Groton ― Shipyard equipment used in lowering submarines into the water at Electric Boat broke over the weekend, postponing a launching that had been planned next week, an EB spokesman confirmed Tuesday morning.

No damage to the submarine occurred and there were no reported injuries, Dan McFadden, EB’s director of communications and public affairs, wrote in an email.

“At about 4 a.m. Saturday morning, shipyard workers on Graving Dock 3 heard a loud noise from the launch pontoon ― a platform that lowers the submarine into the water,” McFadden wrote. “Subsequent investigation revealed a fracture in the metal deck of the pontoon.”

According to McFadden, PCU Iowa (SSN 797), a Virginia-class attack submarine, had been rolled out of an assembly building and onto the graving dock area next to the pontoon in preparation for the upcoming launch. (PCU, which stands for pre-commissioning unit, is a designation the Navy applies to vessels under construction prior to their official commissioning.) The submarine had completed the move to the end of the dock and was stationary at the time of the discovery.

“The submarine was never on the pontoon, and it was rolled back into the building, where construction and testing will continue,” McFadden wrote.

He indicated a full assessment of the damage and a repair plan for the pontoon is being developed in consultation with the Navy. The impact to the submarine’s construction schedule is being evaluated. A christening of the ship had been expected in April, though no specific date had been set, according to McFadden.

The Iowa’s keel-laying, a ceremony that marked the start of its construction, took place Aug. 20, 2019 at EB’s Quonset Point facility in Rhode Island.

b.hallenbeck@theday.com