AUGUSTA — Bath Iron Works’ largest union narrowly approved a new contract Sunday that could put the shipyard in a better position to land shipbuilding contracts in the future.

The vote on the contract, which requires workers to make concessions on work rules, pay, pensions and health benefits, was fairly close, with 1,343 in favor of ratification and 1,045 against.

Machinists Union Local S6, which represents 3,600 workers, voted on a four-year contract that both sides said they hope will make the company more competitive in the future. The new contract changes work rules so that shipbuilders can perform additional tasks outside their specialties and some work can be outsourced to subcontractors. The former contract was not due to expire until May.

Jay Wadleigh, Local S6 president, expressed surprise at the outcome of the vote. He said few members were happy with the contract provisions and most endorsed it only reluctantly.

“Although it did pass by a narrow margin, the vote is in no way indicative of the feelings of the people. Only a few people were happy with the contract, but the majority were not,” said Wadleigh.

The shipyard said after the vote that the new contract will help make the company more competitive.

“General Dynamics Bath Iron Works is extremely pleased that this new contract was ratified by the men and women of … Local S6,” said Matt Wickenheiser, spokesman for the shipyard.

“This agreement will help make BIW more competitive as we seek to win new work so we can continue to provide good-paying jobs here in Maine. We look forward to working with the union to effectively implement the important changes in this agreement.”

The contract changes were essential to BIW’s ability to land future military contracts, management said.

Although the former contract wasn’t due to expire for another six months, the shipyard, a subsidiary of General Dynamics, started discussions early with the union in order to gear up to make a bid in March for a 20-year, $10 billion contract for up to 25 Coast Guard offshore patrol cutters.

The shipyard’s managers say clinching the Coast Guard contract would avoid as many as 1,200 layoffs, or one-fifth of the shipyard’s 6,000 workers. The shipyard, one of Maine’s largest employers, hasn’t built a Coast Guard ship since the 1930s.

The new contract calls for workers to give up pay raises in lieu of $2,500 annual bonuses, modest increases in pension contributions and higher employee health care deductibles and co-pays.

Parts of the contract start immediately and others will be phased in.

Voting was at the Augusta Civic Center, where the prevailing sentiment outside appeared to be against the new contract. Some people said they expected the contract would go up in smoke.

Frank Hiles, 34, of Bath, a 12-year employee, said he planned to vote against the contract because of its no-raise provision.

“It seems like everybody is going to shoot this down and see what we get in May,” Hiles said.

Darrell Damboise of Falmouth, a 28-year employee, said he had concerns about retirement provisions in the contract and paid time off.

“Everything I’ve seen so far from their side has been taking from us and giving us nothing. Just like negotiating a deal on a new car, I don’t believe this is their best offer,” Damboise said.

Terry Czosnek, of Auburn, 34, a six-month employee, said he was on the fence on how he would vote, but sentiment among younger or newer workers was generally in favor of the contract, partly because their memories of other, lesser-paying jobs are still fresh.

“Guys who have been here for 30 years, this is all they know,” Czosnek said. “I’ve worked some sketchy jobs for $9 an hour. This is the state of Maine; this is a great job. It’s hard to find a job that pays you well and gives you great benefits. This is the first time in my life that I’ve had life insurance by myself.”

Michael Sewell Jr., who has been with BIW for five years, said he voted in favor of the contract.

“It’s a great contract for our time right now,” considering the economy, Sewell said.

Sewell said he would rather take the contract as it is written than take any chances that it might get worse if union members opted to negotiate further.

Relations between the union and management were strained leading up to the vote. The two sides had been in arbitration.

Local S6 went on strike at the shipyard for 55 days in 2000. There was no talk of a strike this time.

Maine’s U.S. senators applauded the approval of the contract by the union.

“The ratification of the labor contract required collaboration, hard work, and compromise by all parties,” Sens. Susan Collins and Angus King said in a joint statement. “This represents a significant achievement and will put BIW on a viable track moving forward as they work as a team to fulfill critical Navy requirements.

“Bath Iron Works and its highly-skilled workers are national strategic assets essential to our country’s defense and to our state’s economy,” the senators added. “Simply put, there is no workforce better able to build the Zumwalt and Arleigh Burke-class destroyers than the men and women of BIW. We have secured funding for the construction of the DDG-1000s and the DDG-51s, and we remain strong advocates for BIW’s opportunity to compete for the construction of the Coast Guard’s new Offshore Patrol Cutters, which would diversify BIW’s workload, and make the yard more competitive for future Arleigh Burke destroyer contracts.”

After Sunday’s vote, Wadleigh said the union had done its part for the future and now it is time for the management to step up to the plate.

“We have done what we need to do. Now we need the company to manage us correctly to win these future contracts. We made some fairly major concessions and now we need for them to look at the overhead and get us the materials to get our rates down and beat our competitors,” Wadleigh said.

Press Herald staff photographer Ben McCanna contributed to this report.