BATH — Delivery of the first two Zumwalt-class destroyers to the Navy will be delayed by more than a year — a scheduling change that Navy officials attribute to the complexity of the ship’s technology and a lag in electrical work by shipyard workers because of that complexity.

But the president of the local union representing electricians said Tuesday that he doesn’t accept that reason. He noted that shipyard electricians worked six days per week for months and met goals set by the company for the Zumwalt-class ships.

As first reported Monday by Bloomberg, the first-in-class DDG 1000, the future USS Zumwalt, is scheduled for delivery to the Navy in November 2016 rather than September 2015. Delivery of the second “stealth” destroyer, the future USS Michael Monsoor, has been pushed back to November 2017, nearly a year after its expected due date of December 2016.

The third and final ship in the class, the future USS Lyndon B. Johnson, remains on schedule for delivery in December 2018.

“The schedule delay is due primarily to the challenges encountered with completing installation, integration and testing of the highly unique, leading-edge technology designed into this first-of-class warship,” Navy spokesman Cmdr. Thurraya Kent said in an email on Tuesday.

New technologies on the ship include a multifunction radar system designed to allow the ship to get closer to land without being detected, two advanced gun systems that fire Long-Range Land Attack Projectiles that can reach up to 63 nautical miles, an integrated undersea/anti-submarine warfare detection system and a vertical launching system.

“The shipyard performance in electrical trade work is behind plan due to complexity of the first-ever all electric ship and the particular demand it has created for skilled electricians shipyard-wide,” Kent said in a subsequent email.

That statement irked Jay Wadleigh, president of Local S6 of the Machinists union, the largest union at Bath Iron Works. Wadleigh said Tuesday that he “disagrees” with the idea that a lack of electricians was a factor, and he pointed to a proposal by shipyard President Frederick Harris a year ago to bring aboard electricians from another shipyard until BIW could train enough new hires.

Instead, union officials negotiated an alternative plan: More than 200 BIW electricians worked six days per week, including eight hours on Saturdays, to make up the extra work rather than bring on outside subcontractors.

Wadleigh said Tuesday that by “pushing everyone to the limit,” BIW electricians accomplished the work in the time required.

“No one thought we could do it,” Wadleigh said, “but we got there. Since then, they’ve been hiring, but it’s on again, off again. It seems like if there was this big shortfall, the hiring would have been constant.”

Shipyard spokesman Matt Wickenheiser declined to comment on Tuesday about how much the delay could add to the cost of the three Zumwalts, which Bloomberg estimated at $12.9 billion, or about $4.3 billion per ship. Kent did not return an email asking for that information.

“We’re working on a unique ship class that encompasses a lot of leading-edge technology in ways it hasn’t been used before,” Wickenheiser said Tuesday. “We always knew the really hard work would come as we got to the test and activation phase.”

Wickenheiser said the second ship also will be delayed in part because of a “chain effect,” but that BIW is taking lessons learned from the DDG 1000 and applying them to the second two ships.

The delay will not affect the company’s workforce, he said, which numbers about 5,700 — up from about 5,400 a year ago.

“We’ve been adjusting our work plan as we have gone along, and we are hiring in various trades,” Wickenheiser said.

Despite concerns about delays in delivery of the first two destroyers, speculation continues in the defense industry that the Zumwalt line — which is built exclusively by BIW — might be restarted.

The Navy chose to stop the Zumwalt line after three ships, citing exorbitant costs associated with building the new class of destroyers.

“It’s starting to look like General Dynamics (which owns BIW) is going to fight for the DDG 1000 production line — frankly, it’s a battle General Dynamics must wage,” said defense industry pundit Craig Hooper, a former vice president of BIW competitor Austal USA, on his blog, nextnavy.com. “They’ve invested far too much in Bath — making far too many DDG 1000 specific yard improvements to even consider stopping the DDG 1000 production line at three hulls. Canceling DDG-1000 is corporate suicide.”

Hooper wrote that he’d expected a fight for the Zumwalt-class destroyers ever since Harris assumed the helm at BIW in 2013.

He referred to a commentary, “ Canceling the DDG-1000 Destroyer Program was a Mistake,” in the January issue of National Defense Magazine. Hooper also mentioned an exchange between Sen. Susan Collins, R-Maine, and Chief of Naval Operations Adm. Jonathan Greenert at a March 4 hearing at the Senate Appropriations Subcommittee on Defense, during which Greenert praised the Zumwalt and said it is “a quantum leap in capabilities.”

Loren Thompson, a defense industry analyst at the Arlington, Va.-based Lexington Institute, said he would not be surprised by renewed interest in restarting the DDG 1000 line — particularly in light of the comments by Greenert.

“If the chief of naval operations speaks highly of a warship, I think probably there is a good political case for trying to buy more than three,” Thompson said. “(The DDG 1000) is inherently more capable in terms of how much equipment it can carry and how much power it can generate.”

Still, Thompson pointed to Senate hearings focused on funding the Department of Defense budget request, which does not include a fourth Zumwalt.

“The money would have to come from something else, because budget caps prevent adding to shipbuilding,” he said.

On Tuesday, General Dynamics stock prices fell 2.38 percent.