BATH, Maine — General Dynamics announced Monday that a new president would take the helm of Bath Iron Works effective Jan. 1, 2017.

Frederick J. Harris, 71, who has led the Bath shipyard for three tumultuous years, will retire as president of BIW and General Dynamics NASSCO, based in San Diego, according to a release from General Dynamics.

Dirk A. Lesko, 50, a 26-year employee of BIW and previously vice president of surface combatants and managing all programs, has been elected a vice president of the corporation and appointed president of BIW.

Kevin M. Graney, 52, has been elected a vice president of the corporation and appointed president of General Dynamics NASSCO. Graney was appointed vice president and general manager of NASSCO in November 2013.

“Dirk and Kevin are seasoned leaders with proven track records of managing complex shipbuilding projects and driving continuous improvement at every level of their business,” John P. Casey, executive vice president of Marine Systems, said in the release. “Both have worked for General Dynamics for more than 20 years and they have the right management and operations experience to ensure these shipyards are positioned for the future.”

In announcing the retirement of Harris, Casey said, “Throughout his extensive career with General Dynamics, Fred has held leadership roles at all three of our shipyards and made significant contributions to U.S. Navy’s shipbuilding programs. I want to thank Fred for his commitment to shipbuilding and outstanding service to our company and employees. We wish him well in retirement.”

In an internal memo to BIW employees Monday announcing the changes, Harris wrote that during the past three years the company had become more efficient, delivered “the most advanced destroyer ever built to our fleet,” and made nearly 200,000 improvements to the design of the DDG 51, the Arleigh Burke-class destroyer that has made up the bulk of BIW’s work for decades.

“You should be proud of these achievements,” he wrote. “Change is hard. It is also essential if Bath Iron Works is to build on its heritage and continue to provide good jobs for its employees and great ships for the nation’s men and women in uniform.”

Harris has steered the Bath shipyard, in addition to NASSCO, since former President Jeffrey Geiger left BIW to become president of General Dynamics Electric Boat on Nov. 4, 2013.

In a statement at the time, Casey said Harris would be “identifying and implementing creative ways to cost-effectively deliver state-of-the-art surface vessels … [and] find new opportunities to gain additional efficiencies across these already high-performance organizations.”

Harris said early in 2015 that he would focus on reducing costs at BIW in order to keep the company competitive for future projects, including the next generation of U.S. Coast Guard offshore patrol cutters — a contract BIW lost out on earlier this fall. Harris said at the time that the contract would avert laying off about 35 percent, or 1,200, of the Bath shipyard’s manufacturing employees.

Harris proposed hiring electricians from NASSCO in San Diego as BIW scurried to ramp up its own staff for new work. Instead, the union negotiated to allow more than 200 BIW electricians to work overtime “to keep NASSCO and Electric Boatyard out of our yard,” Jay Wadleigh, then-president of Local S6 of the machinists union, said at the time.

After a number of other proposals made by Harris to subcontract work, in March 2015, about 1,000 members of BIW’s largest union marched along Washington Street, outside the shipyard, to object to proposals by Harris including cross-training employees. In May, they marched up Washington Street again in protest.

“People are fed up with the way we’re being treated,” said Wadleigh in March. “I haven’t seen labor relations this bad since 2000.”

Three months later, a second union at BIW objected to a proposal by Harris to contract out work instead of filling vacant jobs to address a backlog of work. At the time, Dan Loudermilk, president of Local S7 of the International Association of Machinists and Aerospace Workers, said a meeting with Harris deteriorated into name calling and, after Harris “threatened to shut down the union,” Loudermilk said he left after refusing to shake Harris’ hand.

In December 2015, after long negotiations and with an eye toward winning the Coast Guard contract, Local S6 leaders approved a new contract that replaced annual pay raises with bonuses.

In September, BIW announced it would cut 160 jobs, including 30 layoffs, but said they were because of the typical ebb and flow of work on destroyers, and not related to failing to secure the Coast Guard contract.

On Monday, Rich Nolon, who remains president of Local S6 of the machinists union until the new president, Mike Keenan, takes over in January, said only, “Hopefully it’s a change for the better.”

Analysts agreed on Monday that, despite the controversies, Harris will leave large shoes to fill at the shipyard.

“Fred Harris is one of the most accomplished shipbuilders of his generation,” Loren Thompson of the Arlington, Virginia-based Lexington Institute said Monday. “The thing that really differentiates Bath from its competitors is the quality of its management team. This is a very tiughtly-managed operation.”

“It’s tough to use the word ‘legend,’ but I think Fred was viewed as somebody who really knew how to run a shipyard,” said Jay Korman, senior Navy analyst with the Washington, D.C.-based consulting firm The Avascent Group. “Overall, I don’t envy his successor, no matter who it is.

“[Lesko] has the experience to do it. He’s seen the yard from multiple vantage points, from business to finance, strategy, big management, so I think he’s the right guy for it,” Korman said. “I don’t know what he’ll bring that maybe hasn’t been put in place yet, but I’m eager to see how his leadership impacts the yard.”

In a joint statement Monday, U.S. Sens. Susan Collins and Angus King thanked Harris for his years at BIW and commended the choice of Lesko to lead the shipyard.

“We have both worked with Dirk very closely over the years and are confident that his depth of experience, proven track record, and longstanding commitment to the yard will make him a good leader who will work well with the talented and skilled employees at BIW,” the senators said. “We look forward to continuing to work with him in his new capacity to help position the shipyard for success in the future.”