BRUNSWICK — Bath Iron Works celebrated construction of a new warship Friday with U.S. Sen. Susan Collins in attendance.

The ceremony marked the start of construction of the future USS Patrick Gallagher, an Arleigh Burke-class destroyer named for an Irish-born Marine who was awarded the Navy Cross, while another destroyer left to join the Navy.

Collins, who is credited for helping to secure funding, spoke to shipbuilders at the Hardings facility, where large pieces of metal are fabricated in Brunswick. With help, she operated a massive plasma-cutting machine to begin transforming the first piece of metal for the ship.

She praised the work of the shipyard’s 5,700 workers, telling them that sailors repeatedly tell her that they prefer to work on Navy ships built by Bath Iron Works.

“It does make a difference to the crew of our ships to have a Bath-built ship,” she said. “It’s not just a slogan that ‘Bath-built is best built.’ It is the truth. It is the reality.”

The Harding facility will be the beneficiary of much of the $100 million in improvements that the General Dynamics subsidiary is planning over the next few years. The building will be redesigned, and there will be new cutting machines, burning tables, and blast and paint facilities.

The large pieces that are created at Harding are then transported to the main shipyard in Bath where they’re assembled into high-tech warships.

One of those warships, the future USS Michael Monsoor, departed the shipyard on Friday for the final time. The ship is the second of three stealthy destroyers built in Bath.

The Monsoor, named for a Navy SEAL who threw himself on a grenade to save comrades, is due to be commissioned in January in Coronado, California.