With a union vote looming Wednesday in Washington state over production of a new Boeing jet, the aerospace giant broke ground Tuesday on a new plant in North Charleston to build engine components for a different airplane.

Union vote

All eyes will be on Washington state today Wednesday as the Machinists union votes on a proposed labor agreement with Boeing.

The International Association of Machinists will vote through 6 p.m. Pacific time on an eight-year contract that would ensure labor peace through 2024. The current contract ends in 2016.

The agreement calls for concessions by the union on pension and health care benefits. It also offers members a $10,000 signing bonus and other carrots to get them to vote for it.

Media reports out of the Evergreen State suggest the vote will be close.

The governor on Monday signed into law an $8.7 billion package of tax breaks and other incentives to ensure production of the new Boeing 777X stays in Washington state.

If the union rejects the deal, Boeing said it will explore options to build the plane elsewhere.

Jack Jones, Boeing South Carolina’s top executive, declined to comment on whether the 777X could be built in North Charleston, though he noted that parts of the plane will be designed in the Lowcountry. He said Tuesday that the decision is now the union’s hands, and he would not speculate further.

Boeing and other officials grabbed shovels and ceremoniously turned dirt on the start of a new 225,000-square-foot building in Palmetto Commerce Park where engine inlet parts will be designed and assembled for the 737 MAX and possibly future airplanes.

Propulsion South Carolina, as it’s being called, will sit behind Boeing’s Interior Responsibility Center on Patriot Boulevard where workers make bins, partitions and other cabin parts for the 787 Dreamliner.

Construction on the nearly 60-foot-tall structure will take about a year, and the 48-acre site can accommodate future expansion up to 600,000 square feet, according to Boeing officials.

The first parts are expected to be produced in May 2015 and the plant will eventually ramp up for components to be produced for 47 planes per month, said Charlie Hix, director of Propulsion South Carolina.

Hix added that if workers build 737 MAX engine parts without any problems, on time and at cost, then South Carolina could see work on other planes.

“If we’re successful here, we will earn the rights to future work,” Hix said.

The plant will include high bays, low bays, offices, support space and parking for 300 vehicles. If it’s expanded, it could handle another 400 parking spaces.

“Today we break ground, but what we are doing is ground-breaking,” said Nicole Piasecki, vice president and general manager of Boeing’s Propulsion Systems Division.

“We are investing in new capabilities for our company. Propulsion South Carolina will be at the heart of the action. We are redefining the future and delivering a wake-up call for our industry.”

The company announced the propulsion factory earlier this year. It will handle the engineering and assembly of the 737 MAX nacelles, which include the circular inlets and carbon-reinforced composite pods that encase the engines.

The plant is Boeing’s first major investment in South Carolina not associated with the 787.

The company has not announced the number of jobs the new plant will create, except to say they are part of the 2,000 new positions and the $1 billion investment Boeing will make over the next eight years.

The 737 MAX is the updated version of Boeing’s top-selling, single-aisle jet.

The Chicago-based aerospace giant employs about 6,100 workers in the region. Most are based at its 787 Dreamliner factory at Charleston International Airport.

“We are excited to see this new piece of Boeing for us,” North Charleston Mayor Keith Summey said. “We hope they will be successful, and we hope it will lead to more Boeing in the future.”

Reach Warren L. Wise at 937-5524 or twitter.com/warrenlancewise.