A $2.8 Billion Nuclear Submarine Just Pulled Into Boston Harbor for the First Time in Decades

The Newest and Oldest Warships in America Were Just in the Same Harbor

A $2.8 billion nuclear-powered attack submarine sat docked at the Conley Shipping Terminal in South Boston this morning while the USS Constitution, the oldest commissioned warship in the U.S. Navy, sailed out of the Charlestown Navy Yard to meet it.

The USS Constitution fired a 17-gun salute as it passed.

That visual alone carried the weight of the entire event. The Navy’s first ship and its newest, separated by more than two centuries of naval warfare, floating side by side in the same harbor.

“In that moment, in one visual, there will be none older, none newer, none better, and none finer than the duo of the USS Constitution and the USS Massachusetts,” said Dinis Pimentel, chair of the USS Massachusetts Commissioning Committee.

Thousands packed the waterfront. Governor Maura Healey proclaimed it “USS Massachusetts Day.” The crew boarded one by one. The first watch was set. Commander Michael Siedsma, a 21-year Navy veteran, took command.

What’s Actually Inside a $2.8 Billion Submarine

The USS Massachusetts stretches 377 feet long, weighs roughly 8,000 tons, and can dive deeper than 800 feet. More than half of that length is occupied by a nuclear reactor powerful enough to run a small city.

It carries 24 Tomahawk cruise missiles, torpedoes, and what the Navy calls “enhanced stealth” and “sophisticated surveillance capabilities.” It can travel faster than 25 knots.

Only about 30 feet of the sub sits above the waterline. From the surface, it looks like not much. Below the surface, it is one of the most lethal machines the Navy operates.

The crew of 147 includes 39 women, making up roughly 25 percent of the sailors onboard. The submarine ban on women was lifted 16 years ago, and the USS New Jersey, commissioned in 2024, was the first sub specifically designed and built for a gender-integrated crew. The USS Massachusetts follows that design.

Ship sponsor Sheryl Sandberg, the former COO of Meta, put it plainly: “Those sailors just don’t inspire me. They inspire every little girl out there to believe that she could do anything.”

The Details You Won’t Find Anywhere Else

The submarine bakes fresh bread every single day. It is the only class of Navy vessel with deep fryers onboard. On the day reporters toured the sub, the crew was making hamburgers and French fries.

In the officers’ dining room, a custom mug rack hangs on the wall, made from wood sourced from every county in Massachusetts. It was donated by “This Old House,” the long-running television show. Commander Siedsma called it “beautiful” and “an incredible connection to the state and the commonwealth.”

That same dining table doubles as a surgery table in emergencies.

The sub took six years to build. General Dynamics Electric Boat and Newport News Shipbuilding co-produced it, with sections barged between facilities in Virginia. It was christened in May 2023 and completed sea trials, including its first submersion and high-speed underwater maneuvers, by October.

181 Years of Ships Named Massachusetts

This is the sixth U.S. Navy vessel to carry the state’s name, but the first submarine. The lineage stretches back to 1845, when a wooden steamer saw action in the Mexican-American War.

The most famous was BB-59, known as “Big Mamie” to her crew. Commissioned in 1942, she earned 11 battle stars across nearly every major Pacific campaign of World War II. She was decommissioned in 1947 and now sits as a museum ship in Fall River.

The new sub’s chief of boat, Edward Brennan III, the senior enlisted sailor onboard, is from Fall River.

After the commissioning, the USS Massachusetts will submerge and head out for additional training before awaiting deployment orders. Commander Siedsma did not say where the sub would go, but the timing is notable: a U.S. submarine sank an Iranian warship off the coast of Sri Lanka earlier this month.

“The geopolitical situation right now is interesting,” Siedsma said. “We’re always trained and ready to fight.”