Coast Guard icebreakers Polar Sea and Polar Star in the ice channel near McMurdo, Antarctica. (USCG photo by Rob Rothway.)

WASHINGTON — An independent government watchdog estimates the U.S. Coast Guard’s program to build three new heavy icebreakers will cost about $5.1 billion, 60 percent more than the agency’s current projections of $3.2 billion.

These figures come from a new report by the Congressional Budget Office, commissioned by the House Homeland Security Committee and released today.

“CBO estimates that operating and supporting a force of three (Polar Security Cutters) between 2029 and 2063, when these vessels are in service, would cost $12.4 billion,” the new report said. “If the Coast Guard acquires more than three vessels, operating costs would be higher and incurred over a longer period of time.”

RELATED TOPIC: ICE Pact: Why the US had to seek help in the race with Russia and China for Arctic icebreakers

It is common for the CBO and the Coast Guard or Navy to disagree on the expected price of a future vessel. These differences arise from assumptions that analysts must make about inflation, material costs and other future economic variables. In its report, the CBO states that the Coast Guard is in the process of calculating a new cost estimate and plans to release those figures later this year.

What makes predicting the price of the Polar Security Cutter even more difficult, however, is that analysts often use existing ships as the basis for their model calculations of how much a future vessel should cost. In this case, the United States hasn’t built a heavy icebreaker in more than four decades.

To conduct its analysis for lawmakers, the CBO chose to use the only operational American heavy icebreaker, Polar Star, the U.S. Coast Guard’s medium icebreaker Healy, and the Navy’s San Antonio-class amphibious warfare ships.

“None of these analogs are ideal for the analysis,” the CBO said. “As a heavy icebreaker, the Polar Star appears to be the most suitable, but it is also the oldest of the ships, having been completed in 1976. The Coast Guard was therefore unable to provide a cost history of the ship. The Healy was completed in 2000, but is a medium icebreaker and thus not designed for quite the same missions that the PSC will perform. The LPD-17 (San Antonio class) ships still in production are almost the same size as the PSC.”

RELATED: Why a small shipyard merger could mean bigger problems for the U.S. military

The Coast Guard selected VT Halter Marine from a large field of other shipbuilders to build the Polar Security Cutter in April 2019. In December 2021, the Coast Guard exercised a contract option to begin work on the second vessel in the class. Since then, Bollinger Shipyards of Louisiana has acquired VT Halter Marine and assumed control of the program.

The CBO report comes just weeks after the Biden administration announced a new security agreement with Canada and Finland during the NATO summit, called the ICE Pact, aimed directly at strengthening the icebreaker fleets of all three countries. Leaders promised at the initial announcement that a joint memorandum of understanding with more concrete plans would be presented later this year, but administration officials have said the Coast Guard, Pentagon and Bollinger will all play a role in the new agreement.