aging Ohio-class boats. The Navy estimates that the total acquisition cost will be approximately $100 billion, in calendar year 2017 dollars.

In January the program successfully completed Milestone B, which granted the Navy authority to continue into the engineering and manufacturing development phase of the program and commence detailed design work.

Although the Defense Department is operating under a continuing resolution, Congress approved an "anomaly" for the Columbia program for fiscal year 2017 and appropriated $773 million for the project.

"The appropriation of [shipbuilding funds], the completion of Milestone B and transition to detailed design are the critical components to making sure that program remains on track," Rear Adm. Michael Jabaley, program executive officer for submarines, said at the Surface Navy Association's national symposium.

Construction of the lead boat is slated to commence in fiscal year 2021. The Navy hopes to have it on patrol in fiscal year 2031 as the Ohio-class is phased out.

Meanwhile, President Donald Trump has called for a 350-ship Navy. And the service released a new force structure assessment calling for a 355-ship fleet, a major increase from the previous goal of 308 ships. There are currently 274 battle force ships in the inventory.

"If you want to go down the path of the 350-ship Navy, you're going to have to buy a lot more ships" than the 2017 shipbuilding plan called for, said Eric Labs, a budget analyst with the Congressional Budget Office's national security division.

Such a buildup would come with a hefty price tag. Achieving a fleet of approximately 350 ships would cost an average of $25 billion per year over the next 30 years, or about 60 percent above the historical average for annual shipbuilding spending, according to CBO estimates.

The Navy is slated to procure a variety of new assets including aircraft carriers. But Adm. John Richardson, the chief of naval operations and the former commander of submarine forces, has identified the Columbia as the service's top acquisition priority.

Jabaley told National Defense he's confident that the envisioned fleet expansion...