U.S. Sen. Angus King speaks to Bath Iron Works employees to celebrate the christening of the USS Harvey C. Barnum Jr., the shipyard’s 40th Arleigh Burke-class destroyer, on July 29. Jason Claffey / The Times Record

Representatives of Bath Iron Works’ largest union on Monday announced a tentative contract agreement in the first negotiations since the union went on strike in 2020.

Machinists Union Local S6 represents about 4,250 of the shipyard’s 6,500 workers. The three-year agreement, which union members will vote on by Aug. 20, includes pay raises, an increase in BIW’s contributions to pension plans and higher health insurance premiums. A $1,200 ratification bonus for workers in the previous contract was not included in the agreement.

The pay raises range from 4% to 9.5% in the first year of the contract, 5% in the second year and 4% in the third year. BIW pension contributions will increase about 2.5% each year of the contract, while health insurance premiums for workers will increase about 4% per year.

“The substantial wage and benefits package is a clear indication that our company believes in its current workforce and wants to continue to attract new talent to sustain our work into the future,” BIW said in a statement. “Negotiations provide an opportunity for BIW to listen to and strengthen relationships with our key workforce partners. The professional and respectful tone and tenure of the discussions at the negotiation table with Local LS6 emphasized the importance of building on the momentum in the shipyard and seeking continuous improvement.”

A union representative could not be reached for comment Monday. In a recent statement, the negotiating committee said the contract talks were going “smoothly and professionally.”

The union’s negotiating committee and representatives from General Dynamics, which owns BIW, started talks July 26 and the union quickly announced a tentative agreement over subcontracting, an issue the union went on strike over in 2020.

The new contract would go into effect Aug. 21.

The 2020 strike slowed the shipyard’s production by months. BIW President Chuck Krugh, who was hired in 2022, said workers have been ramping up production. The shipyard was recently awarded a Navy contract to build three more Flight III Arleigh Burke-class destroyers. Twelve destroyers are now in the works at the shipyard.

BIW and Ingalls Shipbuilding in Mississippi are the only yards that build Arleigh Burkes, and they compete for contracts. Ingalls, which has more than 11,000 workers and builds a variety of ships, was recently awarded a contract to build six destroyers.