The US Navy’s ambitious plan to replace its aging Ohio-class submarines with immature technology in the next-generation Columbia-class subs faces the same problem as the F-35 has for so many years: undeveloped technology presenting greater risk for schedule delays and cost overruns.

The US Government Accountability Office, a government watchdog agency, warns that a number of the submarine class's nascent technologies, including the integrated power system, nuclear reactor, common missile compartment and propulsor, comprise risks that could delay delivery of the underwater vessels.

"It is unknown at this point whether they will work as expected, be delayed, or cost more than planned," the report states, adding that "any unexpected delays could postpone the deployment of the lead submarine past the 2031 deadline."

The Navy evidently doesn't have a mandate to report its progress on technology developments to Congress until 2020, when "$8.7 billion for lead ship construction will already have been authorized." The agency suggest that periodic reporting on technology efforts could provide lawmakers more peace of mind when the Navy asks Congress to authorize more funds for what the government considers a "top priority."

The Columbia-class submarines will ultimately be armed with 70 percent of America's strategic nuclear weapons, according to GAO. The Navy plans to commission 12 such submarines to replace the 14 existing Ohio-class subs, which were built between 1976 and 1997.

"We can't push [this] off any further, even if there is some risk as we push forward," Thomas Callender, a retired submarine operator and current Heritage Foundation analyst, told Defense News Thursday. "We don't have any choice, and I think everyone knows the stakes here," the analyst noted.

General Dynamics was awarded $5 billion to complete design work on the subs in late September.

The total program cost of about $267 billion — as well as its vulnerability to downstream cost growth — has the potential to substantively change the tactical landscape for the US Navy. With such a costly, high-priority program, the Navy may be forced to cut back on plans to grow the fleet or reduce operational tempo.

"Observers are concerned about the impact the Columbia-class program will have on the Navy's ability to fund procurement of other types of ships at desired rates in the 2020s and early 2030s," the Congressional Research Service said in a September 14 brief.