The new class of nuclear-armed ballistic missile submarines will feature several new technologies intended to increase their survivability.

But a new report from the Government Accountability Office found that further testing and development of those technologies, which are critical to performance, are needed to avoid any delays or increased costs to the program.

"As a result, it is unknown at this point whether they will work as expected, be delayed, or cost more than planned," the report says.

The Columbia-class submarines will carry 70 percent of the U.S.'s active nuclear arsenal once in service, and are replacing the 14 Ohio-class submarines set to retire beginning in 2027. The first Columbia submarine isn't expected to go on patrol until 2031. The submarines are expected to serve well into the 2080s.

While the submarines, currently in the advanced design stage, will include many of the same components as Virginia-class attack submarines, they also will have new technologies, including those used in the submarines' integrated power system, nuclear reactor and common missile compartment.

"GAO is right to flag them as critical parts of Columbia that really have to be watched like a hawk because there's no margin for delay," said U.S. Rep. Joe Courtney, D-2nd District, ranking member of the seapower subcommittee of the House Armed Services Committee.

Federal lawmakers anticipated GAO's concerns and inserted language in the 2018 defense policy bill requiring the Navy to report more frequently on the program's progress. Under existing law, the Navy is not required to provide Congress with an update until fiscal year 2020, when, the report notes, $8.7 billion for construction of the lead ship already will have been authorized.

"Periodic reporting on technology development efforts in the interim could provide decision makers assurances about the remaining technical risks as the Navy asks for increasing levels of funding," the report says.

The defense policy bill stipulates that the Navy report on the program's progress every year, starting next year.

"The program needs as many eyes on it as it can possibly bring to bear to identify any risks and problems as early as possible to keep the timeline on track," Courtney said.

William Couch, a spokesman for Naval Sea Systems Command, said the Navy actively manages the program's cost, schedule and performance goals, and routinely briefs military leaders and Congress to ensure risks are transparent and fully understood.

The program, a top priority for the Navy and the Department of Defense, is expected to cost $267 billion over its life cycle, including $128 billion to research, develop and buy the 12 submarines. Electric Boat is the prime contractor for the Columbia program.

The Navy intends to complete much of the submarines' overall design before starting construction to reduce the risk of increased costs or delays, which is consistent with GAO's best practices.

However, the report notes, "the Navy recently awarded a contract for detail design while critical technologies remain unproven. ... Proceeding into detail design and construction with immature technologies can lead to design instability and cause construction delays."

j.bergman@theday.com