Nik is the lead fitter in The Big House.

The Big House is the fabrication shop at Dakota Creek Shipyard in Anacortes, where America’s Finest is being built. Think of the ship as a Lego set. A large part of the set — a building, maybe — is built from standard blocks. Within that building, though, there might be chairs, or a desk with a tiny Lego computer on it. A truck in the garage.

The fab shop builds those parts. Winch housings, for example, to support the motors that will haul in the ship’s nets and lines. The radio mast. Most notably, because it’s enormous, the ship’s superstructure.

Being lead fitter is like being the master puzzle-builder. Someone has to read the plans and ensure the pieces come together precisely. Make sure that when the superstructure is lowered onto the deck of the main ship, which is being built across the street, it fits like an egg in a nest. That’s the lead fitter’s job.

On a Tuesday afternoon, The Big House is quiet. The shift is over. The main floor of the shop is largely empty, but the superstructure looms in one end of the building. It’s two stories high, and bigger than many apartments.

The lower section, or story, is built of steel, and will join with the finished hull. The upper story, which will house the ship’s bridge, or command center, is built of aluminum.

Altogether, the superstructure contains an unfathomable number of pieces.

In very basic ways, it’s not much different than framing a house. The superstructure has it’s equivalent of studs and blocking and braces and joists and rafters. It is sheathed just like a house, with sheets of aluminum, and holes for windows will be cut in the sheathing.

Nik’s job is to make sure the thousands of pieces all come together without error.

In shipbuilding, measurements are made in millimeters. There are 25.4 millimeters in an inch. America’s Finest will be 262 feet long. That’s 3,144 inches, or 79,858 millimeters.

If a measurement is off by one millimeter over the length of a foot, it might not seem like much. But if you multiply that error the length of the ship, that’s 262 millimeters off. That’s more than 10 inches. And 10 inches is a large hole in anything, but especially in a ship.

Being a lead fitter is like being a master puzzle-builder with much at stake.

“It’s fun,” Nik said. “It’s challenging. You’re excited to come to work.”