As construction ramps up on a new class of ballistic missile submarines, a congressional watchdog says the reliance on a smaller and less mature supplier base than existed during previous shipbuilding booms remains a top vulnerability for the program.

The report from the Government Accountability Office released publicly this month outlines the challenges faced recently by the estimated $128 billion Columbia-class submarine program.

In addition to the supplier issues, “continuing challenges” with the computer-aided software tool that Electric Boat is using to design the Columbia submarines pose a risk for cost overruns and delays, the report says.

Liz Power, spokeswoman for EB, said the information contained in the report is “based on a snapshot of our progress more than a year ago.”

“While we faced early challenges with our design tool, those have been resolved over the past year,” Power said in an emailed statement. “We achieved our plan for design completion as well as the on-schedule October 2020 construction start on the Columbia class.”

When construction started on the first Columbia submarine, known as the lead ship, in the fall of 2020, “we were at a level of design maturity higher than any previous submarine program,” Power said.

Over the next 20 years, EB plans to construct and deliver 12 Columbia submarines while also continuing to build Virginia-class fast-attack submarines, the report says, “at a schedule and pace unmatched since the end of the Cold War.”

To do this unprecedented work, EB and Huntington Ingalls Shipbuilding in Virginia, the nation’s two nuclear shipbuilders, must rely on materials produced by a supply base that is roughly 70% smaller than in previous shipbuilding booms, the report says. That’s resulted in increased reliance on sole-source companies and a reduced number of suppliers that compete for contracts.

The report also details defective welds found several years ago on missile tubes that were to be installed on the submarines, causing delays to early construction work.

“As the shipbuilders expand outsourcing to suppliers, quality assurance oversight at supplier facilities will be critical for avoiding further delays,” the report says.

Congress in recent years has appropriated more funding to help expand and prepare the supply base.

With the support of Congress, EB has made “significant investments” in its suppliers to ensure they are prepared to handle the workload required to concurrently build the Virginia and Columbia classes of submarines, Power said.

U.S. Rep. Joe Courtney, D-2nd District, who chairs the congressional subcommittee with oversight of Navy shipbuilding, said while he welcomes “any visibility” on the Columbia program given its price tag, much of the issues have since been resolved.

“I really think these issues are in the rearview mirror at this point,” he said.  

Last year, Courtney advocated to restore a second Virginia-class submarine in the fiscal year 2021 defense budget, which has been the status quo since 2011. The restoration of the submarine provides stability to the supply chain so it can make investments such as hiring additional workers and buying materials, he said.

“Any time there’s instability in the program, that scares away supply chain firms,” he said.

j.bergman@theday.com