A new Navy report ambitiously predicts that in the distant future the service will buy many more surface combatants, plus other warships, without boosting the 30-year shipbuilding plan’s average annual funding.

At issue is the production schedule for a notional destroyer called DDG(X), which the department wants to buy about two decades from now to replace existing DDG-51 destroyers.

(The DDG(X) is different than the DDG-1000 program, which is a near-term effort to build seven destroyers, mostly at a rate of one per year.)

Last year’s report to Congress predicted the Navy would buy only two DDG(X)s per year between fiscal years 2025 and 2036. But the new report, issued this month, increases that construction rate to three per year.

This change adds a dozen or so DDG(X)s in the most distant and least meaningful years of the plan without increasing the average amount of money earmarked to implement shipbuilding goals.

Although the charts in the report provide only a general overview of procurement rates for kinds of vessels (as opposed to specific classes) Navy spokesman Lt. Bashon Mann confirmed the plan would begin DDG(X) procurement with the lead ship in FY-23, followed by two ships in FY-24 and three ships annually between FY-25 and FY-37.

Ronald O’Rourke, a defense analyst with the Congressional Research Service, told Inside the Navy this change “significantly” reduces a long-range cruiser-destroyer shortfall that was the “biggest deficiency” in last year’s long-range report.

This adds 12 or 13 DDG(X)s to the plan, “depending on whether you include FY-37 in the count,” he said. The added ships address “about one-half of the 26-ship deficiency in cruisers and destroyers in last year’s plan,” he said.

“At a hypothetical cost of about $2 billion each, 12 or 13 DDG(X)s would cost roughly $25 billion, or an average of about $830 million per year in additional funds over a 30-year period,” he said.

Though the new report aims to buy more destroyers and make other changes, it does not increase the average annual shipbuilding funding projections.

“Although the Navy added a net total of eight to 11 ships -- depending on whether you include the non-overlapping years of FY-07 and FY-37 -- it does not seem to have increased its calculation of the average annual funding required to implement the plan,” he said. “It’s still $13.4 billion per year in FY-05 dollars.”

He added, “Looking at the ships that were added and subtracted, the net additional eight to 11 ships might have increased the average annual cost of the 30-year program by roughly $500 million or more. If the Navy isn’t taking steps beyond those already announced last year to reduce the procurement costs of ships in the plan, then the Navy’s unchanged cost calculation implies that the DDG(X)s will be substantially less expensive than was assumed under last year’s plan.”

Asked whether buying more DDG(X)s is affordable, Mann said the report takes into consideration affordability as well as other factors. The plan is subject to change in the future, he said.

O’Rourke also cautioned that the cost calculations in the new Navy report might not include the impact of recently revealed cost growth in the Littoral Combat Ship program.

“If LCSs turn out, for example, to cost an average about $50 million more to build than what was previously estimated, then a 55-ship LCS program might now cost about $2.75 billion more than previously estimated, or an average of about $90 million more per year over a 30-year period,” he said.

Few adjustments otherwise

Much of the 30-year plan closely resembles last year’s version.

The new document makes no changes to the aircraft carrier procurement schedule for the next three decades.

The overall procurement schedule for attack submarines is unchanged.

But there are other changes.

For instance, the procurement of the first submarine in a new yet-to-be-defined class of ballistic missile subs has been accelerated from FY-22 to FY-19, which could be intended to provide more work for the struggling industrial base of submarine designers. The new schedule puts the second such sub in FY-22, with none in FY-23 and one annually from FY-24 to FY-35.

The vast majority of construction plans for the Littoral Combat Ship are unchanged, except for minor adjustments in the FY-31 to FY-33 period. The Navy does not count these vessels as traditional surface combatants.

For amphibious assault vessels, referred to in the report as expeditionary warfare ships, the report deletes an LHA-6 class ship previously planned for FY-10. Among other changes, the report accelerates procurement of the next expeditionary warfare ship from FY-18 to FY-17.

The report also revises long-term procurement plans for combat logistics ships.