Three giant new container cranes, among the largest ever installed at a U.S. port, are on their way across the ocean from China, and they are set make the Port of Oakland home by late December.

The 300-foot-tall cranes, which rise to 400 feet when their booms are raised to their highest position, were manufactured by Shanghai-based ZPMC and are arriving in the Bay soon via a specially designed ship, as KPIX reports. They will be installed at the Oakland International Container Terminal, and they're being paid for by Stevedoring Services of America (SSA) to the tune of $30 million.

At their highest, the cranes will stand as tall as 40-story buildings — or about the height of Embarcadero Center.

"These cranes will keep the Port of Oakland competitive so that we can continue to attract the largest vessels calling North America," says Port of Oakland Executive Director Danny Wan in a statement. "Ultimately, bigger cranes at our waterfront translate into maritime and related jobs for the region."

The new cranes will able to lift containers up to 174 feet above the dock, and reach 225 feet across ship decks.

"Taller cranes are needed for efficiently handling cargo that arrives on ultra-large container ships,” said SSA Containers President Edward DeNike in a statement to Maritime Professional. "This new infrastructure is a commitment to the Port that we will continue our maritime business at Oakland well into the future."

The port is removing three older cranes in order to make room for the new ones.

"There’s no better demonstration of our maritime partner’s faith in the Port of Oakland, than investing in these huge ship-to-shore cranes," says Port of Oakland Maritime Director Bryan Brandes.

Earlier this year, the Port of Oakland was visited by one such ultra-large ship for which these cranes might have made work easier. That ship, the MSC Anna, is 1,312 feet long, and its extra width and height made it a challenge to navigate under the Golden Gate and Bay bridges to get into port.

The Port of Oakland is the eighth busiest container port in the U.S.

Photo: Guillaume Merle