BATH – With President-elect Donald Trump demanding more ships, the Navy is proposing the biggest shipbuilding boom since the end of the Cold War to meet threats from a resurgent Russia and saber-rattling China.

The Navy’s 355-ship proposal released last month is even larger than what Trump had promoted on the campaign trail, providing a potential boost to shipyards that have struggled because budget caps that have limited money funding for ships.

At Maine’s Bath Iron Works, workers worried about the future want to build more ships but wonder where the billions of dollars will come from.

“Whether Congress and the government can actually fund it is a whole other ball game,” said Rich Nolan, president of the shipyard’s largest union.

Boosting shipbuilding to meet the Navy’s 355-ship goal could require an additional $5 billion to $5.5 billion in annual spending in the Navy’s 30-year projection, according to an estimate by naval analyst Ronald O’Rourke at the Congressional Research Service.

The Navy’s revised Force Structure Assessment calls for adding another 47 ships including an aircraft carrier built in Virginia, 16 large surface warships built in Maine and Mississippi, and 18 attack submarines built in Connecticut, Rhode Island and Virginia. It also calls for more amphibious assault ships, expeditionary transfer docks and support ships.

In addition to being good for national security, a larger fleet would be better for both the sailors, who’d enjoy shorter deployments, and for the ships, which would have more down time for maintenance, said Matthew Paxton, president of the Shipbuilders Council of America, which represents most of the major Navy shipbuilders.

“Russia and China are going to continue to build up their navies,” he said. “The complexities aren’t going to get any easier. The Navy, more than any of the services, is our forward presence. We’re going to need this Navy.”

Many defense analysts agree that military capabilities have been degraded in recent years, especially when it comes to warships, aircraft and tanks.

The key is finding a way to increase Navy shipbuilding to achieve defense and economic gains “in a fiscally responsible way that does not pass the bill along to our children,” said independent Sen. Angus King, a member of the Armed Services Committee.

Even when Trump takes office, no one envisions a return to the heady days during the Cold War when workers were wiring, welding, grinding, pounding and plumbing ships at a furious pace to meet President Ronald Reagan’s audacious goal of a 600-ship Navy.

The Navy currently has 274 deployable battle force ships, far short of its old goal of 308 ships.

Lawrence J. Korb, a retired naval officer and former assistant defense secretary under Reagan, said the Navy’s request isn’t realistic unless the Trump administration is willing to take the budget “to levels we’ve never seen.”

“You never have enough money to buy a perfect defense. You have to make trade-offs,” said Korb, senior fellow at the Center for American Progress.

But investors apparently are betting on more ships.

General Dynamics, which owns Bath Iron Works, Connecticut-based Electric Boat and California-based NASSCO, and Huntington Ingalls, which owns major shipyards in Virginia and in Mississippi, have both seen stock prices creep upward since the election.

“To the generic military shipbuilder, it’s a bull market right now,” said Ronald Epstein, an analyst at Bank of America’s Merrill Lynch division.

In Bath, the 6,000 shipbuilders aren’t going to count their chickens before they hatch.

“A lot of people are hopeful that it’ll happen,” Nolan said. “But they’re taking a wait-and-see approach. They’ve heard it before and then seen it not come to fruition.”